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author | Fan Du <fan.du@windriver.com> | 2013-05-01 02:27:27 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-01 04:04:03 +0400 |
commit | 74e3d1e17b2e11d175970b85acd44f5927000ba2 (patch) | |
tree | 1adaccdd30702c8c151dfb97b13aaf241e092849 /kernel/smp.c | |
parent | 3440a1ca99707f093e9568ba9762764d3162dd8f (diff) | |
download | linux-74e3d1e17b2e11d175970b85acd44f5927000ba2.tar.xz |
include/linux/fs.h: disable preempt when acquire i_size_seqcount write lock
Two rt tasks bind to one CPU core.
The higher priority rt task A preempts a lower priority rt task B which
has already taken the write seq lock, and then the higher priority rt
task A try to acquire read seq lock, it's doomed to lockup.
rt task A with lower priority: call write
i_size_write rt task B with higher priority: call sync, and preempt task A
write_seqcount_begin(&inode->i_size_seqcount); i_size_read
inode->i_size = i_size; read_seqcount_begin <-- lockup here...
So disable preempt when acquiring every i_size_seqcount *write* lock will
cure the problem.
Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/smp.c')
0 files changed, 0 insertions, 0 deletions