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| author | Ed Cashin <ecashin@coraid.com> | 2012-10-04 17:16:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-06 03:05:24 +0900 |
| commit | 3d5b06051cd5fa82c9a4285f7ce8650a0f0845ff (patch) | |
| tree | 66b62def9b84b9d274f2d6b3589635015f98c56d /drivers/block/aoe/aoeblk.c | |
| parent | a336d29870f8a1f8e5f10d9f1aa95531c4edeabe (diff) | |
| download | op-kernel-dev-3d5b06051cd5fa82c9a4285f7ce8650a0f0845ff.zip op-kernel-dev-3d5b06051cd5fa82c9a4285f7ce8650a0f0845ff.tar.gz | |
aoe: for performance support larger packet payloads
tAdd adds the ability to work with large packets composed of a number of
segments, using the scatter gather feature of the block layer (biovecs)
and the network layer (skb frag array). The motivation is the performance
gained by using a packet data payload greater than a page size and by
using the network card's scatter gather feature.
Users of the out-of-tree aoe driver already had these changes, but since
early 2011, they have complained of increased memory utilization and
higher CPU utilization during heavy writes.[1] The commit below appears
related, as it disables scatter gather on non-IP protocols inside the
harmonize_features function, even when the NIC supports sg.
commit f01a5236bd4b140198fbcc550f085e8361fd73fa
Author: Jesse Gross <jesse@nicira.com>
Date: Sun Jan 9 06:23:31 2011 +0000
net offloading: Generalize netif_get_vlan_features().
With that regression in place, transmits always linearize sg AoE packets,
but in-kernel users did not have this patch. Before 2.6.38, though, these
changes were working to allow sg to increase performance.
1. http://www.spinics.net/lists/linux-mm/msg15184.html
Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block/aoe/aoeblk.c')
| -rw-r--r-- | drivers/block/aoe/aoeblk.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index 321de7b..3a8f093 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -254,6 +254,7 @@ aoeblk_gdalloc(void *vp) { struct aoedev *d = vp; struct gendisk *gd; + enum { KB = 1024, MB = KB * KB, READ_AHEAD = MB, }; ulong flags; gd = alloc_disk(AOE_PARTITIONS); @@ -279,6 +280,8 @@ aoeblk_gdalloc(void *vp) if (bdi_init(&d->blkq->backing_dev_info)) goto err_blkq; spin_lock_irqsave(&d->lock, flags); + blk_queue_max_hw_sectors(d->blkq, BLK_DEF_MAX_SECTORS); + d->blkq->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE; gd->major = AOE_MAJOR; gd->first_minor = d->sysminor * AOE_PARTITIONS; gd->fops = &aoe_bdops; |
