On Mon, Jun 13, 2022 at 09:58:21AM +0200, Greg KH wrote:
On Tue, Jun 07, 2022 at 01:10:36PM -0700, Leah Rumancik wrote:
From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb ]
The nfsd_file nf_rwsem is currently being used to separate file write and commit instances to ensure that we catch errors and apply them to the correct write/commit. We can improve scalability at the expense of a little accuracy (some extra false positives) by replacing the nf_rwsem with more careful use of the errseq_t mechanism to track errors across the different operations.
[Leah: This patch is for 5.10. 5011af4c698a ("nfsd: Fix stable writes") introduced a 75% performance regression on parallel random write workloads. With this commit, the performance is restored to 90% of what it was prior to 5011af4c698a. The changes to the fsync for asynchronous copies were not included in this backport version as the fsync was not added until 5.14 (eac0b17a77fb).]
Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Leah Rumancik leah.rumancik@gmail.com [ cel: rebased on zero-verifier fix ]
fs/nfsd/filecache.c | 1 - fs/nfsd/filecache.h | 1 - fs/nfsd/nfs4proc.c | 7 ++++--- fs/nfsd/vfs.c | 40 +++++++++++++++------------------------- 4 files changed, 19 insertions(+), 30 deletions(-)
What about 5.15? We can't take this patch for 5.10 only as if you upgrade to 5.15 you would have a regression. Can you provide a version for that tree so that I can then apply this one too?
thanks,
greg k-h
Just sent the 5.15 version. The upstream commit (555dbf1a9aac6d3150c8b52fa35f768a692f4eeb) actually applies cleanly on 5.15 so you can pull that or the version I just sent with the justification for backporting. After applying this commit to 5.15, I confirmed there was no peformance regression.
Best, Leah