From: "Timo Teräs" <timo.teras@iki.fi>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Herbert Xu <herbert@gondor.apana.org.au>, netdev@vger.kernel.org
Subject: Re: [PATCH 3/7] flow: allocate hash table for online cpus only
Date: Wed, 31 Mar 2010 16:27:36 +0300 [thread overview]
Message-ID: <4BB34DC8.7080903@iki.fi> (raw)
In-Reply-To: <201003312302.51683.rusty@rustcorp.com.au>
Rusty Russell wrote:
> On Tue, 30 Mar 2010 10:42:55 pm Herbert Xu wrote:
>> On Mon, Mar 29, 2010 at 05:12:40PM +0300, Timo Teras wrote:
>>> Instead of unconditionally allocating hash table for all possible
>>> cpu's, allocate it only for online cpu's and release related
>>> memory if cpu goes down.
>>>
>>> Signed-off-by: Timo Teras <timo.teras@iki.fi>
>> Hmm that's where we started but then Rusty changed it back in 2004:
>>
>> So I'd like to hear his opinion on changing it back again.
>
> It was pretty unique at the time, it no longer is, so the arguments are less
> compelling IMHO.
>
> However, we can now use a dynamic percpu variable and get it as a real
> per-cpu thing (which currently means it *will* be for every available cpu,
> not just online ones). Haven't thought about it, but that change might be
> worth considering instead?
I did convert most of the static percpu variables to a struct which
is allocated dynamically using alloc_percpu. See:
http://marc.info/?l=linux-netdev&m=127003066905912&w=2
This patch is on top of that, to avoid allocating the larger hash
table unconditionally as amount of possible cpu's can be large.
If you take a look at the actual patch to add back the hash allocation
for only 'online' cpu's, it's not that complicated IMHO:
http://marc.info/?l=linux-netdev&m=126987200927472&w=2
next prev parent reply other threads:[~2010-03-31 13:27 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-29 14:12 [PATCH 0/7] caching bundles, iteration 2 Timo Teras
2010-03-29 14:12 ` [PATCH 1/7] xfrm: remove policy lock when accessing policy->walk.dead Timo Teras
2010-03-29 14:43 ` Herbert Xu
2010-03-30 4:55 ` Timo Teräs
2010-03-30 11:53 ` Herbert Xu
2010-03-30 12:04 ` Timo Teräs
2010-03-30 12:14 ` Herbert Xu
2010-03-30 12:21 ` Timo Teräs
2010-03-30 12:23 ` Herbert Xu
2010-03-30 12:41 ` Timo Teräs
2010-03-30 12:48 ` Herbert Xu
2010-03-30 13:33 ` Timo Teräs
2010-03-30 14:30 ` Herbert Xu
2010-03-30 14:34 ` Herbert Xu
2010-03-30 14:37 ` Herbert Xu
2010-03-30 14:01 ` Timo Teräs
2010-03-30 14:29 ` Herbert Xu
2010-03-30 15:36 ` Timo Teräs
2010-03-31 0:43 ` Herbert Xu
2010-03-29 14:12 ` [PATCH 2/7] flow: structurize flow cache Timo Teras
2010-03-30 12:01 ` Herbert Xu
2010-03-30 12:02 ` Timo Teräs
2010-03-30 12:15 ` Herbert Xu
2010-03-29 14:12 ` [PATCH 3/7] flow: allocate hash table for online cpus only Timo Teras
2010-03-30 12:12 ` Herbert Xu
2010-03-31 12:32 ` Rusty Russell
2010-03-31 13:27 ` Timo Teräs [this message]
2010-03-29 14:12 ` [PATCH 4/7] flow: delayed deletion of flow cache entries Timo Teras
2010-03-30 12:22 ` Herbert Xu
2010-03-30 12:32 ` Timo Teräs
2010-03-30 12:36 ` Herbert Xu
2010-03-30 12:43 ` Timo Teräs
2010-03-29 14:12 ` [PATCH 5/7] flow: virtualize get and entry deletion methods Timo Teras
2010-03-29 14:12 ` [PATCH 6/7] xfrm: cache bundles instead of policies for outgoing flows Timo Teras
2010-03-29 14:12 ` [PATCH 7/7] xfrm: remove policy garbage collection Timo Teras
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