| Message ID | 20230726102603.155522-1-hao.xu@linux.dev (mailing list archive) |
|---|---|
| Headers | show |
| Series | io_uring lseek | expand |
On Wed, Jul 26, 2023 at 06:25:56PM +0800, Hao Xu wrote: > From: Hao Xu <howeyxu@tencent.com> > > This series adds lseek for io_uring, the motivation to import this > syscall is in previous io_uring getdents patchset, we lack a way to > rewind the file cursor when it goes to the end of file. Another reason > is lseek is a common syscall, it's good for coding consistency when > users use io_uring as their main loop. While I understand this it is a time consuming review to make sure things work correctly. So before we get this thing going we better get getdents correct first. > > Patch 1 is code clean for iomap > Patch 2 adds IOMAP_NOWAIT logic for iomap lseek > Patch 3 adds a nowait parameter to for IOMAP_NOWAIT control > Patch 4 adds llseek_nowait() for file_operations so that specific > filesystem can implement it for nowait lseek > Patch 5 adds llseek_nowait() implementation for xfs > Patch 6 adds a new vfs wrapper for io_uring use > Patch 7 is the main io_uring lseek implementation > > Note, this series depends on the previous io_uring getdents series. > > This is marked RFC since there is (at least) an issue to be discussed: > The work in this series is mainly to reslove a problem that the current > llseek() in struct file_operations doesn't have a place to deliver > nowait info, and adding an argument to it results in update for llseek > implementation of all filesystems (35 functions), so here I introduce > a new llseek_nowait() as a workaround. My intuition would be to update all filesystems. Adding new inode operations always starts as a temporary thing and then we live with two different methods for the next years or possibly forever. But it'd be good to hear what others think.
On 7/26/23 18:25, Hao Xu wrote: > From: Hao Xu <howeyxu@tencent.com> > > This series adds lseek for io_uring, the motivation to import this > syscall is in previous io_uring getdents patchset, we lack a way to > rewind the file cursor when it goes to the end of file. Another reason > is lseek is a common syscall, it's good for coding consistency when > users use io_uring as their main loop. > > Patch 1 is code clean for iomap > Patch 2 adds IOMAP_NOWAIT logic for iomap lseek > Patch 3 adds a nowait parameter to for IOMAP_NOWAIT control > Patch 4 adds llseek_nowait() for file_operations so that specific > filesystem can implement it for nowait lseek > Patch 5 adds llseek_nowait() implementation for xfs > Patch 6 adds a new vfs wrapper for io_uring use > Patch 7 is the main io_uring lseek implementation > > Note, this series depends on the previous io_uring getdents series. > > This is marked RFC since there is (at least) an issue to be discussed: > The work in this series is mainly to reslove a problem that the current > llseek() in struct file_operations doesn't have a place to deliver > nowait info, and adding an argument to it results in update for llseek > implementation of all filesystems (35 functions), so here I introduce > a new llseek_nowait() as a workaround. > > For performance, it has about 20%~30% improvement on iops. > The test program is just like the one for io_uring getdents, here is the > link to it: https://github.com/HowHsu/liburing/blob/llseek/test/lseek.c > - Each test runs about 30000 async requests/sync syscalls > - Each test runs 100 times and get the average value. > - offset is randomly generated value > - the file is a 1M all zero file > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_SET, offset: 334772 > Average of sync : 0.012300650000000002 > Average of iouring : 0.008528009999999999 > 30.67% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_CUR, offset: 389292 > Average of sync : 0.012736129999999995 > Average of iouring : 0.00928725 > 27.08% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_END, offset: 281141 > Average of sync : 0.01221595 > Average of iouring : 0.008442890000000003 > 30.89% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_DATA, offset: 931103 > Average of sync : 0.015496230000000005 > Average of iouring : 0.012341509999999998 > 20.36% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_HOLE, offset: 