Please see the following Chromium bug, comment #70 for background: https://code.google.com/p/chromium/issues/detail?id=415681 Chromium's GPU process sandbox limits filesystem access to a predetermined whitelist. libxshmfence needs to create temporary shared memory files and the location for these files is decided at build time as a config param. This should be /dev/shm and this is the path Chromium whitelists. On Fedora builds the shared memory files are being placed in /var/tmp. Putting shared memory files in /var/tmp or /tmp isn't the right place for them. It doesn't seem right to whitelist these extra paths in Chromium when they should be in /dev/shm. Would it possible to change the Fedora build config so these files are placed more appropriately (in /dev/shm), thus being inline with other distros and compatible with Chromium. Many thanks
I think I found another issue with shmfd files placed in /var/tmp: the Xorg process blocks on disk sometimes. Probably this is root cause of UI hiccups experienced in every 2-3 minutes on my desktop from Fedora 21. The following stack trace observer in /proc/16539/stack for about 500ms while the Xorg process was in state D: [<ffffffff812e2f9d>] do_get_write_access+0x2bd/0x4e0 [<ffffffff812e31e7>] jbd2_journal_get_write_access+0x27/0x40 [<ffffffff812c844b>] __ext4_journal_get_write_access+0x3b/0x80 [<ffffffff81294013>] ext4_free_inode+0x223/0x660 [<ffffffff8129d2ce>] ext4_evict_inode+0x31e/0x4d0 [<ffffffff81228903>] evict+0xa3/0x190 [<ffffffff812291b5>] iput+0xf5/0x1a0 [<ffffffff81224128>] __dentry_kill+0x168/0x1c0 [<ffffffff81224248>] dput+0xc8/0x1b0 [<ffffffff8120e2e2>] __fput+0x172/0x1f0 [<ffffffff8120e3ae>] ____fput+0xe/0x10 [<ffffffff810b3957>] task_work_run+0xb7/0xf0 [<ffffffff81013e37>] do_notify_resume+0x97/0xb0 [<ffffffff81746d22>] int_signal+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff Should I open another ticket for this issue?
libxshmfence-1.2-1.fc21 has been submitted as an update for Fedora 21. https://admin.fedoraproject.org/updates/libxshmfence-1.2-1.fc21
(In reply to Lee from comment #0) > Please see the following Chromium bug, comment #70 for background: > https://code.google.com/p/chromium/issues/detail?id=415681 > > Chromium's GPU process sandbox limits filesystem access to a predetermined > whitelist. libxshmfence needs to create temporary shared memory files and > the location for these files is decided at build time as a config param. > This should be /dev/shm and this is the path Chromium whitelists. On Fedora > builds the shared memory files are being placed in /var/tmp. > > Putting shared memory files in /var/tmp or /tmp isn't the right place for > them. It doesn't seem right to whitelist these extra paths in Chromium when > they should be in /dev/shm. > > Would it possible to change the Fedora build config so these files are > placed more appropriately (in /dev/shm), thus being inline with other > distros and compatible with Chromium. > > Many thanks Just updated it to 1.2 which does not use any filesystem access but just the memfd_create systemcall instead.
Package libxshmfence-1.2-1.fc21: * should fix your issue, * was pushed to the Fedora 21 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing libxshmfence-1.2-1.fc21' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2015-0266/libxshmfence-1.2-1.fc21 then log in and leave karma (feedback).
libxshmfence-1.2-1.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.