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* | | printk/nmi: generic solution for safe printk in NMIPetr Mladek2016-05-201-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | printk() takes some locks and could not be used a safe way in NMI context. The chance of a deadlock is real especially when printing stacks from all CPUs. This particular problem has been addressed on x86 by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). The patchset brings two big advantages. First, it makes the NMI backtraces safe on all architectures for free. Second, it makes all NMI messages almost safe on all architectures (the temporary buffer is limited. We still should keep the number of messages in NMI context at minimum). Note that there already are several messages printed in NMI context: WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE handlers. These are not easy to avoid. This patch reuses most of the code and makes it generic. It is useful for all messages and architectures that support NMI. The alternative printk_func is set when entering and is reseted when leaving NMI context. It queues IRQ work to copy the messages into the main ring buffer in a safe context. __printk_nmi_flush() copies all available messages and reset the buffer. Then we could use a simple cmpxchg operations to get synchronized with writers. There is also used a spinlock to get synchronized with other flushers. We do not longer use seq_buf because it depends on external lock. It would be hard to make all supported operations safe for a lockless use. It would be confusing and error prone to make only some operations safe. The code is put into separate printk/nmi.c as suggested by Steven Rostedt. It needs a per-CPU buffer and is compiled only on architectures that call nmi_enter(). This is achieved by the new HAVE_NMI Kconfig flag. The are MN10300 and Xtensa architectures. We need to clean up NMI handling there first. Let's do it separately. The patch is heavily based on the draft from Peter Zijlstra, see https://lkml.org/lkml/2015/6/10/327 [arnd@arndb.de: printk-nmi: use %zu format string for size_t] [akpm@linux-foundation.org: min_t->min - all types are size_t here] Signed-off-by: Petr Mladek <pmladek@suse.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jan Kara <jack@suse.cz> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> [arm part] Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: SLAB freelist randomizationThomas Garnier2016-05-191-0/+9
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provides an optional config (CONFIG_SLAB_FREELIST_RANDOM) to randomize the SLAB freelist. The list is randomized during initialization of a new set of pages. The order on different freelist sizes is pre-computed at boot for performance. Each kmem_cache has its own randomized freelist. Before pre-computed lists are available freelists are generated dynamically. This security feature reduces the predictability of the kernel SLAB allocator against heap overflows rendering attacks much less stable. For example this attack against SLUB (also applicable against SLAB) would be affected: https://jon.oberheide.org/blog/2010/09/10/linux-kernel-can-slub-overflow/ Also, since v4.6 the freelist was moved at the end of the SLAB. It means a controllable heap is opened to new attacks not yet publicly discussed. A kernel heap overflow can be transformed to multiple use-after-free. This feature makes this type of attack harder too. To generate entropy, we use get_random_bytes_arch because 0 bits of entropy is available in the boot stage. In the worse case this function will fallback to the get_random_bytes sub API. We also generate a shift random number to shift pre-computed freelist for each new set of pages. The config option name is not specific to the SLAB as this approach will be extended to other allocators like SLUB. Performance results highlighted no major changes: Hackbench (running 90 10 times): Before average: 0.0698 After average: 0.0663 (-5.01%) slab_test 1 run on boot. Difference only seen on the 2048 size test being the worse case scenario covered by freelist randomization. New slab pages are constantly being created on the 10000 allocations. Variance should be mainly due to getting new pages every few allocations. Before: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 99 cycles kfree -> 112 cycles 10000 times kmalloc(16) -> 109 cycles kfree -> 140 cycles 10000 times kmalloc(32) -> 129 cycles kfree -> 137 cycles 10000 times kmalloc(64) -> 141 cycles kfree -> 141 cycles 10000 times kmalloc(128) -> 152 cycles kfree -> 148 cycles 10000 times kmalloc(256) -> 195 cycles kfree -> 167 cycles 10000 times kmalloc(512) -> 257 cycles kfree -> 199 cycles 10000 times kmalloc(1024) -> 393 cycles kfree -> 251 cycles 10000 times kmalloc(2048) -> 649 cycles kfree -> 228 cycles 10000 times kmalloc(4096) -> 806 cycles kfree -> 370 cycles 10000 times kmalloc(8192) -> 814 cycles kfree -> 411 cycles 10000 times kmalloc(16384) -> 892 cycles kfree -> 455 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 121 cycles 10000 times kmalloc(64)/kfree -> 121 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 121 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles After: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 130 cycles kfree -> 86 cycles 10000 times kmalloc(16) -> 118 cycles kfree -> 86 cycles 10000 times kmalloc(32) -> 121 cycles kfree -> 85 cycles 10000 times kmalloc(64) -> 176 cycles kfree -> 102 cycles 10000 times kmalloc(128) -> 178 cycles kfree -> 100 cycles 10000 times kmalloc(256) -> 205 cycles kfree -> 109 cycles 10000 times kmalloc(512) -> 262 cycles kfree -> 136 cycles 10000 times kmalloc(1024) -> 342 cycles kfree -> 157 cycles 10000 times kmalloc(2048) -> 701 cycles kfree -> 238 cycles 10000 times kmalloc(4096) -> 803 cycles kfree -> 364 cycles 10000 times kmalloc(8192) -> 835 cycles kfree -> 404 cycles 10000 times kmalloc(16384) -> 896 cycles kfree -> 441 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 123 cycles 10000 times kmalloc(64)/kfree -> 142 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 119 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles [akpm@linux-foundation.org: propagate gfp_t into cache_random_seq_create()] Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Thelen <gthelen@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Make CONFIG_FHANDLE default yAndi Kleen2016-04-011-1/+2
