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author | Mel Gorman <mgorman@suse.de> | 2012-07-31 16:44:19 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-31 18:42:46 -0700 |
commit | c93bdd0e03e848555d144eb44a1f275b871a8dd5 (patch) | |
tree | 8aff3bc2b9ff9f32e51040a7652bfb31257db626 /net/core/filter.c | |
parent | 7cb0240492caea2f6467f827313478f41877e6ef (diff) | |
download | op-kernel-dev-c93bdd0e03e848555d144eb44a1f275b871a8dd5.zip op-kernel-dev-c93bdd0e03e848555d144eb44a1f275b871a8dd5.tar.gz |
netvm: allow skb allocation to use PFMEMALLOC reserves
Change the skb allocation API to indicate RX usage and use this to fall
back to the PFMEMALLOC reserve when needed. SKBs allocated from the
reserve are tagged in skb->pfmemalloc. If an SKB is allocated from the
reserve and the socket is later found to be unrelated to page reclaim, the
packet is dropped so that the memory remains available for page reclaim.
Network protocols are expected to recover from this packet loss.
[a.p.zijlstra@chello.nl: Ideas taken from various patches]
[davem@davemloft.net: Use static branches, coding style corrections]
[sebastian@breakpoint.cc: Avoid unnecessary cast, fix !CONFIG_NET build]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/core/filter.c')
-rw-r--r-- | net/core/filter.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index d4ce2dc..907efd2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -83,6 +83,14 @@ int sk_filter(struct sock *sk, struct sk_buff *skb) int err; struct sk_filter *filter; + /* + * If the skb was allocated from pfmemalloc reserves, only + * allow SOCK_MEMALLOC sockets to use it as this socket is + * helping free memory + */ + if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) + return -ENOMEM; + err = security_sock_rcv_skb(sk, skb); if (err) return err; |