From: Ben Tebulin <tebulin@googlemail.com>
Date: Wed, 14 Aug 2013 09:29:22 GMT
Subject: Reproducible, corrupt packfile after fresh git-svn checkouts - IDENTIFIED
Message-ID: <520B4DF2.207@gmail.com>
In-Reply-To: <5204E67D.9090106@googlemail.com>

Hello everybody!

I'm the guy having the issue, that in a particular Git repository the
reads of an object fail the SHA1 reproducible on *two independent
machines* .

The issue occurs on a very specific repository starting with Linux
Kernel 3.7.2. Unfortunately my E-Mail to the kernel list dit get no
response.

After a long session of rebooting and bisecting the Linux kernel
(fortunately I had a SSD and ccache!) I was able to pinpoint this to the
following patch related to _memory management_ causing my data
corruption with git:

*"mm: limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT"*
  787f7301074ccd07a3e82236ca41eefd245f4e07 linux stable [1]
  53a59fc67f97374758e63a9c785891ec62324c81 upstream commit [2]

The patch speaks about "batching [memory] pages to be freed" so I'm a
bit unsure: Is this a Git or a Linux kernel issue?


Thanks
- Ben


[1] https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=787f7301074ccd07a3e82236ca41eefd245f4e07
[2] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=53a59fc67f97374758e63a9c785891ec62324c81