From: Mel Gorman <mgorman@suse.de>
To: Micha? Miros?aw <mirqus@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
Linux-Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>, Neil Brown <neilb@suse.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 10/14] netvm: Set PF_MEMALLOC as appropriate during SKB processing
Date: Thu, 9 Jun 2011 13:56:42 +0100 [thread overview]
Message-ID: <20110609125642.GS5247@suse.de> (raw)
In-Reply-To: <BANLkTi=8jx8B8fR_+Z76UoTe_jhG9G-Tyw@mail.gmail.com>
On Thu, Jun 09, 2011 at 02:28:24PM +0200, Micha? Miros?aw wrote:
> 2011/6/9 Mel Gorman <mgorman@suse.de>:
> > On Thu, Jun 09, 2011 at 12:21:31PM +0200, Micha? Miros?aw wrote:
> >> 2011/6/9 Mel Gorman <mgorman@suse.de>:
> >> [...]
> >> > +/*
> >> > + * Limit which protocols can use the PFMEMALLOC reserves to those that are
> >> > + * expected to be used for communication with swap.
> >> > + */
> >> > +static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
> >> > +{
> >> > + switch (skb->protocol) {
> >> > + case __constant_htons(ETH_P_ARP):
> >> > + case __constant_htons(ETH_P_IP):
> >> > + case __constant_htons(ETH_P_IPV6):
> >> > + case __constant_htons(ETH_P_8021Q):
> >> > + return true;
> >> > + default:
> >> > + return false;
> >> > + }
> >> > +}
> >>
> >> This is not needed and wrong. Whatever list there will be, it's going
> >> to always miss some obscure setup (or not that obscure, like
> >> ATAoverEthernet).
> >>
> >
> > NBD is updated in the series to set the socket information
> > appropriately but the same cannot be said of AoE. The necessary
> > changes have been made IPv4 and IPv6 to handle pfmemalloc sockets
> > but the same cannot be necessarily said for the other protocols. Yes,
> > the check could be removed but leaving it there makes a clear statement
> > on what scenario can be reasonably expected to work.
>
> Ok. Then the comment before skb_pfmemalloc_protocol() is misleading.
> It should say that this is a list of protocols which implement the
> required special handling of PFMEMALLOC skbs.
>
That's a very reasonable suggestion. My thinking behind that comment
was a backwards because I only "expected" protocols that implemented
the special handling to be used for swap :/
Thanks.
--
Mel Gorman
SUSE Labs
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next prev parent reply other threads:[~2011-06-09 12:56 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-09 8:02 [PATCH 00/14] Swap-over-NBD without deadlocking v4r3 Mel Gorman
2011-06-09 8:02 ` [PATCH 01/14] mm: Serialize access to min_free_kbytes Mel Gorman
2011-06-09 8:02 ` [PATCH 02/14] mm: sl[au]b: Add knowledge of PFMEMALLOC reserve pages Mel Gorman
2011-06-09 8:02 ` [PATCH 03/14] mm: Introduce __GFP_MEMALLOC to allow access to emergency reserves Mel Gorman
2011-06-09 8:02 ` [PATCH 04/14] mm: allow PF_MEMALLOC from softirq context Mel Gorman
2011-06-09 8:02 ` [PATCH 05/14] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Mel Gorman
2011-06-09 8:02 ` [PATCH 06/14] net: Introduce sk_allocation() to allow addition of GFP flags depending on the individual socket Mel Gorman
2011-06-09 8:02 ` [PATCH 07/14] netvm: Allow the use of __GFP_MEMALLOC by specific sockets Mel Gorman
2011-06-09 8:02 ` [PATCH 08/14] netvm: Allow skb allocation to use PFMEMALLOC reserves Mel Gorman
2011-06-09 8:02 ` [PATCH 09/14] netvm: Propagate page->pfmemalloc to skb Mel Gorman
2011-06-09 8:02 ` [PATCH 10/14] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2011-06-09 10:21 ` Michał Mirosław
2011-06-09 11:35 ` Mel Gorman
2011-06-09 12:28 ` Michał Mirosław
2011-06-09 12:56 ` Mel Gorman [this message]
2011-06-09 8:02 ` [PATCH 11/14] mm: Micro-optimise slab to avoid a function call Mel Gorman
2011-06-09 8:02 ` [PATCH 12/14] nbd: Set SOCK_MEMALLOC for access to PFMEMALLOC reserves Mel Gorman
2011-06-09 8:02 ` [PATCH 13/14] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage Mel Gorman
2011-06-09 8:02 ` [PATCH 14/14] mm: Account for the number of times direct reclaimers get throttled Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2011-06-20 13:12 [PATCH 00/14] Swap-over-NBD without deadlocking v5 Mel Gorman
2011-06-20 13:12 ` [PATCH 10/14] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2011-09-09 10:57 [PATCH 00/14] Swap-over-NBD without deadlocking v6 Mel Gorman
2011-09-09 10:57 ` [PATCH 10/14] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2011-10-06 12:41 [PATCH 00/14] Swap-over-NBD without deadlocking V7 Mel Gorman
2011-10-06 12:41 ` [PATCH 10/14] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
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