|/ | | | | | | | | | | | | | | | | | | | Newer Fedora and OpenSUSE didn't boot with my standard configuration. It took me some time to figure out why, in fact I had to write a script to try different config options systematically. The problem is that something (systemd) in dracut depends on CONFIG_FHANDLE, which adds open by file handle syscalls. While it is set in defconfigs it is very easy to miss when updating older configs because it is not default y. Make it default y and also depend on EXPERT, as dracut use is likely widespread. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Richard Weinberger <richard.weinberger@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-4.6' of ↵Linus Torvalds2016-03-181-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "cgroup changes for v4.6-rc1. No userland visible behavior changes in this pull request. I'll send out a separate pull request for the addition of cgroup namespace support. - The biggest change is the revamping of cgroup core task migration and controller handling logic. There are quite a few places where controllers and tasks are manipulated. Previously, many of those places implemented custom operations for each specific use case assuming specific starting conditions. While this worked, it makes the code fragile and difficult to follow. The bulk of this pull request restructures these operations so that most related operations are performed through common helpers which implement recursive (subtrees are always processed consistently) and idempotent (they make cgroup hierarchy converge to the target state rather than performing operations assuming specific starting conditions). This makes the code a lot easier to understand, verify and extend. - Implicit controller support is added. This is primarily for using perf_event on the v2 hierarchy so that perf can match cgroup v2 path without requiring the user to do anything special. The kernel portion of perf_event changes is acked but userland changes are still pending review. - cgroup_no_v1= boot parameter added to ease testing cgroup v2 in certain environments. - There is a regression introduced during v4.4 devel cycle where attempts to migrate zombie tasks can mess up internal object management. This was fixed earlier this week and included in this pull request w/ stable cc'd. - Misc non-critical fixes and improvements" * 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (44 commits) cgroup: avoid false positive gcc-6 warning cgroup: ignore css_sets associated with dead cgroups during migration Documentation: cgroup v2: Trivial heading correction. cgroup: implement cgroup_subsys->implicit_on_dfl cgroup: use css_set->mg_dst_cgrp for the migration target cgroup cgroup: make cgroup[_taskset]_migrate() take cgroup_root instead of cgroup cgroup: move migration destination verification out of cgroup_migrate_prepare_dst() cgroup: fix incorrect destination cgroup in cgroup_update_dfl_csses() cgroup: Trivial correction to reflect controller. cgroup: remove stale item in cgroup-v1 document INDEX file. cgroup: update css iteration in cgroup_update_dfl_csses() cgroup: allocate 2x cgrp_cset_links when setting up a new root cgroup: make cgroup_calc_subtree_ss_mask() take @this_ss_mask cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends cgroup: use cgroup_apply_enable_control() in cgroup creation path cgroup: combine cgroup_mutex locking and offline css draining cgroup: factor out cgroup_{apply|finalize}_control() from cgroup_subtree_control_write() cgroup: introduce cgroup_{save|propagate|restore}_control() cgroup: make cgroup_drain_offline() and cgroup_apply_control_{disable|enable}() recursive cgroup: factor out cgroup_apply_control_enable() from cgroup_subtree_control_write() ...
| * cgroup: Trivial correction to reflect controller.Parav Pandit2016-03-051-2/+2
| | | | | | | | | | | | | | | | | | Trivial correction in menuconfig help to reflect PIDs as controller instead of subsystem to align to rest of the text and documentation. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | Merge branch 'next' of ↵Linus Torvalds2016-03-171-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security layer updates from James Morris: "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor fixes scattered across the subsystem. IMA now requires signed policy, and that policy is also now measured and appraised" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits) X.509: Make algo identifiers text instead of enum akcipher: Move the RSA DER encoding check to the crypto layer crypto: Add hash param to pkcs1pad sign-file: fix build with CMS support disabled MAINTAINERS: update tpmdd urls MODSIGN: linux/string.h should be #included to get memcpy() certs: Fix misaligned data in extra certificate list X.509: Handle midnight alternative notation in GeneralizedTime X.509: Support leap seconds Handle ISO 8601 leap seconds and encodings of midnight in mktime64() X.509: Fix leap year handling again PKCS#7: fix unitialized boolean 'want' firmware: change kernel read fail to dev_dbg() KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert KEYS: Reserve an extra certificate symbol for inserting without recompiling modsign: hide openssl output in silent builds tpm_tis: fix build warning with tpm_tis_resume ima: require signed IMA policy ima: measure and appraise the IMA policy itself ima: load policy using path ...
