The patch titled
mm: readahead scan lockless
has been added to the -mm tree. Its filename is
mm-readahead-scan-lockless.patch
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------------------------------------------------------
Subject: mm: readahead scan lockless
From: Nick Piggin <npiggin@xxxxxxx>
radix_tree_next_hole() is implemented as a series of radix_tree_lookup()s.
So it can be called locklessly, under rcu_read_lock().
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/readahead.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff -puN mm/readahead.c~mm-readahead-scan-lockless mm/readahead.c
--- a/mm/readahead.c~mm-readahead-scan-lockless
+++ a/mm/readahead.c
@@ -382,9 +382,9 @@ ondemand_readahead(struct address_space
if (hit_readahead_marker) {
pgoff_t start;
- read_lock_irq(&mapping->tree_lock);
- start = radix_tree_next_hole(&mapping->page_tree, offset, max+1);
- read_unlock_irq(&mapping->tree_lock);
+ rcu_read_lock();
+ start = radix_tree_next_hole(&mapping->page_tree, offset,max+1);
+ rcu_read_unlock();
if (!start || start - offset > max)
return 0;
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
hugetlb-fix-lockdep-error.patch
linux-next.patch
spufs-convert-nopfn-to-fault.patch
vt-fix-vc_resize-locking.patch
mspec-convert-nopfn-to-fault.patch
mspec-convert-nopfn-to-fault-fix.patch
mm-remove-nopfn.patch
mm-remove-double-indirection-on-tlb-parameter-to-free_pgd_range-co.patch
hugetlb-guarantee-that-cow-faults-for-a-process-that-called-mmapmap_private-on-hugetlbfs-will-succeed-build-fix.patch
x86-implement-pte_special.patch
mm-introduce-get_user_pages_fast.patch
mm-introduce-get_user_pages_fast-checkpatch-fixes.patch
x86-lockless-get_user_pages_fast.patch
x86-lockless-get_user_pages_fast-checkpatch-fixes.patch
x86-lockless-get_user_pages_fast-fix.patch
x86-lockless-get_user_pages_fast-fix-warning.patch
dio-use-get_user_pages_fast.patch
splice-use-get_user_pages_fast.patch
mm-readahead-scan-lockless.patch
radix-tree-add-gang_lookup_slot-gang_lookup_slot_tag.patch
mm-speculative-page-references.patch
mm-lockless-pagecache.patch
mm-spinlock-tree_lock.patch
powerpc-implement-pte_special.patch
powerpc-lockless-get_user_pages_fast.patch
reiser4.patch
likeliness-accounting-change-and-cleanup.patch
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