Mercurial > hg-stable
view tests/test-up-local-change.t @ 26379:39d643252b9f
revlog: use existing file handle when reading during _addrevision
_addrevision() may need to read from revlogs as part of computing
deltas. Previously, we would flush existing file handles and open
a new, short-lived file handle to perform the reading.
If we have an existing file handle, it seems logical to reuse it
for reading instead of opening a new file handle. This patch
makes that the new behavior.
After this patch, revlog files are only reopened when adding
revisions if the revlog is switched from inline to non-inline.
On Linux when unbundling a bundle of the mozilla-central repo, this
patch has the following impact on system call counts:
Call Before After Delta
write 827,639 673,390 -154,249
open 700,103 684,089 -16,014
read 74,489 74,489 0
fstat 493,924 461,896 -32,028
close 249,131 233,117 -16,014
stat 242,001 242,001 0
lstat 18,676 18,676 0
lseek 20,268 20,268 0
ioctl 14,652 13,173 -1,479
TOTAL 3,180,758 2,930,679 -250,079
It's worth noting that many of the open() calls fail due to missing
files. That's why there are many more open() calls than close().
Despite the significant system call reduction, this change does not
seem to have a significant performance impact on Linux.
On Windows 10 (not a VM, on a SSD), this patch appears to reduce
unbundle time for mozilla-central from ~960s to ~920s. This isn't
as significant as I was hoping. But a decrease it is nonetheless.
Still, Windows unbundle performance is still >2x slower than Linux.
Despite the lack of significant gains, fewer system calls is fewer
system calls. If nothing else, this will narrow the focus of potential
areas to optimize in the future.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 27 Sep 2015 16:08:18 -0700 |
parents | bd625cd4e5e7 |
children | a5ff66e6d77a |
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$ HGMERGE=true; export HGMERGE $ hg init r1 $ cd r1 $ echo a > a $ hg addremove adding a $ hg commit -m "1" $ hg clone . ../r2 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd ../r2 $ hg up 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo abc > a $ hg diff --nodates diff -r c19d34741b0a a --- a/a +++ b/a @@ -1,1 +1,1 @@ -a +abc $ cd ../r1 $ echo b > b $ echo a2 > a $ hg addremove adding b $ hg commit -m "2" $ cd ../r2 $ hg -q pull ../r1 $ hg status M a $ hg parents changeset: 0:c19d34741b0a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 1 $ hg --debug up searching for copies back to rev 1 unmatched files in other: b resolving manifests branchmerge: False, force: False, partial: False ancestor: c19d34741b0a, local: c19d34741b0a+, remote: 1e71731e6fbb preserving a for resolve of a b: remote created -> g getting b a: versions differ -> m picked tool 'true' for a (binary False symlink False) merging a my a@c19d34741b0a+ other a@1e71731e6fbb ancestor a@c19d34741b0a launching merge tool: true *$TESTTMP/r2/a* * (glob) merge tool returned: 0 1 files updated, 1 files merged, 0 files removed, 0 files unresolved $ hg parents changeset: 1:1e71731e6fbb tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 2 $ hg --debug up 0 resolving manifests branchmerge: False, force: False, partial: False ancestor: 1e71731e6fbb, local: 1e71731e6fbb+, remote: c19d34741b0a preserving a for resolve of a b: other deleted -> r removing b a: versions differ -> m picked tool 'true' for a (binary False symlink False) merging a my a@1e71731e6fbb+ other a@c19d34741b0a ancestor a@1e71731e6fbb launching merge tool: true *$TESTTMP/r2/a* * (glob) merge tool returned: 0 0 files updated, 1 files merged, 1 files removed, 0 files unresolved $ hg parents changeset: 0:c19d34741b0a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 1 $ hg parents changeset: 0:c19d34741b0a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 1 $ hg --debug up searching for copies back to rev 1 unmatched files in other: b resolving manifests branchmerge: False, force: False, partial: False ancestor: c19d34741b0a, local: c19d34741b0a+, remote: 1e71731e6fbb preserving a for resolve of a b: remote created -> g getting b a: versions differ -> m picked tool 'true' for a (binary False symlink False) merging a my a@c19d34741b0a+ other a@1e71731e6fbb ancestor a@c19d34741b0a launching merge tool: true *$TESTTMP/r2/a* * (glob) merge tool returned: 0 1 files updated, 1 files merged, 0 files removed, 0 files unresolved $ hg parents changeset: 1:1e71731e6fbb tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 2 $ hg -v history changeset: 1:1e71731e6fbb tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 files: a b description: 2 changeset: 0:c19d34741b0a user: test date: Thu Jan 01 00:00:00 1970 +0000 files: a description: 1 $ hg diff --nodates diff -r 1e71731e6fbb a --- a/a +++ b/a @@ -1,1 +1,1 @@ -a2 +abc create a second head $ cd ../r1 $ hg up 0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo b2 > b $ echo a3 > a $ hg addremove adding b $ hg commit -m "3" created new head $ cd ../r2 $ hg -q pull ../r1 $ hg status M a $ hg parents changeset: 1:1e71731e6fbb user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 2 $ hg --debug up abort: uncommitted changes (commit and merge, or update --clean to discard changes) [255] test conflicting untracked files $ hg up -qC 0 $ echo untracked > b $ hg st ? b $ hg up 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] $ rm b test conflicting untracked ignored file $ hg up -qC 0 $ echo ignored > .hgignore $ hg add .hgignore $ hg ci -m 'add .hgignore' created new head $ echo ignored > ignored $ hg add ignored $ hg ci -m 'add ignored file' $ hg up -q 'desc("add .hgignore")' $ echo untracked > ignored $ hg st $ hg up 'desc("add ignored file")' ignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] test a local add $ cd .. $ hg init a $ hg init b $ echo a > a/a $ echo a > b/a $ hg --cwd a commit -A -m a adding a $ cd b $ hg add a $ hg pull -u ../a pulling from ../a requesting all changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg st $ cd ..