| * | akcipher: Move the RSA DER encoding check to the crypto layerDavid Howells2016-03-031-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key subtype to the rsa crypto module's pkcs1pad template. This means that the public_key subtype no longer has any dependencies on public key type. To make this work, the following changes have been made: (1) The rsa pkcs1pad template is now used for RSA keys. This strips off the padding and returns just the message hash. (2) In a previous patch, the pkcs1pad template gained an optional second parameter that, if given, specifies the hash used. We now give this, and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5 encoding and verifies that the correct digest OID is present. (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to something that doesn't care about what the encryption actually does and and has been merged into public_key.c. (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone. Module signing must set CONFIG_CRYPTO_RSA=y instead. Thoughts: (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to the padding template? Should there be multiple padding templates registered that share most of the code? Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
* | kallsyms: add support for relative offsets in kallsyms address tableArd Biesheuvel2016-03-151-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to how relative extables are implemented, it is possible to emit the kallsyms table in such a way that it contains offsets relative to some anchor point in the kernel image rather than absolute addresses. On 64-bit architectures, it cuts the size of the kallsyms address table in half, since offsets between kernel symbols can typically be expressed in 32 bits. This saves several hundreds of kilobytes of permanent .rodata on average. In addition, the kallsyms address table is no longer subject to dynamic relocation when CONFIG_RELOCATABLE is in effect, so the relocation work done after decompression now doesn't have to do relocation updates for all these values. This saves up to 24 bytes (i.e., the size of a ELF64 RELA relocation table entry) per value, which easily adds up to a couple of megabytes of uncompressed __init data on ppc64 or arm64. Even if these relocation entries typically compress well, the combined size reduction of 2.8 MB uncompressed for a ppc64_defconfig build (of which 2.4 MB is __init data) results in a ~500 KB space saving in the compressed image. Since it is useful for some architectures (like x86) to retain the ability to emit absolute values as well, this patch also adds support for capturing both absolute and relative values when KALLSYMS_ABSOLUTE_PERCPU is in effect, by emitting absolute per-cpu addresses as positive 32-bit values, and addresses relative to the lowest encountered relative symbol as negative values, which are subtracted from the runtime address of this base symbol to produce the actual address. Support for the above is enabled by default for all architectures except IA-64 and Tile-GX, whose symbols are too far apart to capture in this manner. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | x86: kallsyms: disable absolute percpu symbols on !SMPArd Biesheuvel2016-03-151-0/+4
|/ | | | | | | | | | | | | | | | | | | | | | | scripts/kallsyms.c has a special --absolute-percpu command line option which deals with the zero based per cpu offsets that are used when building for SMP on x86_64. This means that the option should only be passed in that case, so add a Kconfig symbol with the correct predicate, and use that instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: rein in the CONFIG space madnessJohannes Weiner2016-01-201-18/+3
| | | | | | | | | | | | | What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory controller code is insignificant, having these conditionals is not worth the complication and fragility that comes with them. [akpm@linux-foundation.org: rework mem_cgroup_css_free() statement ordering] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEMJohannes Weiner2016-01-201-1/+9
| | | | | | | | | | | | | | Let the user know that CONFIG_MEMCG_KMEM does not apply to the cgroup2 interface. This also makes legacy-only code sections stand out better. [arnd@arndb.de: mm: memcontrol: only manage socket pressure for CONFIG_INET] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds2016-01-171-8/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull audit updates from Paul Moore: "Seven audit patches for 4.5, all very minor despite the diffstat. The diffstat churn for linux/audit.h can be attributed to needing to reshuffle the linux/audit.h header to fix the seccomp auditing issue (see the commit description for details). Besides the seccomp/audit fix, most of the fixes are around trying to improve the connection with the audit daemon and a Kconfig simplification. Nothing crazy, and everything passes our little audit-testsuite" * 'upstream' of git://git.infradead.org/users/pcmoore/audit: audit: always enable syscall auditing when supported and audit is enabled audit: force seccomp event logging to honor the audit_enabled flag audit: Delete unnecessary checks before two function calls audit: wake up threads if queue switched from limited to unlimited audit: include auditd's threads in audit_log_start() wait exception audit: remove audit_backlog_wait_overflow audit: don't needlessly reset valid wait time
| * audit: always enable syscall auditing when supported and audit is enabledPaul Moore2016-01-131-8/+3
| | | | | | | | | | | | | | | | | | To the best of our knowledge, everyone who enables audit at compile time also enables syscall auditing; this patch simplifies the Kconfig menus by removing the option to disable syscall auditing when audit is selected and the target arch supports it. Signed-off-by: Paul Moore <pmoore@redhat.com>
* | uselib: default depending if libc5 was usedRiku Voipio2016-01-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uselib hasn't been used since libc5; glibc does not use it. Deprecate uselib a bit more, by making the default y only if libc5 was widely used on the plaform. This makes arm64 kernel built with defconfig slightly smaller bloat-o-meter: add/remove: 0/3 grow/shrink: 0/2 up/down: 0/-1390 (-1390) function old new delta kernel_config_data 18164 18162 -2 uselib_flags 20 - -20 padzero 216 192 -24 sys_uselib 380 - -380 load_elf_library 964 - -964 Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-4.5' of ↵Linus Torvalds2016-01-121-127/+114
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - cgroup v2 interface is now official. It's no longer hidden behind a devel flag and can be mounted using the new cgroup2 fs type. Unfortunately, cpu v2 interface hasn't made it yet due to the discussion around in-process hierarchical resource distribution and only memory and io controllers can be used on the v2 interface at the moment. - The existing documentation which has always been a bit of mess is relocated under Documentation/cgroup-v1/. Documentation/cgroup-v2.txt is added as the authoritative documentation for the v2 interface. - Some features are added through for-4.5-ancestor-test branch to enable netfilter xt_cgroup match to use cgroup v2 paths. The actual netfilter changes will be merged through the net tree which pulled in the said branch. - Various cleanups * 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: rename cgroup documentations cgroup: fix a typo. cgroup: Remove resource_counter.txt in Documentation/cgroup-legacy/00-INDEX. cgroup: demote subsystem init messages to KERN_DEBUG cgroup: Fix uninitialized variable warning cgroup: put controller Kconfig options in meaningful order cgroup: clean up the kernel configuration menu nomenclature cgroup_pids: fix a typo. Subject: cgroup: Fix incomplete dd command in blkio documentation cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends cpuset: Replace all instances of time_t with time64_t cgroup: replace unified-hierarchy.txt with a proper cgroup v2 documentation cgroup: rename Documentation/cgroups/ to Documentation/cgroup-legacy/ cgroup: replace __DEVEL__sane_behavior with cgroup2 fs type
| * cgroup: put controller Kconfig options in meaningful orderJohannes Weiner2015-12-181-107/+107
| | | | | | | | | | | | | | | | | | | | | | | | To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: clean up the kernel configuration menu nomenclatureJohannes Weiner2015-12-181-39/+26
