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authorRoger Pau Monne <roger.pau@citrix.com>2013-04-17 20:18:56 +0200
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-04-18 09:29:22 -0400
commitc6cc142dac52e62e1e8a2aff5de1300202b96c66 (patch)
tree6123fb46fd4f4e3c8460852c9b215edc7a1f1c7a /Documentation
parentc1a15d08f497150a91ba4e61bab54b8f5c8b49b9 (diff)
downloadlinux-c6cc142dac52e62e1e8a2aff5de1300202b96c66.tar.gz
linux-c6cc142dac52e62e1e8a2aff5de1300202b96c66.tar.xz
xen-blkback: use balloon pages for all mappings
Using balloon pages for all granted pages allows us to simplify the logic in blkback, especially in the xen_blkbk_map function, since now we can decide if we want to map a grant persistently or not after we have actually mapped it. This could not be done before because persistent grants used ballooned pages, whereas non-persistent grants used pages from the kernel. This patch also introduces several changes, the first one is that the list of free pages is no longer global, now each blkback instance has it's own list of free pages that can be used to map grants. Also, a run time parameter (max_buffer_pages) has been added in order to tune the maximum number of free pages each blkback instance will keep in it's buffer. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: xen-devel@lists.xen.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/stable/sysfs-bus-xen-backend8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-bus-xen-backend b/Documentation/ABI/stable/sysfs-bus-xen-backend
index 3d5951c8bf5f..e04afe0cca99 100644
--- a/Documentation/ABI/stable/sysfs-bus-xen-backend
+++ b/Documentation/ABI/stable/sysfs-bus-xen-backend
@@ -73,3 +73,11 @@ KernelVersion: 3.0
Contact: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Description:
Number of sectors written by the frontend.
+
+What: /sys/module/xen_blkback/parameters/max_buffer_pages
+Date: March 2013
+KernelVersion: 3.10
+Contact: Roger Pau Monné <roger.pau@citrix.com>
+Description:
+ Maximum number of free pages to keep in each block
+ backend buffer.