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From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Nikolay Borisov <n.borisov@siteground.com>,
	Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
	Nikolay Borisov <kernel@kyup.com>,
	David Miller <davem@davemloft.net>,
	netfilter-devel@vger.kernel.org, netdev@vger.kernel.org,
	SiteGround Operations <operations@siteground.com>
Subject: Re: [PATCH v2] netfilter: ipset: Fix sleeping memory allocation in atomic context
Date: Fri, 16 Oct 2015 11:22:12 +0200	[thread overview]
Message-ID: <20151016092212.GA1092@salvia> (raw)
In-Reply-To: <1444942391.25595.11.camel@edumazet-glaptop2.roam.corp.google.com>

On Thu, Oct 15, 2015 at 01:53:11PM -0700, Eric Dumazet wrote:
> On Thu, 2015-10-15 at 23:20 +0300, Nikolay Borisov wrote:
> 
> > While GFP_ATOMIC does indeed look the correct solution for this particular
> > case I was wondering whether something like (GFP_KERNEL & ~__GFP_WAIT)
> > wouldn't also make the cut without causing sleeping? I guess this is exactly
> > the sort of situation that Mel Gorman's patch can address
> > (marc.info/?l=linux-kernel&m=144283282101953) ?
> 
> This is not applicable here, because the caller would have to find a way
> to keep trying.
> 
> I believe one way to handle this problem (in a followup patch) would be
> to use a work queue for the gc, not a timer.
> 
> Using a timer for gc is almost always subject to big problems anyway.

Agreed, this is what we're doing in nft_hash. Thanks for feedback Eric!

  reply	other threads:[~2015-10-16  9:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-15 10:56 [PATCH v2] netfilter: ipset: Fix sleeping memory allocation in atomic context Nikolay Borisov
2015-10-15 13:32 ` Eric Dumazet
2015-10-15 13:41   ` Nikolay Borisov
2015-10-15 14:32     ` Eric Dumazet
2015-10-15 14:49       ` Nikolay Borisov
2015-10-15 18:25       ` Jozsef Kadlecsik
2015-10-15 18:46         ` Eric Dumazet
2015-10-15 20:20           ` Nikolay Borisov
2015-10-15 20:53             ` Eric Dumazet
2015-10-16  9:22               ` Pablo Neira Ayuso [this message]
2015-10-16  9:27               ` Jozsef Kadlecsik

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