| | | | | | | | | | | | | | | | | | The config options for the different cgroup controllers use various terms: resource controller, cgroup subsystem, etc. Simplify this to "controller", which is clear enough in the cgroup context. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | kernel: remove stop_machine() Kconfig dependencyChris Wilson2015-12-121-7/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the full stop_machine() routine is only enabled on SMP if module unloading is enabled, or if the CPUs are hotpluggable. This leads to configurations where stop_machine() is broken as it will then only run the callback on the local CPU with irqs disabled, and not stop the other CPUs or run the callback on them. For example, this breaks MTRR setup on x86 in certain configs since ea8596bb2d8d379 ("kprobes/x86: Remove unused text_poke_smp() and text_poke_smp_batch() functions") as the MTRR is only established on the boot CPU. This patch removes the Kconfig option for STOP_MACHINE and uses the SMP and HOTPLUG_CPU config options to compile the correct stop_machine() for the architecture, removing the false dependency on MODULE_UNLOAD in the process. Link: https://lkml.org/lkml/2014/10/8/124 References: https://bugs.freedesktop.org/show_bug.cgi?id=84794 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Iulia Manda <iulia.manda21@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sys_membarrier(): system-wide memory barrier (generic, x86)Mathieu Desnoyers2015-09-111-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here is an implementation of a new system call, sys_membarrier(), which executes a memory barrier on all threads running on the system. It is implemented by calling synchronize_sched(). It can be used to distribute the cost of user-space memory barriers asymmetrically by transforming pairs of memory barriers into pairs consisting of sys_membarrier() and a compiler barrier. For synchronization primitives that distinguish between read-side and write-side (e.g. userspace RCU [1], rwlocks), the read-side can be accelerated significantly by moving the bulk of the memory barrier overhead to the write-side. The existing applications of which I am aware that would be improved by this system call are as follows: * Through Userspace RCU library (http://urcu.so) - DNS server (Knot DNS) https://www.knot-dns.cz/ - Network sniffer (http://netsniff-ng.org/) - Distributed object storage (https://sheepdog.github.io/sheepdog/) - User-space tracing (http://lttng.org) - Network storage system (https://www.gluster.org/) - Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf) - Financial software (https://lkml.org/lkml/2015/3/23/189) Those projects use RCU in userspace to increase read-side speed and scalability compared to locking. Especially in the case of RCU used by libraries, sys_membarrier can speed up the read-side by moving the bulk of the memory barrier cost to synchronize_rcu(). * Direct users of sys_membarrier - core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198) Microsoft core dotnet GC developers are planning to use the mprotect() side-effect of issuing memory barriers through IPIs as a way to implement Windows FlushProcessWriteBuffers() on Linux. They are referring to sys_membarrier in their github thread, specifically stating that sys_membarrier() is what they are looking for. To explain the benefit of this scheme, let's introduce two example threads: Thread A (non-frequent, e.g. executing liburcu synchronize_rcu()) Thread B (frequent, e.g. executing liburcu rcu_read_lock()/rcu_read_unlock()) In a scheme where all smp_mb() in thread A are ordering memory accesses with respect to smp_mb() present in Thread B, we can change each smp_mb() within Thread A into calls to sys_membarrier() and each smp_mb() within Thread B into compiler barriers "barrier()". Before the change, we had, for each smp_mb() pairs: Thread A Thread B previous mem accesses previous mem accesses smp_mb() smp_mb() following mem accesses following mem accesses After the change, these pairs become: Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses As we can see, there are two possible scenarios: either Thread B memory accesses do not happen concurrently with Thread A accesses (1), or they do (2). 1) Non-concurrent Thread A vs Thread B accesses: Thread A Thread B prev mem accesses sys_membarrier() follow mem accesses prev mem accesses barrier() follow mem accesses In this case, thread B accesses will be weakly ordered. This is OK, because at that point, thread A is not particularly interested in ordering them with respect to its own accesses. 2) Concurrent Thread A vs Thread B accesses Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses In this case, thread B accesses, which are ensured to be in program order thanks to the compiler barrier, will be "upgraded" to full smp_mb() by synchronize_sched(). * Benchmarks On Intel Xeon E5405 (8 cores) (one thread is calling sys_membarrier, the other 7 threads are busy looping) 1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call. * User-space user of this system call: Userspace RCU library Both the signal-based and the sys_membarrier userspace RCU schemes permit us to remove the memory barrier from the userspace RCU rcu_read_lock() and rcu_read_unlock() primitives, thus significantly accelerating them. These memory barriers are replaced by compiler barriers on the read-side, and all matching memory barriers on the write-side are turned into an invocation of a memory barrier on all active threads in the process. By letting the kernel perform this synchronization rather than dumbly sending a signal to every process threads (as we currently do), we diminish the number of unnecessary wake ups and only issue the memory barriers on active threads. Non-running threads do not need to execute such barrier anyway, because these are implied by the scheduler context switches. Results in liburcu: Operations in 10s, 6 readers, 2 writers: memory barriers in reader: 1701557485 reads, 2202847 writes signal-based scheme: 9830061167 reads, 6700 writes sys_membarrier: 9952759104 reads, 425 writes sys_membarrier (dyn. check): 7970328887 reads, 425 writes The dynamic sys_membarrier availability check adds some overhead to the read-side compared to the signal-based scheme, but besides that, sys_membarrier slightly outperforms the signal-based scheme. However, this non-expedited sys_membarrier implementation has a much slower grace period than signal and memory barrier schemes. Besides diminishing the number of wake-ups, one major advantage of the membarrier system call over the signal-based scheme is that it does not need to reserve a signal. This plays much more nicely with libraries, and with processes injected into for tracing purposes, for which we cannot expect that signals will be unused by the application. An expedited version of this system call can be added later on to speed up the grace period. Its implementation will likely depend on reading the cpu_curr()->mm without holding each CPU's rq lock. This patch adds the system call to x86 and to asm-generic. [1] http://urcu.so membarrier(2) man page: MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2) NAME membarrier - issue memory barriers on a set of threads SYNOPSIS #include <linux/membarrier.h> int membarrier(int cmd, int flags); DESCRIPTION The cmd argument is one of the following: MEMBARRIER_CMD_QUERY Query the set of supported commands. It returns a bitmask of supported commands. MEMBARRIER_CMD_SHARED Execute a memory barrier on all threads running on the system. Upon return from system call, the caller thread is ensured that all running threads have passed through a state where all memory accesses to user-space addresses match program order between entry to and return from the system call (non-running threads are de facto in such a state). This covers threads from all pro=E2=80=90 cesses running on the system. This command returns 0. The flags argument needs to be 0. For future extensions. All memory accesses performed in program order from each targeted thread is guaranteed to be ordered with respect to sys_membarrier(). If we use the semantic "barrier()" to represent a compiler barrier forcing memory accesses to be performed in program order across the barrier, and smp_mb() to represent explicit memory barriers forcing full memory ordering across the barrier, we have the following ordering table for each pair of barrier(), sys_membarrier() and smp_mb(): The pair ordering is detailed as (O: ordered, X: not ordered): barrier() smp_mb() sys_membarrier() barrier() X X O smp_mb() X O O sys_membarrier() O O O RETURN VALUE On success, these system calls return zero. On error, -1 is returned, and errno is set appropriately. For a given command, with flags argument set to 0, this system call is guaranteed to always return the same value until reboot. ERRORS ENOSYS System call is not implemented. EINVAL Invalid arguments. Linux 2015-04-15 MEMBARRIER(2) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Miell <nmiell@comcast.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'next' of ↵Linus Torvalds2015-09-081-19/+21
