On Mon, Jul 28, 2025 at 09:53:45AM -0400, Chuck Lever wrote: > On 7/28/25 9:51 AM, Mike Snitzer wrote: > > On Sun, Jul 27, 2025 at 12:16:04PM -0400, Chuck Lever wrote: > >> From: Chuck Lever <chuck.lever@xxxxxxxxxx> > >> > >> On Thu, 24 Jul 2025 15:30:49 -0400, Mike Snitzer wrote: > >>> Some workloads benefit from NFSD avoiding the page cache, particularly > >>> those with a working set that is significantly larger than available > >>> system memory. This patchset introduces _optional_ support to > >>> configure the use of O_DIRECT or DONTCACHE for NFSD's READ and WRITE > >>> support. The NFSD default to use page cache is left unchanged. > >>> > >>> The performance win associated with using NFSD DIRECT was previously > >>> summarized here: > >>> https://lore.kernel.org/linux-nfs/aEslwqa9iMeZjjlV@xxxxxxxxxx/ > >>> This picture offers a nice summary of performance gains: > >>> https://original.art/NFSD_direct_vs_buffered_IO.jpg > >>> > >>> [...] > >> > >> Applied to nfsd-testing, thanks! > >> > >> [01/13] NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support > >> commit: af157e09634a113da83d8ac5fff541f9e06ad653 > > > >> [05/13] NFSD: filecache: only get DIO alignment attrs if NFSD_IO_DIRECT enabled > >> commit: af157e09634a113da83d8ac5fff541f9e06ad653 > > > > I noticed you folded these, unfortunately that isn't bisect safe > > unless you pull these fs/nfsd/nfsd.h changes to the front too: > > > > git diff f76b72e4908c556021d94bdeca86fffce430c791^..a45da44bb6bade1dfef569c792ae2ee6507f4724 -- fs/nfsd/nfsd.h > > > > diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h > > index 1cd0bed57bc2..fe935b4cda53 100644 > > --- a/fs/nfsd/nfsd.h > > +++ b/fs/nfsd/nfsd.h > > @@ -153,6 +153,16 @@ static inline void nfsd_debugfs_exit(void) {} > > > > extern bool nfsd_disable_splice_read __read_mostly; > > > > +enum { > > + NFSD_IO_UNSPECIFIED = 0, > > + NFSD_IO_BUFFERED, > > + NFSD_IO_DONTCACHE, > > + NFSD_IO_DIRECT, > > +}; > > + > > +extern u64 nfsd_io_cache_read __read_mostly; > > +extern u64 nfsd_io_cache_write __read_mostly; > > + > > extern int nfsd_max_blksize; > > > > static inline int nfsd_v4client(struct svc_rqst *rq) > > > >> [02/13] NFSD: pass nfsd_file to nfsd_iter_read() > >> commit: 63a534c8b18642dc27318e08b77952c4d7f55628 > >> [03/13] NFSD: add io_cache_read controls to debugfs interface > >> commit: f76b72e4908c556021d94bdeca86fffce430c791 > >> [04/13] NFSD: add io_cache_write controls to debugfs interface > >> commit: a45da44bb6bade1dfef569c792ae2ee6507f4724 > > > >> [06/13] NFSD: issue READs using O_DIRECT even if IO is misaligned > >> commit: 6d80efb3cb6f9817bedfa460e9ddf56a916caf2f > > > > Thanks! > > Mike > > That's what I get for compile-testing first before squashing. It happens, you also need this from vfs.c: diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 9bbc97aebbea..a7a587736a22 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -49,6 +49,8 @@ #define NFSDDBG_FACILITY NFSDDBG_FILEOP bool nfsd_disable_splice_read __read_mostly; +u64 nfsd_io_cache_read __read_mostly; +u64 nfsd_io_cache_write __read_mostly; /**
