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| author | Nick Piggin <npiggin@suse.de> | 2007-10-16 01:24:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:42:53 -0700 |
| commit | 001281881067a5998384c6669bc8dbbbab8456c4 (patch) | |
| tree | 6229d16c737782a36795354b218c74d4d2749752 | |
| parent | 557ed1fa2620dc119adb86b34c614e152a629a80 (diff) | |
| download | op-kernel-dev-001281881067a5998384c6669bc8dbbbab8456c4.zip op-kernel-dev-001281881067a5998384c6669bc8dbbbab8456c4.tar.gz | |
mm: use lockless radix-tree probe
Probing pages and radix_tree_tagged are lockless operations with the lockless
radix-tree. Convert these users to RCU locking rather than using tree_lock.
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>
| -rw-r--r-- | mm/page-writeback.c | 8 | ||||
| -rw-r--r-- | mm/readahead.c | 6 |
2 files changed, 5 insertions, 9 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 4472036..2adb899 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1022,17 +1022,15 @@ int test_set_page_writeback(struct page *page) EXPORT_SYMBOL(test_set_page_writeback); /* - * Return true if any of the pages in the mapping are marged with the + * Return true if any of the pages in the mapping are marked with the * passed tag. */ int mapping_tagged(struct address_space *mapping, int tag) { - unsigned long flags; int ret; - - read_lock_irqsave(&mapping->tree_lock, flags); + rcu_read_lock(); ret = radix_tree_tagged(&mapping->page_tree, tag); - read_unlock_irqrestore(&mapping->tree_lock, flags); + rcu_read_unlock(); return ret; } EXPORT_SYMBOL(mapping_tagged); diff --git a/mm/readahead.c b/mm/readahead.c index fc52f9f..c5c8981 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -149,20 +149,19 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp, /* * Preallocate as many pages as we will need. */ - read_lock_irq(&mapping->tree_lock); for (page_idx = 0; page_idx < nr_to_read; page_idx++) { pgoff_t page_offset = offset + page_idx; if (page_offset > end_index) break; + rcu_read_lock(); page = radix_tree_lookup(&mapping->page_tree, page_offset); + rcu_read_unlock(); if (page) continue; - read_unlock_irq(&mapping->tree_lock); page = page_cache_alloc_cold(mapping); - read_lock_irq(&mapping->tree_lock); if (!page) break; page->index = page_offset; @@ -171,7 +170,6 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp, SetPageReadahead(page); ret++; } - read_unlock_irq(&mapping->tree_lock); /* * Now start the IO. We ignore I/O errors - if the page is not |
