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| author | Zhou Chengming <zhouchengming1@huawei.com> | 2017-03-28 21:10:35 +0800 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2017-03-30 10:41:38 +0200 |
| commit | 72f04b50d61c81a2cc3065d3b973e83827760515 (patch) | |
| tree | 41c7a9716078c4aef3947be131d1c308094de97a /kernel/livepatch | |
| parent | c1ae3cfa0e89fa1a7ecc4c99031f5e9ae99d9201 (diff) | |
| download | linux-0-day-72f04b50d61c81a2cc3065d3b973e83827760515.tar.gz linux-0-day-72f04b50d61c81a2cc3065d3b973e83827760515.tar.xz | |
livepatch: Reduce the time of finding module symbols
It's reported that the time of insmoding a klp.ko for one of our
out-tree modules is too long.
~ time sudo insmod klp.ko
real 0m23.799s
user 0m0.036s
sys 0m21.256s
Then we found the reason: our out-tree module used a lot of static local
variables, so klp.ko has a lot of relocation records which reference the
module. Then for each such entry klp_find_object_symbol() is called to
resolve it, but this function uses the interface kallsyms_on_each_symbol()
even for finding module symbols, so will waste a lot of time on walking
through vmlinux kallsyms table many times.
This patch changes it to use module_kallsyms_on_each_symbol() for modules
symbols. After we apply this patch, the sys time reduced dramatically.
~ time sudo insmod klp.ko
real 0m1.007s
user 0m0.032s
sys 0m0.924s
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'kernel/livepatch')
| -rw-r--r-- | kernel/livepatch/core.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index af4643873e717..b4b8bb012a93c 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -182,7 +182,10 @@ static int klp_find_object_symbol(const char *objname, const char *name, }; mutex_lock(&module_mutex); - kallsyms_on_each_symbol(klp_find_callback, &args); + if (objname) + module_kallsyms_on_each_symbol(klp_find_callback, &args); + else + kallsyms_on_each_symbol(klp_find_callback, &args); mutex_unlock(&module_mutex); /* |