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From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>,
	git@vger.kernel.org, Ben Peart <benpeart@microsoft.com>,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 0/2] Fix fsmonitor after discard_index()
Date: Thu, 23 May 2019 22:49:19 +0200 (CEST)	[thread overview]
Message-ID: <nycvar.QRO.7.76.6.1905232245390.46@tvgsbejvaqbjf.bet> (raw)
In-Reply-To: <87ef74a1dv.fsf@evledraar.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1693 bytes --]

Hi Ævar,

On Mon, 18 Mar 2019, Ævar Arnfjörð Bjarmason wrote:

>
> On Sat, Mar 16 2019, Johannes Schindelin via GitGitGadget wrote:
>
> > It was reported by Ævar Arnfjörð Bjarmason
> > [https://public-inbox.org/git/nycvar.QRO.7.76.6.1903142058130.41@tvgsbejvaqbjf.bet/T/#mb8718fe52e4721dacd3b143a09187ff9090ef4e3]
> > that there were problems with the fsmonitor feature in conjunction
> > with the newly built-in git stash/git rebase.
> >
> > The culprit really is that the fsmonitor flag that says whether it was
> > queried already was not re-set after discard_index() was called by
> > mistake.
> >
> > This fixes that, and apparently also other long-standing fsmonitor
> > issues.
>
> I've added this to my internal build & now the test suite passes in the
> fsmonitor mode without any test skipping.
>
> > (Note that there is still a flakiness around t7519
> > [https://github.com/git-for-windows/git/pull/2127#pullrequestreview-215010574]
> > where it tries to make sure that the fsmonitor hook can prevent unnecessary
> > lstat() calls, but that seems to be unrelated to this here bug.)
>
> FWIW Since February 1st, 2018 I've run my builds on CentOS [67] through
> an GIT_FSMONITOR_TEST=$PWD/t7519/fsmonitor-all test and have never
> encountered this flakyness, and I built pretty much on every "next"
> push-out.
>
> The fix sounds good, just one data point on the rarity of the race in
> practice. I hadn't noticed this being flaky.

I finally found some time to track this down (it only took me two
days...): it is a racy condition that *hides* the bug.

Details and a fix in https://github.com/gitgitgadget/git/pull/223

Ciao,
Dscho

  parent reply	other threads:[~2019-05-23 20:49 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-16  9:49 [PATCH 0/2] Fix fsmonitor after discard_index() Johannes Schindelin via GitGitGadget
2019-03-16  9:49 ` [PATCH 1/2] fsmonitor: demonstrate that it is not refreshed " Johannes Schindelin via GitGitGadget
2019-03-16 10:26   ` Johannes Sixt
2019-03-21 12:32     ` Johannes Schindelin
2019-03-16  9:49 ` [PATCH 2/2] fsmonitor: force a refresh after the index was discarded Johannes Schindelin via GitGitGadget
2019-03-18 11:05 ` [PATCH 0/2] Fix fsmonitor after discard_index() Ævar Arnfjörð Bjarmason
2019-03-21 14:36   ` Johannes Schindelin
2019-05-23 20:49   ` Johannes Schindelin [this message]
2019-03-21 13:57 ` [PATCH v2 " Johannes Schindelin via GitGitGadget
2019-03-21 13:57   ` [PATCH v2 1/2] fsmonitor: demonstrate that it is not refreshed " Johannes Schindelin via GitGitGadget
2019-03-21 13:57   ` [PATCH v2 2/2] fsmonitor: force a refresh after the index was discarded Johannes Schindelin via GitGitGadget
2019-03-22 11:04     ` SZEDER Gábor
2019-05-07 11:10   ` [PATCH v3 0/2] Fix fsmonitor after discard_index() Ævar Arnfjörð Bjarmason
2019-05-07 14:00     ` Junio C Hamano
2019-05-08  3:12       ` Junio C Hamano
2019-05-07 11:10   ` [PATCH v3 1/2] fsmonitor: demonstrate that it is not refreshed " Ævar Arnfjörð Bjarmason
2019-05-07 11:10   ` [PATCH v3 2/2] fsmonitor: force a refresh after the index was discarded Ævar Arnfjörð Bjarmason

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