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Re: svn commit: r1078357 - in /subversion/trunk: ./ build.conf subversion/libsvn_fs_fs/caching.c subversion/libsvn_fs_fs/fs.h subversion/libsvn_fs_fs/fs_fs.c subversion/svnadmin/main.c

From: Hyrum K Wright <hyrum_at_hyrumwright.org>
Date: Mon, 7 Mar 2011 10:36:44 -0600

On Mon, Mar 7, 2011 at 6:11 AM, Philip Martin
<philip.martin_at_wandisco.com> wrote:
> stefan2_at_apache.org writes:
>
>> Author: stefan2
>> Date: Sat Mar  5 21:18:33 2011
>> New Revision: 1078357
>
>> Modified: subversion/trunk/subversion/svnadmin/main.c
>> URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/svnadmin/main.c?rev=1078357&r1=1078356&r2=1078357&view=diff
>> ==============================================================================
>> --- subversion/trunk/subversion/svnadmin/main.c (original)
>> +++ subversion/trunk/subversion/svnadmin/main.c Sat Mar  5 21:18:33 2011
>> @@ -290,6 +290,11 @@ static const apr_getopt_option_t options
>>       N_("use format compatible with Subversion versions\n"
>>          "                             earlier than 1.7")},
>>
>> +    {"memory-cache-size",     'M', 1,
>> +     N_("size of the extra in-memory cache in MB used to\n"
>> +        "                             minimize redundant operations. Default: 256.\n"
>> +        "                             [used for FSFS repositories only]")},
>> +
>>      {NULL}
>>    };
>
>
>>
>> @@ -1650,6 +1656,7 @@ main(int argc, const char *argv[])
>>    /* Initialize opt_state. */
>>    opt_state.start_revision.kind = svn_opt_revision_unspecified;
>>    opt_state.end_revision.kind = svn_opt_revision_unspecified;
>> +  opt_state.memory_cache_size = 0x10000000; /* 256 MB */
>
> 256MB is a magic number.  How was its value determined?
>
> It causes the regression tests to fail on machines with 2GB of memory
> when the tests are run in parallel, as they cannot allocate 10*256MB.
>
> There appears to be a significant overhead setting up the cache.
> Setting the magic number to 16MB makes the tests noticeably faster,
> setting it to 1MB makes the tests faster still.

FWIW, my test run times increased by ~25% over the weekend. On IRC,
Philip speculated that this is a potential cause.

-Hyrum
Received on 2011-03-07 17:37:18 CET

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