This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCHv3] powerpc: Replace lxvd2x/stxvd2x with lvx/stvx in P7's memcpy/memmove
- From: "Tulio Magno Quites Machado Filho" <tuliom at linux dot vnet dot ibm dot com>
- To: Florian Weimer <fweimer at redhat dot com>, Adhemerval Zanella <adhemerval dot zanella at linaro dot org>, "Carlos O'Donell" <carlos at redhat dot com>, libc-alpha at sourceware dot org
- Cc: raji at linux dot vnet dot ibm dot com
- Cc:
- Date: Tue, 21 Nov 2017 09:17:50 -0200
- Subject: Re: [PATCHv3] powerpc: Replace lxvd2x/stxvd2x with lvx/stvx in P7's memcpy/memmove
- Authentication-results: sourceware.org; auth=none
- References: <2f3d25f5-bbd6-b409-4658-50bc172c258b@linaro.org> <20171020192239.24706-1-tuliom@linux.vnet.ibm.com> <d3482b31-77af-33f0-f598-985bbbdc55f3@redhat.com>
Florian Weimer <fweimer@redhat.com> writes:
> On 10/20/2017 09:22 PM, Tulio Magno Quites Machado Filho wrote:
>> From: Rajalakshmi Srinivasaraghavan<raji@linux.vnet.ibm.com>
>>
>> POWER9 DD2.1 and earlier has an issue where some cache inhibited
>> vector load traps to the kernel, causing a performance degradation. To
>> handle this in memcpy and memmove, lvx/stvx is used for aligned
>> addresses instead of lxvd2x/stxvd2x.
>>
>> Reference:https://patchwork.ozlabs.org/patch/814059/
>>
>> 2017-10-20 Rajalakshmi Srinivasaraghavan<raji@linux.vnet.ibm.com>
>>
>> * sysdeps/powerpc/powerpc64/power7/memcpy.S: Replace
>> lxvd2x/stxvd2x with lvx/stvx.
>> * sysdeps/powerpc/powerpc64/power7/memmove.S: Likewise.
>>
>> Reviewed-by: Tulio Magno Quites Machado Filho<tuliom@linux.vnet.ibm.com>
>
> Should we backport this change, to 2.26 in particular?
Yes. That's a good idea.
--
Tulio Magno