From: Jonathan Toppins <jtoppins@cumulusnetworks•com>
To: Crestez Dan Leonard <cdleonard@gmail•com>, netdev@vger•kernel.org
Subject: Re: [RFC] tcp md5 use of alloc_percpu
Date: Wed, 22 Oct 2014 19:38:31 -0400 [thread overview]
Message-ID: <54483FF7.4090208@cumulusnetworks.com> (raw)
In-Reply-To: <5447FDB2.2010906@gmail.com>
On 10/22/14, 2:55 PM, Crestez Dan Leonard wrote:
> sg_init_one does virt_addr on the pointer which assumes it is directly accessible. But the tcp_md5sig_pool pointer comes from alloc_percpu which can return memory from the vmalloc area after the pcpu_first_chunk is exhausted. This looks wrong to me. I'm am getting crashes on mips and I believe this to be the cause.
Thinking about this more if the issue really is sg_init_one assumes a
directly accessible memory region, can we just modify the zone
allocation to GFP_DMA using alloc_percpu_gfp()? Does this satisfy the
assumptions made by sg_init_one?
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1bec4e7..6924320 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2889,7 +2889,7 @@ static void __tcp_alloc_md5sig_pool(void)
int cpu;
struct tcp_md5sig_pool __percpu *pool;
- pool = alloc_percpu(struct tcp_md5sig_pool);
+ pool = alloc_percpu_gfp(struct tcp_md5sig_pool, GFP_DMA);
if (!pool)
return;
next prev parent reply other threads:[~2014-10-22 23:38 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-22 18:55 [RFC] tcp md5 use of alloc_percpu Crestez Dan Leonard
2014-10-22 19:12 ` Eric Dumazet
2014-10-22 21:35 ` Jonathan Toppins
2014-10-22 23:05 ` Crestez Dan Leonard
2014-10-24 9:33 ` Herbert Xu
2014-10-22 21:53 ` David Miller
2014-10-22 23:38 ` Jonathan Toppins [this message]
2014-10-23 1:00 ` Crestez Dan Leonard
2014-10-23 1:47 ` Eric Dumazet
2014-10-23 4:40 ` David Ahern
2014-10-23 5:23 ` Eric Dumazet
2014-10-23 5:38 ` Eric Dumazet
2014-10-23 6:58 ` Jonathan Toppins
2014-10-23 13:21 ` Eric Dumazet
2014-10-23 14:43 ` Eric Dumazet
2014-10-23 16:17 ` Crestez Dan Leonard
2014-10-23 19:22 ` Eric Dumazet
2014-10-23 16:33 ` [PATCH net] tcp: md5: percpu tcp_md5sig_pool must not span pages Eric Dumazet
2014-10-23 19:34 ` Eric Dumazet
2014-10-23 19:58 ` [PATCH v2 net] tcp: md5: do not use alloc_percpu() Eric Dumazet
2014-10-23 20:44 ` David Ahern
2014-10-23 22:57 ` Eric Dumazet
2014-10-23 23:36 ` David Ahern
2014-10-24 3:45 ` David Ahern
2014-10-25 20:11 ` David Miller
2014-10-23 14:46 ` [RFC] tcp md5 use of alloc_percpu Crestez Dan Leonard
2014-10-23 13:03 ` Crestez Dan Leonard
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