From mboxrd@z Thu Jan  1 00:00:00 1970
From: Helge Deller <deller@gmx.de>
Subject: Re: [PATCH] parisc: Re: [PATCH] parisc: adjust L1_CACHE_BYTES to 128
 bytes on PA8800 and PA8900 CPUs
Date: Mon, 28 Sep 2015 17:57:32 +0200
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Cc: James Bottomley <James.Bottomley@HansenPartnership.com>,
	linux-parisc@vger.kernel.org
To: John David Anglin <dave.anglin@bell.net>
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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

Helge