From: Anton Blanchard <anton@samba.org>
To: Michael Neuling <mikey@neuling.org>
Cc: Anton Blanchard <anton@ozlabs.org>,
mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org,
aneesh.kumar@linux.vnet.ibm.com, acsawdey@linux.vnet.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 2/3] powerpc: Avoid load hit store in setup_sigcontext()
Date: Mon, 30 May 2016 09:23:40 +1000 [thread overview]
Message-ID: <20160530092340.4244948c@kryten> (raw)
In-Reply-To: <1464563663.27056.74.camel@neuling.org>
Hi,
> On Sun, 2016-05-29 at 22:03 +1000, Anton Blanchard wrote:
> > From: Anton Blanchard <anton@samba.org>
> >
> > In setup_sigcontext(), we set current->thread.vrsave then use it
> > straight after. Since current is hidden from the compiler via inline
> > assembly, it cannot optimise this and we end up with a load hit
> > store.
>
> Is setup_sigcontext() really a fast path we need to optimise?
setup_sigcontext() is called for every signal we deliver. I'd like
userspace to use less signals, but we still stumble across workloads
with quite heavy use of them.
Anton
next prev parent reply other threads:[~2016-05-29 23:24 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-29 12:03 [PATCH 1/3] powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() Anton Blanchard
2016-05-29 12:03 ` [PATCH 2/3] powerpc: Avoid load hit store in setup_sigcontext() Anton Blanchard
2016-05-29 23:14 ` Michael Neuling
2016-05-29 23:23 ` Anton Blanchard [this message]
2016-06-15 12:39 ` [2/3] " Michael Ellerman
2016-05-29 12:03 ` [PATCH 3/3] powerpc: Avoid load hit store when using find_linux_pte_or_hugepte() Anton Blanchard
2016-05-30 5:17 ` Aneesh Kumar K.V
2016-05-30 23:29 ` Michael Ellerman
2016-05-31 3:29 ` Aneesh Kumar K.V
2016-05-31 4:18 ` Michael Ellerman
2016-05-31 6:52 ` Aneesh Kumar K.V
2016-06-01 3:43 ` [3/3] " Michael Ellerman
2016-06-01 5:35 ` Anton Blanchard
2016-05-30 8:15 ` [PATCH 1/3] powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() Gabriel Paubert
2016-05-31 10:09 ` Anton Blanchard
2016-06-01 3:06 ` Michael Ellerman
2016-06-15 12:39 ` [1/3] " Michael Ellerman
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