Re: [PATCH 01/12] netvm: Prevent a stream-specific deadlock

On Wed, Jun 20, 2012 at 10:37:50AM +0100, Mel Gorman wrote:

It could happen that all !SOCK_MEMALLOC sockets have buffered so
much data that we're over the global rmem limit. This will prevent
SOCK_MEMALLOC buffers from receiving data, which will prevent userspace
from running, which is needed to reduce the buffered data.

Fix this by exempting the SOCK_MEMALLOC sockets from the rmem limit.
Once this change it applied, it is important that sockets that set
SOCK_MEMALLOC do not clear the flag until the socket is being torn down.
If this happens, a warning is generated and the tokens reclaimed to
avoid accounting errors until the bug is fixed.

[davem@davemloft.net: Warning about clearing SOCK_MEMALLOC]
Signed-off-by: Peter Zijlstra <redacted>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>

This patch introduced a new warning that I had previously missed. I'll
fix it up when rebasing this series on top of linux-next.

-- 
Mel Gorman
SUSE Labs

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