From: Hao Xu <howeyxu@xxxxxxxxxxx> This series introduce getdents64 to io_uring, the code logic is similar with the snychronized version's. It first try nowait issue, and offload it to io-wq threads if the first try fails. Tested it with a liburing case: https://github.com/HowHsu/liburing/blob/getdents/test/getdents2.c The test is controlled by the below script[2] which runs getdents2.t 100 times and calulate the avg. The result show that io_uring version is about 3% faster: python3 run_getdents.py Average of sync: 0.1036849 Average of iouring: 0.1005568 (0.1036849-0.1005568)/0.1036849 = 3.017% note: [1] the number of getdents call/request in io_uring and normal sync version are made sure to be same beforehand. [2] run_getdents.py ```python3 import subprocess N = 100 sum = 0.0 args = ["/data/home/howeyxu/tmpdir", "sync"] for i in range(N): output = subprocess.check_output(["./liburing/test/getdents2.t"] + args) sum += float(output) average = sum / N print("Average of sync:", average) sum = 0.0 args = ["/data/home/howeyxu/tmpdir", "iouring"] for i in range(N): output = subprocess.check_output(["./liburing/test/getdents2.t"] + args) sum += float(output) average = sum / N print("Average of iouring:", average) ``` v3->v4: - add Dave's xfs nowait code and fix a deadlock problem, with some code style tweak. - disable fixed file to avoid a race problem for now - add a test program. v2->v3: - removed the kernfs patches - add f_pos_lock logic - remove the "reduce last EOF getdents try" optimization since Dominique reports that doesn't make difference - remove the rewind logic, I think the right way is to introduce lseek to io_uring not to patch this logic to getdents. - add Singed-off-by of Stefan Roesch for patch 1 since checkpatch complained that Co-developed-by someone should be accompanied with Signed-off-by same person, I can remove them if Stefan thinks that's not proper. Dominique Martinet (1): fs: split off vfs_getdents function of getdents64 syscall Hao Xu (4): vfs_getdents/struct dir_context: add flags field io_uring: add support for getdents xfs: add NOWAIT semantics for readdir disable fixed file for io_uring getdents for now fs/internal.h | 8 +++++ fs/readdir.c | 36 ++++++++++++++++----- fs/xfs/libxfs/xfs_da_btree.c | 16 ++++++++++ fs/xfs/libxfs/xfs_da_btree.h | 1 + fs/xfs/libxfs/xfs_dir2_block.c | 7 ++-- fs/xfs/libxfs/xfs_dir2_priv.h | 2 +- fs/xfs/scrub/dir.c | 2 +- fs/xfs/scrub/readdir.c | 2 +- fs/xfs/xfs_dir2_readdir.c | 58 +++++++++++++++++++++++++++------- fs/xfs/xfs_inode.c | 17 ++++++++++ fs/xfs/xfs_inode.h | 15 +++++---- include/linux/fs.h | 8 +++++ include/uapi/linux/io_uring.h | 7 ++++ io_uring/fs.c | 57 +++++++++++++++++++++++++++++++++ io_uring/fs.h | 3 ++ io_uring/opdef.c | 8 +++++ 16 files changed, 215 insertions(+), 32 deletions(-) -- 2.25.1
