http://bugzilla.suse.com/show_bug.cgi?id=1168089 Bug ID: 1168089 Summary: reaim-io-disk-ext4 regression in 5.4 vs 5.5 Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: Other OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Kernel Assignee: kernel-maintainers@forge.provo.novell.com Reporter: jack@suse.com QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- Marvin has identified a regression in reaim-io-disk workload on ext4 filesystem between 5.4 and 5.5 kernels. It has bisected it down to: ast good/First bad commit ========================== Last good commit: 09edf4d381957b144440bac18a4769c53063b943 First bad commit: b1b4705d54abedfd69dcdf42779c521aa1e0fbd3
From b1b4705d54abedfd69dcdf42779c521aa1e0fbd3 Mon Sep 17 00:00:00 2001 From: Matthew Bobrowski <mbobrowski@mbobrowski.org> Date: Tue, 5 Nov 2019 23:01:37 +1100 Subject: [PATCH] ext4: introduce direct I/O read using iomap infrastructure
This patch introduces a new direct I/O read path which makes use of the iomap infrastructure. The new function ext4_do_read_iter() is responsible for calling into the iomap infrastructure via iomap_dio_rw(). If the read operation performed on the inode is not supported, which is checked via ext4_dio_supported(), then we simply fallback and complete the I/O using buffered I/O. Existing direct I/O read code path has been removed, as it is now redundant. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/f98a6f73fadddbfbad0fc5ed04f712ca0b799f37.157294932... it.mbobrowski@mbobrowski.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> fs/ext4/file.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- fs/ext4/inode.c | 38 +------------------------------------- 2 files changed, 54 insertions(+), 39 deletions(-) Comparison ========== good bad Hmean disk-1 2081.89 ( 0.00%) 2042.21 ( -1.91%) Hmean disk-41 93821.51 ( 0.00%) 84536.08 * -9.90%* Hmean disk-81 157689.81 ( 0.00%) 149079.75 * -5.46%* Hmean disk-121 193187.87 ( 0.00%) 188473.52 * -2.44%* Hmean disk-161 216591.93 ( 0.00%) 214000.89 * -1.20%* Hmean disk-201 241489.79 ( 0.00%) 237963.69 ( -1.46%) Hmean disk-241 256201.28 ( 0.00%) 252004.18 * -1.64%* Hmean disk-281 281845.54 ( 0.00%) 276665.57 * -1.84%* Hmean disk-321 286181.28 ( 0.00%) 281991.22 ( -1.46%) -- You are receiving this mail because: You are on the CC list for the bug.