| Message ID | 20210209023008.76263-3-axboe@kernel.dk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Improve IOCB_NOWAIT O_DIRECT reads | expand |
On Mon, Feb 08, 2021 at 07:30:07PM -0700, Jens Axboe wrote: > For the generic page cache read helper, use the better variant of checking > for the need to call filemap_write_and_wait_range() when doing O_DIRECT > reads. This avoids falling back to the slow path for IOCB_NOWAIT, if there > are no pages to wait for (or write out). > > Signed-off-by: Jens Axboe <axboe@kernel.dk> > --- > mm/filemap.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 6a58d50fbd31..c80acb80e8f7 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2643,8 +2643,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) > > size = i_size_read(inode); > if (iocb->ki_flags & IOCB_NOWAIT) { > - if (filemap_range_has_page(mapping, iocb->ki_pos, > - iocb->ki_pos + count - 1)) > + if (filemap_range_needs_writeback(mapping, iocb->ki_pos, > + iocb->ki_pos + count - 1)) Please avoid the overy long line, which is trivial to do by using the normal two tab indent for the continuation.
On 2/9/21 12:48 AM, Christoph Hellwig wrote: > On Mon, Feb 08, 2021 at 07:30:07PM -0700, Jens Axboe wrote: >> For the generic page cache read helper, use the better variant of checking >> for the need to call filemap_write_and_wait_range() when doing O_DIRECT >> reads. This avoids falling back to the slow path for IOCB_NOWAIT, if there >> are no pages to wait for (or write out). >> >> Signed-off-by: Jens Axboe <axboe@kernel.dk> >> --- >> mm/filemap.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/mm/filemap.c b/mm/filemap.c >> index 6a58d50fbd31..c80acb80e8f7 100644 >> --- a/mm/filemap.c >> +++ b/mm/filemap.c >> @@ -2643,8 +2643,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) >> >> size = i_size_read(inode); >> if (iocb->ki_flags & IOCB_NOWAIT) { >> - if (filemap_range_has_page(mapping, iocb->ki_pos, >> - iocb->ki_pos + count - 1)) >> + if (filemap_range_needs_writeback(mapping, iocb->ki_pos, >> + iocb->ki_pos + count - 1)) > > Please avoid the overy long line, which is trivial to do by using the > normal two tab indent for the continuation. Sure, fixed.
diff --git a/mm/filemap.c b/mm/filemap.c index 6a58d50fbd31..c80acb80e8f7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2643,8 +2643,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) size = i_size_read(inode); if (iocb->ki_flags & IOCB_NOWAIT) { - if (filemap_range_has_page(mapping, iocb->ki_pos, - iocb->ki_pos + count - 1)) + if (filemap_range_needs_writeback(mapping, iocb->ki_pos, + iocb->ki_pos + count - 1)) return -EAGAIN; } else { retval = filemap_write_and_wait_range(mapping,
For the generic page cache read helper, use the better variant of checking for the need to call filemap_write_and_wait_range() when doing O_DIRECT reads. This avoids falling back to the slow path for IOCB_NOWAIT, if there are no pages to wait for (or write out). Signed-off-by: Jens Axboe <axboe@kernel.dk> --- mm/filemap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)