Mercurial > hg
view tests/test-rename-after-merge.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 | f2719b387380 |
children | eb586ed5d8ce |
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Issue746: renaming files brought by the second parent of a merge was broken. Create source repository: $ hg init t $ cd t $ echo a > a $ hg ci -Am a adding a $ cd .. Fork source repository: $ hg clone t t2 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd t2 $ echo b > b $ hg ci -Am b adding b Update source repository: $ cd ../t $ echo a >> a $ hg ci -m a2 Merge repositories: $ hg pull ../t2 pulling from ../t2 searching for 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 st M b Rename b as c: $ hg mv b c $ hg st A c R b Rename back c as b: $ hg mv c b $ hg st M b $ cd .. Issue 1476: renaming a first parent file into another first parent file while none of them belong to the second parent was broken $ hg init repo1476 $ cd repo1476 $ echo a > a $ hg ci -Am adda adding a $ echo b1 > b1 $ echo b2 > b2 $ hg ci -Am changea adding b1 adding b2 $ hg up -C 0 0 files updated, 0 files merged, 2 files removed, 0 files unresolved $ echo c1 > c1 $ echo c2 > c2 $ hg ci -Am addcandd adding c1 adding c2 created new head Merge heads: $ hg merge 2 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg mv -Af c1 c2 Commit issue 1476: $ hg ci -m merge $ hg log -r tip -C -v | grep copies copies: c2 (c1) $ hg rollback repository tip rolled back to revision 2 (undo commit) working directory now based on revisions 2 and 1 $ hg up -C . 2 files updated, 0 files merged, 2 files removed, 0 files unresolved Merge heads again: $ hg merge 2 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg mv -Af b1 b2 Commit issue 1476 with a rename on the other side: $ hg ci -m merge $ hg log -r tip -C -v | grep copies copies: b2 (b1) $ cd ..