Messages in this thread | | | Date | Mon, 22 Aug 2011 22:09:36 +0300 | From | Dan Carpenter <> | Subject | Re: [PATCH] staging: zcache: fix possible sleep under lock |
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On Mon, Aug 22, 2011 at 01:47:49PM -0500, Seth Jennings wrote: > zcache_new_pool() calls kmalloc() with GFP_KERNEL which has > __GFP_WAIT set. However, zcache_new_pool() gets called on > a stack that holds the swap_lock spinlock, leading to a > possible sleep-with-lock situation. The lock is obtained > in enable_swap_info(). > > The patch replaces GFP_KERNEL with GFP_IOFS, which is > GFP_KERNEL & ~__GFP_WAIT. >
You should use GFP_ATOMIC. We don't want to do IO with the locks held. The only reason GFP_IOFS exists is so that we can turn off io during suspend and resume.
regards, dan carpenter
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