I am inquiring on the list if anybody knows if the latest plus kernel includes the fixes for MD RAID-1 where it didn't pass down the BIO_RW_SYNC flag on cloned bios.
This bug was discovered in December by the DRBD project and patches were posted by Lars Ellenberg from that project to the LKM which were then merged into the 2.6.19 kernel.
The bug causes severe performance penalties for applications that use the BIO_RW_SYNC flag on block requests.
The fix is a simple 2 to 4 line change where it ORs the sync flag on the cloned bios.
If it isn't in the plus kernel, how would one go about putting a request to have it included?
Thanks,
Ross S. W. Walker Information Systems Manager Medallion Financial, Corp. 437 Madison Avenue 38th Floor New York, NY 10022 Tel: (212) 328-2165 Fax: (212) 328-2125 WWW: http://www.medallion.com http://www.medallion.com
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On Fri, 2007-02-23 at 14:01 -0500, Ross S. W. Walker wrote:
I am inquiring on the list if anybody knows if the latest plus kernel includes the fixes for MD RAID-1 where it didn't pass down the BIO_RW_SYNC flag on cloned bios.
This bug was discovered in December by the DRBD project and patches were posted by Lars Ellenberg from that project to the LKM which were then merged into the 2.6.19 kernel.
The bug causes severe performance penalties for applications that use the BIO_RW_SYNC flag on block requests.
The fix is a simple 2 to 4 line change where it ORs the sync flag on the cloned bios.
If it isn't in the plus kernel, how would one go about putting a request to have it included?
Ross,
We don't normally include external patches in the CentOSPlus kernel ... just change options in the config file, however since we also do support DRBD and heartbeat in CentOS Extras I would be willing to try to make this happen in the Plus Kernel.
Have you been able to roll this patch in to the current Plus kernel?
Thanks, Johnny Hughes
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Johnny Hughes Sent: Friday, February 23, 2007 4:46 PM To: CentOS ML Subject: Re: [CentOS] Latest Plus Kernel include MD RAID-1 BIO_RW_SYNC patch?
On Fri, 2007-02-23 at 14:01 -0500, Ross S. W. Walker wrote:
I am inquiring on the list if anybody knows if the latest
plus kernel
includes the fixes for MD RAID-1 where it didn't pass down the BIO_RW_SYNC flag on cloned bios.
This bug was discovered in December by the DRBD project and
patches were
posted by Lars Ellenberg from that project to the LKM which
were then
merged into the 2.6.19 kernel.
The bug causes severe performance penalties for
applications that use
the BIO_RW_SYNC flag on block requests.
The fix is a simple 2 to 4 line change where it ORs the
sync flag on the
cloned bios.
If it isn't in the plus kernel, how would one go about
putting a request
to have it included?
Ross,
We don't normally include external patches in the CentOSPlus kernel ... just change options in the config file, however since we also do support DRBD and heartbeat in CentOS Extras I would be willing to try to make this happen in the Plus Kernel.
Have you been able to roll this patch in to the current Plus kernel?
I haven't tried yet to tell you the truth. I can give it a shot and if I get the patch as-is to work I can post it to... Which list should I use for that, is there a CentOS developers list?
-Ross
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On 2/23/07, Ross S. W. Walker rwalker@medallion.com wrote: <snippety>
I haven't tried yet to tell you the truth. I can give it a shot and if I get the patch as-is to work I can post it to... Which list should I use for that, is there a CentOS developers list?
Sure is -> http://lists.centos.org/mailman/listinfo/centos-devel
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Jim Perrin Sent: Friday, February 23, 2007 6:05 PM To: CentOS mailing list Subject: Re: [CentOS] Latest Plus Kernel include MD RAID-1 BIO_RW_SYNC patch?
On 2/23/07, Ross S. W. Walker rwalker@medallion.com wrote:
<snippety> > I haven't tried yet to tell you the truth. I can give it a shot and if I > get the patch as-is to work I can post it to... Which list should I use > for that, is there a CentOS developers list? >
Sure is -> http://lists.centos.org/mailman/listinfo/centos-devel
Right-o, thanks I'll post it there.
-Ross
______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.
-
Jim Perrin -
Johnny Hughes -
Ross S. W. Walker