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| author | Nick Piggin <npiggin@suse.de> | 2007-10-16 01:24:56 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:42:54 -0700 |
| commit | 5fe172370687e03cc6ba8dca990b75db18ff9bb3 (patch) | |
| tree | 8ce000fee15fa9ccd4313018f7f9ab1ffbc8cdaa /mm/filemap.c | |
| parent | ae37461c70bc8c8416cad1bab13a9898ed030aa1 (diff) | |
| download | lwn-5fe172370687e03cc6ba8dca990b75db18ff9bb3.tar.gz lwn-5fe172370687e03cc6ba8dca990b75db18ff9bb3.zip | |
mm: debug write deadlocks
Allow CONFIG_DEBUG_VM to switch off the prefaulting logic, to simulate the
Makes the race much easier to hit.
This is useful for demonstration and testing purposes, but is removed in a
subsequent patch.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index f74d05201862..0c54fc9b8e3d 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1878,6 +1878,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, if (maxlen > bytes) maxlen = bytes; +#ifndef CONFIG_DEBUG_VM /* * Bring in the user page that we will copy from _first_. * Otherwise there's a nasty deadlock on copying from the @@ -1885,6 +1886,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, * up-to-date. */ fault_in_pages_readable(buf, maxlen); +#endif page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec); if (!page) { |