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - PKCS#7 support added to support signed kexec, also utilized for module signing. See comments in 3f1e1bea. ** NOTE: this requires linking against the OpenSSL library, which must be installed, e.g. the openssl-devel on Fedora ** - Smack - add IPv6 host labeling; ignore labels on kernel threads - support smack labeling mounts which use binary mount data - SELinux: - add ioctl whitelisting (see http://kernsec.org/files/lss2015/vanderstoep.pdf) - fix mprotect PROT_EXEC regression caused by mm change - Seccomp: - add ptrace options for suspend/resume" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (57 commits) PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them Documentation/Changes: Now need OpenSSL devel packages for module signing scripts: add extract-cert and sign-file to .gitignore modsign: Handle signing key in source tree modsign: Use if_changed rule for extracting cert from module signing key Move certificate handling to its own directory sign-file: Fix warning about BIO_reset() return value PKCS#7: Add MODULE_LICENSE() to test module Smack - Fix build error with bringup unconfigured sign-file: Document dependency on OpenSSL devel libraries PKCS#7: Appropriately restrict authenticated attributes and content type KEYS: Add a name for PKEY_ID_PKCS7 PKCS#7: Improve and export the X.509 ASN.1 time object decoder modsign: Use extract-cert to process CONFIG_SYSTEM_TRUSTED_KEYS extract-cert: Cope with multiple X.509 certificates in a single file sign-file: Generate CMS message as signature instead of PKCS#7 PKCS#7: Support CMS messages also [RFC5652] X.509: Change recorded SKID & AKID to not include Subject or Issuer PKCS#7: Check content type and versions MAINTAINERS: The keyrings mailing list has moved ...
| * Move certificate handling to its own directoryDavid Howells2015-08-141-39/+0
| | | | | | | | | | | | | | | | | | Move certificate handling out of the kernel/ directory and into a certs/ directory to get all the weird stuff in one place and move the generated signing keys into this directory. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
| * sign-file: Document dependency on OpenSSL devel librariesDavid Howells2015-08-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | The revised sign-file program is no longer a script that wraps the openssl program, but now rather a program that makes use of OpenSSL's crypto library. This means that to build the sign-file program, the kernel build process now has a dependency on the OpenSSL development packages in addition to OpenSSL itself. Document this in Kconfig and in module-signing.txt. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
| * modsign: Add explicit CONFIG_SYSTEM_TRUSTED_KEYS optionDavid Woodhouse2015-08-071-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let the user explicitly provide a file containing trusted keys, instead of just automatically finding files matching *.x509 in the build tree and trusting whatever we find. This really ought to be an *explicit* configuration, and the build rules for dealing with the files were fairly painful too. Fix applied from James Morris that removes an '=' from a macro definition in kernel/Makefile as this is a feature that only exists from GNU make 3.82 onwards. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
| * modsign: Use single PEM file for autogenerated keyDavid Woodhouse2015-08-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current rule for generating signing_key.priv and signing_key.x509 is a classic example of a bad rule which has a tendency to break parallel make. When invoked to create *either* target, it generates the other target as a side-effect that make didn't predict. So let's switch to using a single file signing_key.pem which contains both key and certificate. That matches what we do in the case of an external key specified by CONFIG_MODULE_SIG_KEY anyway, so it's also slightly cleaner. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
| * modsign: Extract signing cert from CONFIG_MODULE_SIG_KEY if neededDavid Woodhouse2015-08-071-4/+4
| | | | | | | | | | | | | | | | | | Where an external PEM file or PKCS#11 URI is given, we can get the cert from it for ourselves instead of making the user drop signing_key.x509 in place for us. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
| * modsign: Allow external signing key to be specifiedDavid Woodhouse2015-08-071-0/+14
| | | | | | | | | | Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
| * MODSIGN: Extract the blob PKCS#7 signature verifier from module signingDavid Howells2015-08-071-10/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Extract the function that drives the PKCS#7 signature verification given a data blob and a PKCS#7 blob out from the module signing code and lump it with the system keyring code as it's generic. This makes it independent of module config options and opens it to use by the firmware loader. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ming Lei <ming.lei@canonical.com> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Kyle McMartin <kyle@kernel.org>
| * MODSIGN: Use PKCS#7 messages as module signaturesDavid Howells2015-08-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move to using PKCS#7 messages as module signatures because: (1) We have to be able to support the use of X.509 certificates that don't have a subjKeyId set. We're currently relying on this to look up the X.509 certificate in the trusted keyring list. (2) PKCS#7 message signed information blocks have a field that supplies the data required to match with the X.509 certificate that signed it. (3) The PKCS#7 certificate carries fields that specify the digest algorithm used to generate the signature in a standardised way and the X.509 certificates specify the public key algorithm in a standardised way - so we don't need our own methods of specifying these. (4) We now have PKCS#7 message support in the kernel for signed kexec purposes and we can make use of this. To make this work, the old sign-file script has been replaced with a program that needs compiling in a previous patch. The rules to build it are added here. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Vivek Goyal <vgoyal@redhat.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2015-09-051-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "In this one: - d_move fixes (Eric Biederman) - UFS fixes (me; locking is mostly sane now, a bunch of bugs in error handling ought to be fixed) - switch of sb_writers to percpu rwsem (Oleg Nesterov) - superblock scalability (Josef Bacik and Dave Chinner) - swapon(2) race fix (Hugh Dickins)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits) vfs: Test for and handle paths that are unreachable from their mnt_root dcache: Reduce the scope of i_lock in d_splice_alias dcache: Handle escaped paths in prepend_path mm: fix potential data race in SyS_swapon inode: don't softlockup when evicting inodes inode: rename i_wb_list to i_io_list sync: serialise per-superblock sync operations inode: convert inode_sb_list_lock to per-sb inode: add hlist_fake to avoid the inode hash lock in evict writeback: plug writeback at a high level change sb_writers to use percpu_rw_semaphore shift percpu_counter_destroy() into destroy_super_work() percpu-rwsem: kill CONFIG_PERCPU_RWSEM percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire() percpu-rwsem: introduce percpu_down_read_trylock() document rwsem_release() in sb_wait_write() fix the broken lockdep logic in __sb_start_write() introduce __sb_writers_{acquired,release}() helpers ufs_inode_get{frag,block}(): get rid of 'phys' argument ufs_getfrag_block(): tidy up a bit ...
