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Date: Fri, 19 Aug 2016 11:00:17 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>,
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        Tejun Heo <tj@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [LKP] [lkp] [xfs] 68a9f5e700: aim7.jobs-per-min -13.6% regression
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On Thu 18-08-16 15:25:40, Linus Torvalds wrote:
[...]
> So just for testing purposes, you could try changing that
> 
>         return alloc_pages(gfp, 0);
> 
> in __page_cache_alloc() into something like
> 
>         return alloc_pages_node(cpu_to_node(raw_smp_processor_id())), gfp, 0);

That would break mempolicies AFAICS. Anyway, I might be missing
something (the mempolicy kod has a strange sense for aesthetic) but the
normal case without any explicit mempolicy should use default_policy
which is MPOL_PREFERRED and MPOL_F_LOCAL which means numa_node_id() so
the local node. So the above two should do the same thing unless I have
missing something.
-- 
Michal Hocko
SUSE Labs

From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Michal Hocko <mhocko@kernel.org>
To: lkp@lists.01.org
Subject: Re: [xfs] 68a9f5e700: aim7.jobs-per-min -13.6% regression
Date: Fri, 19 Aug 2016 11:00:17 +0200
Message-ID: <20160819090017.GF32619@dhcp22.suse.cz>
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On Thu 18-08-16 15:25:40, Linus Torvalds wrote:
[...]
> So just for testing purposes, you could try changing that
> =

>         return alloc_pages(gfp, 0);
> =

> in __page_cache_alloc() into something like
> =

>         return alloc_pages_node(cpu_to_node(raw_smp_processor_id())), gfp=
, 0);

That would break mempolicies AFAICS. Anyway, I might be missing
something (the mempolicy kod has a strange sense for aesthetic) but the
normal case without any explicit mempolicy should use default_policy
which is MPOL_PREFERRED and MPOL_F_LOCAL which means numa_node_id() so
the local node. So the above two should do the same thing unless I have
missing something.
-- =

Michal Hocko
SUSE Labs

--===============3342054054972907480==--