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percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages

commit 320661b08d upstream.

Update to pcpu_nr_empty_pop_pages in pcpu_alloc() is currently done
without holding pcpu_lock. This can lead to bad updates to the variable.
Add missing lock calls.

Fixes: b539b87fed ("percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
steinar/wifi_calib_4_9_kernel
Tahsin Erdogan 2017-02-25 13:00:19 -08:00 committed by Greg Kroah-Hartman
parent a33e71c5f0
commit 3f406ecddf
1 changed files with 4 additions and 1 deletions

View File

@ -1010,8 +1010,11 @@ area_found:
mutex_unlock(&pcpu_alloc_mutex);
}
if (chunk != pcpu_reserved_chunk)
if (chunk != pcpu_reserved_chunk) {
spin_lock_irqsave(&pcpu_lock, flags);
pcpu_nr_empty_pop_pages -= occ_pages;
spin_unlock_irqrestore(&pcpu_lock, flags);
}
if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW)
pcpu_schedule_balance_work();