| * | percpu-rwsem: kill CONFIG_PERCPU_RWSEMOleg Nesterov2015-08-151-1/+0
| |/ | | | | | | | | | | | | Remove CONFIG_PERCPU_RWSEM, the next patch adds the unconditional user of percpu_rw_semaphore. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2015-09-051-0/+18
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge patch-bomb from Andrew Morton: - a few misc things - Andy's "ambient capabilities" - fs/nofity updates - the ocfs2 queue - kernel/watchdog.c updates and feature work. - some of MM. Includes Andrea's userfaultfd feature. [ Hadn't noticed that userfaultfd was 'default y' when applying the patches, so that got fixed in this merge instead. We do _not_ mark new features that nobody uses yet 'default y' - Linus ] * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits) mm/hugetlb.c: make vma_has_reserves() return bool mm/madvise.c: make madvise_behaviour_valid() return bool mm/memory.c: make tlb_next_batch() return bool mm/dmapool.c: change is_page_busy() return from int to bool mm: remove struct node_active_region mremap: simplify the "overlap" check in mremap_to() mremap: don't do uneccesary checks if new_len == old_len mremap: don't do mm_populate(new_addr) on failure mm: move ->mremap() from file_operations to vm_operations_struct mremap: don't leak new_vma if f_op->mremap() fails mm/hugetlb.c: make vma_shareable() return bool mm: make GUP handle pfn mapping unless FOLL_GET is requested mm: fix status code which move_pages() returns for zero page mm: memcontrol: bring back the VM_BUG_ON() in mem_cgroup_swapout() genalloc: add support of multiple gen_pools per device genalloc: add name arg to gen_pool_get() and devm_gen_pool_create() mm/memblock: WARN_ON when nid differs from overlap region Documentation/features/vm: add feature description and arch support status for batched TLB flush after unmap mm: defer flush of writable TLB entries mm: send one IPI per CPU to TLB flush all entries after unmapping pages ...
| * | mm: send one IPI per CPU to TLB flush all entries after unmapping pagesMel Gorman2015-09-041-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An IPI is sent to flush remote TLBs when a page is unmapped that was potentially accesssed by other CPUs. There are many circumstances where this happens but the obvious one is kswapd reclaiming pages belonging to a running process as kswapd and the task are likely running on separate CPUs. On small machines, this is not a significant problem but as machine gets larger with more cores and more memory, the cost of these IPIs can be high. This patch uses a simple structure that tracks CPUs that potentially have TLB entries for pages being unmapped. When the unmapping is complete, the full TLB is flushed on the assumption that a refill cost is lower than flushing individual entries. Architectures wishing to do this must give the following guarantee. If a clean page is unmapped and not immediately flushed, the architecture must guarantee that a write to that linear address from a CPU with a cached TLB entry will trap a page fault. This is essentially what the kernel already depends on but the window is much larger with this patch applied and is worth highlighting. The architecture should consider whether the cost of the full TLB flush is higher than sending an IPI to flush each individual entry. An additional architecture helper called flush_tlb_local is required. It's a trivial wrapper with some accounting in the x86 case. The impact of this patch depends on the workload as measuring any benefit requires both mapped pages co-located on the LRU and memory pressure. The case with the biggest impact is multiple processes reading mapped pages taken from the vm-scalability test suite. The test case uses NR_CPU readers of mapped files that consume 10*RAM. Linear mapped reader on a 4-node machine with 64G RAM and 48 CPUs 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 Ops lru-file-mmap-read-elapsed 159.62 ( 0.00%) 120.68 ( 24.40%) Ops lru-file-mmap-read-time_range 30.59 ( 0.00%) 2.80 ( 90.85%) Ops lru-file-mmap-read-time_stddv 6.70 ( 0.00%) 0.64 ( 90.38%) 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 User 581.00 611.43 System 5804.93 4111.76 Elapsed 161.03 122.12 This is showing that the readers completed 24.40% faster with 29% less system CPU time. From vmstats, it is known that the vanilla kernel was interrupted roughly 900K times per second during the steady phase of the test and the patched kernel was interrupts 180K times per second. The impact is lower on a single socket machine. 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 Ops lru-file-mmap-read-elapsed 25.33 ( 0.00%) 20.38 ( 19.54%) Ops lru-file-mmap-read-time_range 0.91 ( 0.00%) 1.44 (-58.24%) Ops lru-file-mmap-read-time_stddv 0.28 ( 0.00%) 0.47 (-65.34%) 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 User 58.09 57.64 System 111.82 76.56 Elapsed 27.29 22.55 It's still a noticeable improvement with vmstat showing interrupts went from roughly 500K per second to 45K per second. The patch will have no impact on workloads with no memory pressure or have relatively few mapped pages. It will have an unpredictable impact on the workload running on the CPU being flushed as it'll depend on how many TLB entries need to be refilled and how long that takes. Worst case, the TLB will be completely cleared of active entries when the target PFNs were not resident at all. [sasha.levin@oracle.com: trace tlb flush after disabling preemption in try_to_unmap_flush] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | userfaultfd: buildsystem activationAndrea Arcangeli2015-09-041-0/+11
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows to select the userfaultfd during configuration to build it. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-4.3' of ↵Linus Torvalds2015-09-021-0/+16
