b=21137 sles11 with 1.8 is slower than 1.6 sles10 for O_DIRECT single file IOR writes

 Fix __bio_add_page() in order to prevent IO split on some drivers.

 i=andreas.dilger
 i=sheng.yang

 This patch comes from the kernel commit

Gitweb:     http://git.kernel.org/linus/8a78362c4eefc1deddbefe2c7f38aabbc2429d6b
Commit:     8a78362c4eefc1deddbefe2c7f38aabbc2429d6b
Parent:     086fa5ff0854c676ec333760f4c0154b3b242616
Author:     Martin K. Petersen <martin.petersen@oracle.com>
AuthorDate: Fri Feb 26 00:20:39 2010 -0500
Committer:  Jens Axboe <jens.axboe@oracle.com>
CommitDate: Fri Feb 26 13:58:08 2010 +0100

    block: Consolidate phys_segment and hw_segment limits

    Except for SCSI no device drivers distinguish between physical and
    hardware segment limits.  Consolidate the two into a single segment
    limit.

diff --git a/lustre/kernel_patches/patches/bio_add_page.patch b/lustre/kernel_patches/patches/bio_add_page.patch
new file mode 100644 (file)
index 0000000..4a9a311
--- /dev/null
+++ b/lustre/kernel_patches/patches/bio_add_page.patch
@@ -0,0 +1,12 @@
+--- linux-2.6.32.13-0.5.orig/fs/bio.c  2010-08-13 04:22:33.000000000 -0400
++++ linux-2.6.32.13-0.5/fs/bio.c       2010-09-08 15:35:44.000000000 -0400
+@@ -575,8 +575,7 @@ static int __bio_add_page(struct request
+        * make this too complex.
+        */
+ 
+-      while (bio->bi_phys_segments >= queue_max_phys_segments(q)
+-             || bio->bi_phys_segments >= queue_max_hw_segments(q)) {
++      while (bio->bi_phys_segments >= queue_max_phys_segments(q)) {
+ 
+               if (retried_segments)
+                       return 0;

diff --git a/lustre/kernel_patches/series/2.6-sles11.series b/lustre/kernel_patches/series/2.6-sles11.series
index 071c5be..ca26eaf 100644 (file)
--- a/lustre/kernel_patches/series/2.6-sles11.series
+++ b/lustre/kernel_patches/series/2.6-sles11.series
@@ -9,3 +9,4 @@ md-mmp-unplug-dev-sles11.patch
 quota-support-64-bit-quota-format.patch
 jbd2-jcberr-2.6-sles11.patch
 jbd2-commit-timer-no-jiffies-rounding.diff
+bio_add_page.patch