Bug 865305 – fuse: backport scatter-gather direct IO [rhel-6.3.z]

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Bug 865305 - fuse: backport scatter-gather direct IO [rhel-6.3.z]

Summary:	fuse: backport scatter-gather direct IO [rhel-6.3.z]

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 6
Classification:	Red Hat
Component:	kernel (Show other bugs)
Sub Component:
Version:	6.4
Hardware:	Unspecified Unspecified

Priority	urgent Severity high
Target Milestone:	rc
Target Release:	---
Assigned To:	Frantisek Hrbata
QA Contact:	Red Hat Kernel QE team
Docs Contact:

URL:
Whiteboard:
Keywords:	ZStream

Depends On:	858850
Blocks:
	Show dependency tree / graph

Reported:	2012-10-11 04:00 EDT by RHEL Product and Program Management
Modified:	2013-02-07 08:20 EST (History)
CC List:	15 users (show)

See Also:
Fixed In Version:	kernel-2.6.32-279.22.1.el6
Doc Type:	Bug Fix
Doc Text:	Filesystem in Userspace (FUSE) did not implement scatter-gather direct I/O optimally. Consequently, the kernel had to process an extensive number of FUSE requests, which had a negative impact on system performance. This update applies a set of patches which improves internal request management for other features, such as readahead. FUSE direct I/O overhead has been significantly reduced to minimize negative effects on system performance.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2013-02-05 14:56:12 EST
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2013:0223	normal	SHIPPED_LIVE	Moderate: kernel security and bug fix update	2013-02-05 19:52:09 EST

Groups: None (edit)

Description RHEL Product and Program Management 2012-10-11 04:00:26 EDT

This bug has been copied from bug #858850 and has been proposed
to be backported to 6.3 z-stream (EUS).

Comment 8 Ben England 2013-01-21 10:06:21 EST

Monson,

see comment in https://bugzilla.redhat.com/show_bug.cgi?id=858850#c18 which describes how to get the test program and data.  I didn't realize you had a separate bz for this.  I think I can test the kernel for you now that I know where to find it.  You can too if you have 10-GbE and some storage with throughput similar to 10-GbE.  We really want this patch because it makes a huge difference, see the article at 

http://perf1.perf.lab.eng.bos.redhat.com/bengland/laptop/matte/virt/rhev-rhs-brief/rhev-rhs-single-host-perfbrief-v1.0.odt

Best Regards, -ben

Comment 10 Ben England 2013-01-22 22:51:27 EST

so which rhel6.4 kernel should I test with?  We'll try the RHEL6.3 kernel ASAP.  I pulled RPMs in #c9 from Brew.

Comment 11 Monson Shao 2013-01-23 00:32:58 EST

(In reply to comment #10)
> so which rhel6.4 kernel should I test with?  We'll try the RHEL6.3 kernel
> ASAP.  I pulled RPMs in #c9 from Brew.

The rhel6.4 kernel has been tested in Bug 858850 .
So what you only need to do is pasting rhel6.3 kernel test result here, and I will do the rest. Thanks.

Comment 12 Ben England 2013-01-23 23:39:59 EST

I retested with above kernel 2.6.32-279.22.1.el6.x86_64 and 2.6.32-279.el6.x86_64 (RHEL6.3) and again I see a huge increase in throughput particularly with iozone reads from 1 or more guests inside the KVM host.  Data and graphs are at:

http://perf1.perf.lab.eng.bos.redhat.com/bengland/public/rhs/virt/sg-patch-retest-2013-01-21.ods

Let me know when this patch can be obtained via RHN updates to RHEL6.3.

Comment 15 errata-xmlrpc 2013-02-05 14:56:12 EST

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2013-0223.html

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