430194 > Average of sync : 0.01555663000000001 > Average of iouring : 0.012064940000000003 > 22.45% > > > Hao Xu (7): > iomap: merge iomap_seek_hole() and iomap_seek_data() > xfs: add nowait support for xfs_seek_iomap_begin() > add nowait parameter for iomap_seek() > add llseek_nowait() for struct file_operations > add llseek_nowait support for xfs > add vfs_lseek_nowait() > add lseek for io_uring > > fs/ext4/file.c | 9 ++--- > fs/gfs2/inode.c | 4 +-- > fs/iomap/seek.c | 42 ++++++----------------- > fs/read_write.c | 18 ++++++++++ > fs/xfs/xfs_file.c | 34 ++++++++++++++++--- > fs/xfs/xfs_iomap.c | 4 ++- > include/linux/fs.h | 4 +++ > include/linux/iomap.h | 6 ++-- > include/uapi/linux/io_uring.h | 1 + > io_uring/fs.c | 63 +++++++++++++++++++++++++++++++++++ > io_uring/fs.h | 3 ++ > io_uring/opdef.c | 8 +++++ > 12 files changed, 145 insertions(+), 51 deletions(-) > > > base-commit: 4a4b046082eca8ae90b654d772fccc30e9f23f4d Hi folks, I'll leave this patchset here before the io_uring getdents is merged, then come back and update this one. Thanks, Hao
From: Hao Xu <howeyxu@tencent.com> This series adds lseek for io_uring, the motivation to import this syscall is in previous io_uring getdents patchset, we lack a way to rewind the file cursor when it goes to the end of file. Another reason is lseek is a common syscall, it's good for coding consistency when users use io_uring as their main loop. Patch 1 is code clean for iomap Patch 2 adds IOMAP_NOWAIT logic for iomap lseek Patch 3 adds a nowait parameter to for IOMAP_NOWAIT control Patch 4 adds llseek_nowait() for file_operations so that specific filesystem can implement it for nowait lseek Patch 5 adds llseek_nowait() implementation for xfs Patch 6 adds a new vfs wrapper for io_uring use Patch 7 is the main io_uring lseek implementation Note, this series depends on the previous io_uring getdents series. This is marked RFC since there is (at least) an issue to be discussed: The work in this series is mainly to reslove a problem that the current llseek() in struct file_operations doesn't have a place to deliver nowait info, and adding an argument to it results in update for llseek implementation of all filesystems (35 functions), so here I introduce a new llseek_nowait() as a workaround. For performance, it has about 20%~30% improvement on iops. The test program is just like the one for io_uring getdents, here is the link to it: https://github.com/HowHsu/liburing/blob/llseek/test/lseek.c - Each test runs about 30000 async requests/sync syscalls - Each test runs 100 times and get the average value. - offset is randomly generated value - the file is a 1M all zero file [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_SET, offset: 334772 Average of sync : 0.012300650000000002 Average of iouring : 0.008528009999999999 30.67% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_CUR, offset: 389292 Average of sync : 0.012736129999999995 Average of iouring : 0.00928725 27.08% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_END, offset: 281141 Average of sync : 0.01221595 Average of iouring : 0.008442890000000003 30.89% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_DATA, offset: 931103 Average of sync : 0.015496230000000005 Average of iouring : 0.012341509999999998 20.36% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_HOLE, offset: 430194 Average of sync : 0.01555663000000001 Average of iouring : 0.012064940000000003 22.45% Hao Xu (7): iomap: merge iomap_seek_hole() and iomap_seek_data() xfs: add nowait support for xfs_seek_iomap_begin() add nowait parameter for iomap_seek() add llseek_nowait() for struct file_operations add llseek_nowait support for xfs add vfs_lseek_nowait() add lseek for io_uring fs/ext4/file.c | 9 ++--- fs/gfs2/inode.c | 4 +-- fs/iomap/seek.c | 42 ++++++----------------- fs/read_write.c | 18 ++++++++++ fs/xfs/xfs_file.c | 34 ++++++++++++++++--- fs/xfs/xfs_iomap.c | 4 ++- include/linux/fs.h | 4 +++ include/linux/iomap.h | 6 ++-- include/uapi/linux/io_uring.h | 1 + io_uring/fs.c | 63 +++++++++++++++++++++++++++++++++++ io_uring/fs.h | 3 ++ io_uring/opdef.c | 8 +++++ 12 files changed, 145 insertions(+), 51 deletions(-) base-commit: 4a4b046082eca8ae90b654d772fccc30e9f23f4d