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 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part URL: <http://lists.centos.org/pipermail/centos/attachments/20070223/4621ee90/attachment-0005.sig>