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - a new PIDs controller is added. It turns out that PIDs are actually an independent resource from kmem due to the limited PID space. - more core preparations for the v2 interface. Once cpu side interface is settled, it should be ready for lifting the devel mask. for-4.3-unified-base was temporarily branched so that other trees (block) can pull cgroup core changes that blkcg changes depend on. - a non-critical idr_preload usage bug fix. * 'for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: pids: fix invalid get/put usage cgroup: introduce cgroup_subsys->legacy_name cgroup: don't print subsystems for the default hierarchy cgroup: make cftype->private a unsigned long cgroup: export cgrp_dfl_root cgroup: define controller file conventions cgroup: fix idr_preload usage cgroup: add documentation for the PIDs controller cgroup: implement the PIDs subsystem cgroup: allow a cgroup subsystem to reject a fork
| * | cgroup: implement the PIDs subsystemAleksa Sarai2015-07-141-0/+16
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds a new single-purpose PIDs subsystem to limit the number of tasks that can be forked inside a cgroup. Essentially this is an implementation of RLIMIT_NPROC that applies to a cgroup rather than a process tree. However, it should be noted that organisational operations (adding and removing tasks from a PIDs hierarchy) will *not* be prevented. Rather, the number of tasks in the hierarchy cannot exceed the limit through forking. This is due to the fact that, in the unified hierarchy, attach cannot fail (and it is not possible for a task to overcome its PIDs cgroup policy limit by attaching to a child cgroup -- even if migrating mid-fork it must be able to fork in the parent first). PIDs are fundamentally a global resource, and it is possible to reach PID exhaustion inside a cgroup without hitting any reasonable kmemcg policy. Once you've hit PID exhaustion, you're only in a marginally better state than OOM. This subsystem allows PID exhaustion inside a cgroup to be prevented. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | rcu: Hide RCU_NOCB_CPU behind RCU_EXPERTPaul E. McKenney2015-07-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | This commit prevents Kconfig from asking the user about RCU_NOCB_CPU unless the user really wants to be asked. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de>
* | rcu: Drop RCU_USER_QS in favor of NO_HZ_FULLPaul E. McKenney2015-07-061-9/+0
|/ | | | | | | | | The RCU_USER_QS Kconfig parameter is now just a synonym for NO_HZ_FULL, so this commit eliminates RCU_USER_QS, replacing all uses with NO_HZ_FULL. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
* Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2015-07-041-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Debug info and other statistics fixes and related enhancements" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/numa: Fix numa balancing stats in /proc/pid/sched sched/numa: Show numa_group ID in /proc/sched_debug task listings sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h sched/stat: Expose /proc/pid/schedstat if CONFIG_SCHED_INFO=y sched/stat: Simplify the sched_info accounting dependency
| * sched/stat: Simplify the sched_info accounting dependencyNaveen N. Rao2015-07-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both CONFIG_SCHEDSTATS=y and CONFIG_TASK_DELAY_ACCT=y track task sched_info, which results in ugly #if clauses. Simplify the code by introducing a synthethic CONFIG_SCHED_INFO switch, selected by both. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: a.p.zijlstra@chello.nl Cc: ricklind@us.ibm.com Link: http://lkml.kernel.org/r/8d19eef800811a94b0f91bcbeb27430a884d7433.1435255405.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2015-07-041-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull max log buf size increase from Ingo Molnar: "Ran into this limit recently, so increase it by an order of magnitude" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: printk: Increase maximum CONFIG_LOG_BUF_SHIFT from 21 to 25
| * | printk: Increase maximum CONFIG_LOG_BUF_SHIFT from 21 to 25Ingo Molnar2015-07-011-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So I tried to some kernel debugging that produced a ton of kernel messages on a big box, and wanted to save them all: but CONFIG_LOG_BUF_SHIFT maxes out at 21 (2 MB). Increase it to 25 (32 MB). This does not affect any existing config or defaults. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge tag 'modules-next-for-linus' of ↵Linus Torvalds2015-07-011-15/+14
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
| * | modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.Rusty Russell2015-06-231-15/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACINGPeter Zijlstra2015-05-281-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrew worried about the overhead on small systems; only use the fancy code when either perf or tracing is enabled. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Requested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | | Merge branch 'for-4.2' of ↵Linus Torvalds2015-06-261-0/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - threadgroup_lock got reorganized so that its users can pick the actual locking mechanism to use. Its only user - cgroups - is updated to use a percpu_rwsem instead of per-process rwsem. This makes things a bit lighter on hot paths and allows cgroups to perform and fail multi-task (a process) migrations atomically. Multi-task migrations are used in several places including the unified hierarchy. - Delegation rule and documentation added to unified hierarchy. This will likely be the last interface update from the cgroup core side for unified hierarchy before lifting the devel mask. - Some groundwork for the pids controller which is scheduled to be merged in the coming devel cycle. * 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: add delegation section to unified hierarchy documentation cgroup: require write perm on common ancestor when moving processes on the default hierarchy cgroup: separate out cgroup_procs_write_permission() from __cgroup_procs_write() kernfs: make kernfs_get_inode() public MAINTAINERS: add a cgroup core co-maintainer cgroup: fix uninitialised iterator in for_each_subsys_which cgroup: replace explicit ss_mask checking with for_each_subsys_which cgroup: use bitmask to filter for_each_subsys cgroup: add seq_file forward declaration for struct cftype cgroup: simplify threadgroup locking sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem sched, cgroup: reorganize threadgroup locking cgroup: switch to unsigned long for bitmasks cgroup: reorganize include/linux/cgroup.h cgroup: separate out include/linux/cgroup-defs.h cgroup: fix some comment typos
| * | | sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsemTejun Heo2015-05-261-0/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cgroup side of threadgroup locking uses signal_struct->group_rwsem to synchronize against threadgroup changes. This per-process rwsem adds small overhead to thread creation, exit and exec paths, forces cgroup code paths to do lock-verify-unlock-retry dance in a couple places and makes it impossible to atomically perform operations across multiple processes. This patch replaces signal_struct->group_rwsem with a global percpu_rwsem cgroup_threadgroup_rwsem which is cheaper on the reader side and contained in cgroups proper. This patch converts one-to-one. This does make writer side heavier and lower the granularity; however, cgroup process migration is a fairly cold path, we do want to optimize thread operations over it and cgroup migration operations don't take enough time for the lower granularity to matter. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
* | | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2015-06-261-0/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge second patchbomb from Andrew Morton: - most of the rest of MM - lots of misc things - procfs updates - printk feature work - updates to get_maintainer, MAINTAINERS, checkpatch - lib/ updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits) exit,stats: /* obey this comment */ coredump: add __printf attribute to cn_*printf functions coredump: use from_kuid/kgid when formatting corename fs/reiserfs: remove unneeded cast NILFS2: support NFSv2 export fs/befs/btree.c: remove unneeded initializations fs/minix: remove unneeded cast init/do_mounts.c: add create_dev() failure log kasan: remove duplicate definition of the macro KASAN_FREE_PAGE fs/efs: femove unneeded cast checkpatch: emit "NOTE: <types>" message only once after multiple files checkpatch: emit an error when there's a diff in a changelog checkpatch: validate MODULE_LICENSE content checkpatch: add multi-line handling for PREFER_ETHER_ADDR_COPY checkpatch: suggest using eth_zero_addr() and eth_broadcast_addr() checkpatch: fix processing of MEMSET issues checkpatch: suggest using ether_addr_equal*() checkpatch: avoid NOT_UNIFIED_DIFF errors on cover-letter.patch files checkpatch: remove local from codespell path checkpatch: add --showfile to allow input via pipe to show filenames ...
| * | | fs, proc: introduce CONFIG_PROC_CHILDRENIago López Galeiras2015-06-251-0/+1
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 818411616baf ("fs, proc: introduce /proc/<pid>/task/<tid>/children entry") introduced the children entry for checkpoint restore and the file is only available on kernels configured with CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS) because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE. However, the children proc file is useful outside of checkpoint restore. I would like to use it in rkt. The rkt process exec() another program it does not control, and that other program will fork()+exec() a child process. I would like to find the pid of the child process from an external tool without iterating in /proc over all processes to find which one has a parent pid equal to rkt. This commit introduces CONFIG_PROC_CHILDREN and makes CONFIG_CHECKPOINT_RESTORE select it. This allows enabling /proc/<pid>/task/<tid>/children without needing to enable CONFIG_CHECKPOINT_RESTORE and CONFIG_EXPERT. Alban tested that /proc/<pid>/task/<tid>/children is present when the kernel is configured with CONFIG_PROC_CHILDREN=y but without CONFIG_CHECKPOINT_RESTORE Signed-off-by: Iago López Galeiras <iago@endocode.com> Tested-by: Alban Crequy <alban@endocode.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Djalal Harouni <djalal@endocode.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-blockLinus Torvalds2015-06-251-0/+5
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull cgroup writeback support from Jens Axboe: "This is the big pull request for adding cgroup writeback support. This code has been in development for a long time, and it has been simmering in for-next for a good chunk of this cycle too. This is one of those problems that has been talked about for at least half a decade, finally there's a solution and code to go with it. Also see last weeks writeup on LWN: http://lwn.net/Articles/648292/" * 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits) writeback, blkio: add documentation for cgroup writeback support vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB writeback: do foreign inode detection iff cgroup writeback is enabled v9fs: fix error handling in v9fs_session_init() bdi: fix wrong error return value in cgwb_create() buffer: remove unusued 'ret' variable writeback: disassociate inodes from dying bdi_writebacks writeback: implement foreign cgroup inode bdi_writeback switching writeback: add lockdep annotation to inode_to_wb() writeback: use unlocked_inode_to_wb transaction in inode_congested() writeback: implement unlocked_inode_to_wb transaction and use it for stat updates writeback: implement [locked_]inode_to_wb_and_lock_list() writeback: implement foreign cgroup inode detection writeback: make writeback_control track the inode being written back writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb() mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use writeback: implement memcg writeback domain based throttling writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes writeback: implement memcg wb_domain writeback: update wb_over_bg_thresh() to use wb_domain aware operations ...
| * | writeback: add {CONFIG|BDI_CAP|FS}_CGROUP_WRITEBACKTejun Heo2015-06-021-0/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup writeback requires support from both bdi and filesystem sides. Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by default. Also, define CONFIG_CGROUP_WRITEBACK which is enabled if both MEMCG and BLK_CGROUP are enabled. inode_cgwb_enabled() which determines whether a given inode's both bdi and fs support cgroup writeback is added. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-30 12:38:58 +0000