From: Michael Ellerman <mpe@ellerman.id.au>
To: Michael Neuling <mikey@neuling.org>, benh@kernel.crashing.org
Cc: linuxppc-dev@ozlabs.org, anton@samba.org, Cyril Bur <cyrilbur@gmail.com>
Subject: Re: [v3, 2/2] powerpc: Copy only required pieces of the mm_context_t to the paca
Date: Mon, 11 Jan 2016 20:14:01 +1100 (AEDT) [thread overview]
Message-ID: <20160111091402.01723140320@ozlabs.org> (raw)
In-Reply-To: <1449786882.29188.32.camel@neuling.org>
On Thu, 2015-10-12 at 22:34:42 UTC, Michael Neuling wrote:
> Currently we copy the whole mm_context_t to the paca but only access a
> few bits of it. This is wasteful of space paca and also takes quite
> some time in the hot path of context switching.
>
> This patch pulls in only the required bits from the mm_context_t to
> the paca and on context switch, copies only those.
>
> Benchmarking this (On top of Anton's recent MSR context switching
> changes [1]) using processes and yield shows an improvement of almost
> 3% on POWER8:
>
> http://ozlabs.org/~anton/junkcode/context_switch2.c
> ./context_switch2 --test=yield --process 0 0
>
> 1. https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-October/135700.html
>
> Signed-off-by: Michael Neuling <mikey@neuling.org>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/2fc251a8dda56b71ec491bee4c
cheers
next prev parent reply other threads:[~2016-01-11 9:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-28 4:54 [PATCH 1/2] powerpc: Add function to copy mm_context_t to the paca Michael Neuling
2015-10-28 4:54 ` [PATCH 2/2] powerpc: Copy only required pieces of the " Michael Neuling
2015-12-09 12:17 ` Anton Blanchard
2015-12-10 3:46 ` [PATCH v2 " Michael Neuling
2015-12-10 10:00 ` Michael Ellerman
2015-12-10 22:34 ` [PATCH v3 " Michael Neuling
2016-01-11 9:14 ` Michael Ellerman [this message]
2016-01-11 9:14 ` [1/2] powerpc: Add function to copy " Michael Ellerman
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