On Thu, Jun 17, 2010 at 11:07:30AM -0500, James Bottomley wrote: > On Thu, 2010-06-17 at 18:00 +0200, Christof Schmitt wrote: > > On Wed, Jun 16, 2010 at 03:50:59PM -0500, James Bottomley wrote: > > > Given that we're under two months out, I thought it would be time to > > > post a summary of the topics we've collected so far (Nick will post the > > > MM summit ones later). Look this over, and if there's anything missing, > > > propose it ... or if you have cross Storage/FS/MM topics, post them too. > > > > > > Oh, and since we're not the most organised bunch, if you posted a topic > > > and don't see it in the list, please resend ... we probably lost it in > > > an email shuffle. > > > > > > Current Filesystem Topics: > > > > > > Alex Elder Upstream maintainer for XFS, general discussion on FS/IO > > > Aneesh Kumar Rich-acl patches which work better with NFSv4 acl and CIFS acl > > > Anshul Madan reflink for NFS > > > Chuck Lever NFS/IPV6 and NFS O_DIRECT, Wu's read-ahead work, vitro perf tools > > > Eric Sandeen Advances in testing, TRIM/DISCARD/Alignment, writeback sanity > > > James Lentini reflink for NFS > > > Jan Kara Discuss/drive sanity review of writeback and general ext*/jbd > > > Michael Rubin Writeback scaling > > > Sage Weil Statlite, generic interface for describing file striping for distributed FS, VFS scalability > > > Al Viro Sorting out d_revalidate and other dcache issues > > > Coly Li directory/large file scalability > > > Sorin Faibish Cache writeback discussion > > > > > > Current Storage Topics: > > > > > > Eric Seppanen Next generation SSDs, performance implications on Linux I/O > > > Boaz Harrosh PNFS performance considerations, bio_list based/async raidN for generic use; stable pages for I/O > > > FUJITA Tomonori SCSI target mode, iSCSI, block layer SG (bsg), sg, IOMMU, DMA issues > > > Hannes Reinecke libfc/multipath/error handing > > > James Smart FCOE proposal for rework of the FC sysfs tree, work with Hannes on other transport/SCSI subsystem topics > > > Jeff Moyer IO scheduler > > > Joel Becker SAN management plugin > > > Martin Petersen Updates on DIF/DIX, TRIM/DISCARD/UNMAP, generic support for WRITE_SAME > > > > > > Plus some MM summit ones which Nick will summarise. > > [...] > > > > What about the topic "Stable pages while IO"? > > http://www.spinics.net/lists/linux-scsi/msg44074.html > > > > Was it lost during the e-mail shuffle or will it be part of the MM topics? > > It's actually listed under 'dma issues' ... but there's really been no > satisfactory resolution or discussion of how one might be achieved. > Most filesystems rely on modifications to in-flight pages for efficiency > and copying every fs I/O page would be horrendous both for performance > and memory consumption. Nor has there really been an indication that > it's a serious issue. The two sufferers are DIF and iSCSI checksum. > The latter generates the checksum late enough that it can just discard > incorrect pages ... the former might need simply to turn off DIF for > everything other than DIRECT IO. It is a serious problem when using DIF, so turning off this feature or only using XFS and direct i/o does not sound very satisfying. But then i also see the points that have been discussed and that there is no simple solution. Christof -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>