Re: Make the git codebase thread-safe
From: David Kastrup <hidden>
Date: 2016-06-15 22:59:53
Stefan Zager [off-list ref] writes:
On Wed, Feb 12, 2014 at 10:50 AM, David Kastrup [off-list ref] wrote:quoted
Really, give the above patch a try. I am taking longer to finish it than anticipated (with a lot due to procrastination but that is, unfortunately, a large part of my workflow), and it's cutting into my "paychecks" (voluntary donations which to a good degree depend on timely and nontrivial progress reports for my freely available work on GNU LilyPond).I will give that a try. How much of a performance improvement have you clocked?
Depends on file type and size. With large files with lots of small changes, performance improvements get more impressive. Some ugly real-world examples are the Emacs repository, src/xdisp.c (performance improvement about a factor of 3), a large file in the style of /usr/share/dict/words clocking in at a factor of about 5. Again, that's with an SSD and ext4 filesystem on GNU/Linux, and there are no improvements in system time (I/O) except for patch 4 of the series which helps perhaps 20% or so. So the benefits of the patch will come into play mostly for big, bad files on Windows: other than that, the I/O time is likely to be the dominant player anyway. If you have benchmarked the stuff, for annoying cases expect I/O time to go down maybe 10-20%, and user time to drop by a factor of 4. Under GNU/Linux, that makes for a significant overall improvement. On Windows, the payback is likely quite less because of the worse I/O performance. Pity. -- David Kastrup