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Monday, May 6th, 2019
| Time |
Event |
| 1:14a |
| | 12:45p |
Firefox 66.0.4 released
There is a new Firefox browser release available; its main claim to fame is
that it has a fix for the certificate issue that disabled all extensions. | | 2:31p |
Security updates for Monday
Security updates have been issued by Debian (jquery, librecad, and phpbb3), Fedora (bubblewrap, java-11-openjdk, libvirt, openssh, and pacemaker), Mageia (virtualbox), openSUSE (chromium, ImageMagick, and java-11-openjdk), and SUSE (openssl-1_1). | | 5:15p |
[$] Transparent huge pages, NUMA locality, and performance regressions
Sometimes, the kernel's no-regression rule may not have the desired
result. Andrea Arcangeli led a session at the 2019 Linux Storage,
Filesystem, and Memory-Management Summit to make the point that the recent
reversion of a fix after a performance regression was reported has led to
worse performance overall — with, as is his wont, a lot of technical
information to back up that point. With a wider understanding of what is at
stake here, he hopes, the reversion can itself be reverted. | | 5:20p |
[$] NUMA nodes for persistent-memory management
While persistent memory is normally valued for its persistence, there is
also a subcurrent of interest in using it in settings where persistence is
not important. In particular, the fact that this memory is relatively
inexpensive makes it appealing to use instead of ordinary RAM in
budget-conscious settings. At the 2019 Linux Storage, Filesystem, and
Memory-Management Summit, two sessions in the memory-management track
looked at how the kernel's NUMA mechanism could be pressed into service to
manage non-persistent uses of persistent memory. | | 5:47p |
[$] Issues around discard
In a combined filesystem and storage session at the 2019 Linux Storage, Filesystem,
and Memory-Management Summit (LSFMM), Dennis Zhou wanted to talk
about discard, which is the process of sending commands
(e.g. TRIM) to block devices to indicate
blocks that are no longer in use. Discard is a "serious black box", he
said; it is a third way to interact with a drive, but Linux developers have
no real insight into what its actual effects will be. That can lead to
performance and other problems. | | 8:24p |
[$] Improving fget() performance
The performance of the fget() function in the kernel was the topic
of a discussion led by Dave Watson at the 2019 Linux Storage, Filesystem,
and Memory-Management Summit (LSFMM).
fget()
is used to take a reference to a
file (i.e. bump a reference count), based on its file descriptor, and to
return the struct file pointer for it; references are dropped with
fput().
Some recent profiling at Watson's
employer, Facebook, found the function to be taking a sizable portion of
the CPU time for some applications, so he wanted to talk about some of the
things he has tried to make that situation better. |
|