| Message ID | 20191120050024.11161-2-riteshh@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ext4: Introducing ilock wrapper APIs & fixing i_rwsem scalablity prob. in DIO mixed-rw | expand |
On Wed 20-11-19 10:30:21, Ritesh Harjani wrote: > Apparently our current rwsem code doesn't like doing the trylock, then > lock for real scheme. So change our dax read/write methods to just do the > trylock for the RWF_NOWAIT case. > This seems to fix AIM7 regression in some scalable filesystems upto ~25% > in some cases. Claimed in commit 942491c9e6d6 ("xfs: fix AIM7 regression") > > Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/file.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/fs/ext4/file.c b/fs/ext4/file.c > index 6a7293a5cda2..977ac58dc718 100644 > --- a/fs/ext4/file.c > +++ b/fs/ext4/file.c > @@ -88,9 +88,10 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) > struct inode *inode = file_inode(iocb->ki_filp); > ssize_t ret; > > - if (!inode_trylock_shared(inode)) { > - if (iocb->ki_flags & IOCB_NOWAIT) > + if (iocb->ki_flags & IOCB_NOWAIT) { > + if (!inode_trylock_shared(inode)) > return -EAGAIN; > + } else { > inode_lock_shared(inode); > } > /* > @@ -487,9 +488,10 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) > bool extend = false; > struct inode *inode = file_inode(iocb->ki_filp); > > - if (!inode_trylock(inode)) { > - if (iocb->ki_flags & IOCB_NOWAIT) > + if (iocb->ki_flags & IOCB_NOWAIT) { > + if (!inode_trylock(inode)) > return -EAGAIN; > + } else { > inode_lock(inode); > } > > -- > 2.21.0 >
On Wed, Nov 20, 2019 at 10:30:21AM +0530, Ritesh Harjani wrote: > Apparently our current rwsem code doesn't like doing the trylock, then > lock for real scheme. So change our dax read/write methods to just do the > trylock for the RWF_NOWAIT case. > This seems to fix AIM7 regression in some scalable filesystems upto ~25% > in some cases. Claimed in commit 942491c9e6d6 ("xfs: fix AIM7 regression") > > Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> This looks OK to me. Feel free to add: Reviewed-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> /M
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 6a7293a5cda2..977ac58dc718 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -88,9 +88,10 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) struct inode *inode = file_inode(iocb->ki_filp); ssize_t ret; - if (!inode_trylock_shared(inode)) { - if (iocb->ki_flags & IOCB_NOWAIT) + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!inode_trylock_shared(inode)) return -EAGAIN; + } else { inode_lock_shared(inode); } /* @@ -487,9 +488,10 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) bool extend = false; struct inode *inode = file_inode(iocb->ki_filp); - if (!inode_trylock(inode)) { - if (iocb->ki_flags & IOCB_NOWAIT) + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!inode_trylock(inode)) return -EAGAIN; + } else { inode_lock(inode); }
Apparently our current rwsem code doesn't like doing the trylock, then lock for real scheme. So change our dax read/write methods to just do the trylock for the RWF_NOWAIT case. This seems to fix AIM7 regression in some scalable filesystems upto ~25% in some cases. Claimed in commit 942491c9e6d6 ("xfs: fix AIM7 regression") Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> --- fs/ext4/file.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)