Messages in this thread | | | Date | Tue, 27 Oct 2015 12:16:52 -0600 | From | Jason Gunthorpe <> | Subject | Re: [PATCH] IB/sa: replace GFP_KERNEL with GFP_ATOMIC |
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On Tue, Oct 27, 2015 at 02:12:36PM -0400, ira.weiny wrote: > On Tue, Oct 27, 2015 at 09:17:40PM +0530, Saurabh Sengar wrote: > > replace GFP_KERNEL with GFP_ATOMIC, as code while holding a spinlock > > should be atomic > > GFP_KERNEL may sleep and can cause deadlock, where as GFP_ATOMIC may > > fail but certainly avoids deadlock > > Great catch. Thanks! > > However, gfp_t is passed to send_mad and we should pass that down and use it.
> spin_lock_irqsave(&ib_nl_request_lock, flags); > - ret = ib_nl_send_msg(query); > + ret = ib_nl_send_msg(query, gfp_mask);
A spin lock is guarenteed held around ib_nl_send_msg, so it's allocations have to be atomic, can't use gfp_mask here..
I do wonder if it is a good idea to call ib_nl_send_msg with a spinlock held though.. Would be nice to see that go away.
Jason
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