diff options
| author | John Johansen <john.johansen@canonical.com> | 2010-09-15 10:28:20 -0700 |
|---|---|---|
| committer | John Rigby <john.rigby@linaro.org> | 2012-06-21 21:07:22 -0600 |
| commit | 0fa10147143e9c3b2b0f4239b0b639a6a393d674 (patch) | |
| tree | 139742fb73d215f0aef4c7f6142e68c6df015c6c /include | |
| parent | 7de9bedb17b2fa8929619dc37cbfd0f3dfa09eb6 (diff) | |
UBUNTU: SAUCE: Improve Amazon EBS performance for EC2
OriginalAuthor: Amazona from Ben Howard <behoward@amazon.com>
BugLink: http://bugs.launchpad.net/bugs/634316
The pv-ops kernel suffers from poor performance when using Amazon's
Elastic block storage (EBS). This patch from Amazon improves pv-ops
kernel performance, and has not exhibited any regressions.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/xen/interface/io/blkif.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index ee338bfde18..31063bd1b69 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -168,6 +168,18 @@ struct blkif_response { DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response); +/* + * Maximum number of pages used for a blkif ring + * max-ring-pages advertised by blkback to blkfront may be lowered at blkback + * mod load time. Load time param set to default. + */ +#define BLKIF_MAX_NUM_RING_PAGES 16 +#define BLKIF_MAX_NUM_RING_PAGES_DFLT 4 +#if BLKIF_MAX_NUM_RING_PAGES < BLKIF_MAX_NUM_RING_PAGES_DFLT +#undef BLKIF_MAX_NUM_RING_PAGES_DFLT +#define BLKIF_MAX_NUM_RING_PAGES_DFLT BLKIF_MAX_NUM_RING_PAGES +#endif + #define VDISK_CDROM 0x1 #define VDISK_REMOVABLE 0x2 #define VDISK_READONLY 0x4 |