Mercurial > hg
view tests/test-issue586.t @ 30212:260af19891f2
changegroup: increase write buffer size to 128k
By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.
This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.
It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.
When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).
This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 16 Oct 2016 13:35:23 -0700 |
parents | 4591cd6b6794 |
children | eb586ed5d8ce |
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Issue586: removing remote files after merge appears to corrupt the dirstate $ hg init a $ cd a $ echo a > a $ hg ci -Ama adding a $ hg init ../b $ cd ../b $ echo b > b $ hg ci -Amb adding b $ hg pull -f ../a pulling from ../a searching for changes warning: repository is unrelated requesting all changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg merge 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg rm -f a $ hg ci -Amc $ hg st -A C b $ cd .. Issue1433: Traceback after two unrelated pull, two move, a merge and a commit (related to issue586) create test repos $ hg init repoa $ touch repoa/a $ hg -R repoa ci -Am adda adding a $ hg init repob $ touch repob/b $ hg -R repob ci -Am addb adding b $ hg init repoc $ cd repoc $ hg pull ../repoa pulling from ../repoa requesting all changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (run 'hg update' to get a working copy) $ hg update 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ mkdir tst $ hg mv * tst $ hg ci -m "import a in tst" $ hg pull -f ../repob pulling from ../repob searching for changes warning: repository is unrelated requesting all changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) merge both repos $ hg merge 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ mkdir src move b content $ hg mv b src $ hg ci -m "import b in src" $ hg manifest src/b tst/a $ cd ..