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From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: "René Scharfe" <l.s.r@web•de>,
	"Michael Giuffrida" <michaelpg@chromium•org>,
	git@vger•kernel.org, "SZEDER Gábor" <szeder.dev@gmail•com>
Subject: Re: [BUG] add_again() off-by-one error in custom format
Date: Sun, 18 Jun 2017 21:46:34 -0700	[thread overview]
Message-ID: <xmqqd1a0vb2t.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20170618115017.wyroncb3jka6lrdt@sigill.intra.peff.net> (Jeff King's message of "Sun, 18 Jun 2017 07:50:17 -0400")

Jeff King <peff@peff•net> writes:

> On Sun, Jun 18, 2017 at 12:58:49PM +0200, René Scharfe wrote:
>
>> Anyway, here's a patch for stat-based invalidation, on top of the other
>> one.  Array removal is really slow (hope I didn't sneak a bug in there,
>> but my confidence in this code isn't very high).  No locking is done;
>> parallel threads removing and adding entries could make a mess, but
>> that's not an issue for log.
>> 
>> Timings for "time git log --pretty=%h >/dev/null" in my git repository
>> with 5094 loose objects on Debian:
>> 
>>         master       first patch  this patch
>> real    0m1.065s     0m0.581s     0m0.633s
>> user    0m0.648s     0m0.564s     0m0.580s
>> sys     0m0.412s     0m0.016s     0m0.052s
>> 
>> 
>> And on mingw with 227 loose objects:
>> 
>>         master       first patch  this patch
>> real    0m1.756s     0m0.546s     0m1.659s
>> user    0m0.000s     0m0.000s     0m0.000s
>> sys     0m0.000s     0m0.000s     0m0.000s
>> 
>> So at least for Windows it would be really nice if we could avoid
>> calling stat..
>
> Thanks for doing the timings. Given those numbers and the earlier
> discussion, I'd be inclined to skip the mtime check.

Yeah, thanks for these experiments.  With or without invalidation,
we already accept that racing with other processes will make the
result inaccurate, so I am also inclined to say that it would be
best to take the first one alone.


  reply	other threads:[~2017-06-19  4:46 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-12  3:13 [BUG] add_again() off-by-one error in custom format Michael Giuffrida
2017-06-12 22:49 ` Junio C Hamano
2017-06-13 18:09   ` René Scharfe
2017-06-13 18:29     ` Junio C Hamano
2017-06-13 20:29       ` René Scharfe
2017-06-13 21:20         ` Junio C Hamano
2017-06-14 18:24           ` René Scharfe
2017-06-15  5:56             ` Jeff King
2017-06-15 11:33               ` René Scharfe
2017-06-15 13:25                 ` Jeff King
2017-06-18 10:58                   ` René Scharfe
2017-06-18 11:49                     ` Jeff King
2017-06-18 12:59                       ` René Scharfe
2017-06-18 13:56                         ` Jeff King
2017-06-22 18:19                           ` René Scharfe
2017-06-22 23:15                             ` Jeff King
2017-06-18 10:58                   ` René Scharfe
2017-06-18 11:50                     ` Jeff King
2017-06-19  4:46                       ` Junio C Hamano [this message]
2017-06-22 18:19                         ` [PATCH] sha1_name: cache readdir(3) results in find_short_object_filename() René Scharfe
2017-06-22 23:10                           ` Jeff King
2017-06-24 12:12                             ` René Scharfe
2017-06-24 12:14                               ` Jeff King
2017-06-24 12:12                             ` René Scharfe
2017-06-24 12:20                               ` Jeff King
2017-06-24 14:09                                 ` René Scharfe
2017-06-24 14:12                                   ` Jeff King
2017-06-15 18:37             ` [BUG] add_again() off-by-one error in custom format Junio C Hamano
2017-06-13 22:24         ` SZEDER Gábor
2017-06-14 17:34           ` René Scharfe

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