Mercurial > hg
view tests/test-merge9.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 | 8e6d5b7317e6 |
children | 41ef02ba329b |
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test that we don't interrupt the merge session if a file-level merge failed $ hg init repo $ cd repo $ echo foo > foo $ echo a > bar $ hg ci -Am 'add foo' adding bar adding foo $ hg mv foo baz $ echo b >> bar $ echo quux > quux1 $ hg ci -Am 'mv foo baz' adding quux1 $ hg up -qC 0 $ echo >> foo $ echo c >> bar $ echo quux > quux2 $ hg ci -Am 'change foo' adding quux2 created new head test with the rename on the remote side $ HGMERGE=false hg merge merging bar merging foo and baz to baz merging bar failed! 1 files updated, 1 files merged, 0 files removed, 1 files unresolved use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon [1] $ hg resolve -l U bar R baz test with the rename on the local side $ hg up -C 1 3 files updated, 0 files merged, 1 files removed, 0 files unresolved $ HGMERGE=false hg merge merging bar merging baz and foo to baz merging bar failed! 1 files updated, 1 files merged, 0 files removed, 1 files unresolved use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon [1] show unresolved $ hg resolve -l U bar R baz unmark baz $ hg resolve -u baz show $ hg resolve -l U bar U baz $ hg st M bar M baz M quux2 ? bar.orig re-resolve baz $ hg resolve baz merging baz and foo to baz after resolve $ hg resolve -l U bar R baz resolve all warning $ hg resolve abort: no files or directories specified (use --all to re-merge all unresolved files) [255] resolve all $ hg resolve -a merging bar warning: conflicts while merging bar! (edit, then use 'hg resolve --mark') [1] after $ hg resolve -l U bar R baz $ cd ..