From mboxrd@z Thu Jan 1 00:00:00 1970 From: John David Anglin Subject: Re: [PATCH] parisc: Re: [PATCH] parisc: adjust L1_CACHE_BYTES to 128 bytes on PA8800 and PA8900 CPUs Date: Mon, 28 Sep 2015 16:00:03 -0400 Message-ID: <56099C43.70705@bell.net> References: <20150902162000.GC2444@ls3530.box> <1441287043.2235.6.camel@HansenPartnership.com> <1441288665.2235.17.camel@HansenPartnership.com> <55EB5EFA.4040407@gmx.de> <56017FB3.5050709@gmx.de> <65929045-FF25-4BFB-BA89-F07A47328F1F@bell.net> <5609636C.7010604@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Cc: James Bottomley , linux-parisc@vger.kernel.org To: Helge Deller Return-path: In-Reply-To: <5609636C.7010604@gmx.de> List-ID: List-Id: linux-parisc.vger.kernel.org On 2015-09-28 11:57 AM, Helge Deller wrote: > Hi Dave, > > On 27.09.2015 18:27, John David Anglin wrote: >> On 2015-09-22, at 12:20 PM, Helge Deller wrote: >>> The baseline for all results is the timing with a vanilla kernel 4.2: >>> real 0m13.596s >>> user 0m18.152s >>> sys 0m35.752s >>> >>> >>> The next results are with the atomic_hash (a) patch applied: >>> For ATOMIC_HASH_SIZE = 4. >>> real 0m21.892s >>> user 0m27.492s >>> sys 0m59.704s >>> >>> For ATOMIC_HASH_SIZE = 64. >>> real 0m20.604s >>> user 0m24.832s >>> sys 0m56.552s >>> >> Attached is a revised patch "a" to try to improve performance of atomic_t variables. If you get a chance, could >> you see how it performs. > here are the numbers for your revised "a" patch (on top of vanilla kernel 4.2): > > real 0m20.040s > user 0m22.876s > sys 0m56.724s > (Variations can be around +- 0.5 seconds) > > If you want to test yourself: > The testcase executable is on sibaris: /home/var_lib_sbuild_build/libatomic/libatomic-ops-7.4.2/test_atomic It doesn't seem like the padding has much difference. I had hoped for better although the test probably doesn't test atomic_t variables. The regression from the the vanilla kernel is a problem. Dave -- John David Anglin dave.anglin@bell.net