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| author |  Joey Hess <joey@kitenet.net> | 2011-04-27 22:10:57 -0400 |
|---|---|---|
| committer | Joey Hess <joey@kitenet.net> | 2011-04-27 23:18:35 -0400 |
| commit | 7a338031933cbba7b021468ee83bb63fb3d6d42a (patch) | |
| tree | 482cf16d493dc1837b0f98223a9353a0fc89ebb8 /debian | |
| parent | 39966ba4eeb6046c511d3f3b630a3ee2ced5019a (diff) | |
Avoid pipeline stall when running git annex drop or fsck on a lot of files.
When it's stalled, there are 3 processes:
git annex
git ls-files
git check-attr
git-annex stalls trying to write to git check-attr, which stalls trying to
write to stdout (read by git-annex).
git ls-files does not seem to be involved directly; I've seen the stall when
it was still streaming out the file list, and after it had exited and
zombified.
The read and write are supposed to be handled by two different threads,
which pipeBoth forks off, thus avoiding deadlock. But it does deadlock.
(Certian signals unblock the deadlock for a while, then it stalls again.)
So, this is another case of WTF is the ghc IO manager doing today?
I avoid the issue by converting the writer to a separate process.
Possibly this was caused by some change in ghc 7 -- I'm offline and cannot
verify now, but I'm sure I used to be able to run git annex drop w/o it
hanging! And the code does not seem to have changed, except for commit
c1dc4079419cff94cca72441d5e67a866110ec7e, which I tried reverting without
success. In fact, I reverted all the way back to 0.20110316 and still
saw the stall.
Update: Minimal test case:
import System.Cmd.Utils
main = do
as <- checkAttr "blah" $ map show [1..100000]
sequence $ map (putStrLn . show) as
checkAttr attr files = do
(_, s) <- pipeBoth "git" params $ unlines files
return $ lines s
where
params = ["check-attr", attr, "--stdin"]
Bug filed on ghc in debian, #624389
Diffstat (limited to 'debian')
| -rw-r--r-- | debian/changelog | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/debian/changelog b/debian/changelog index 991c9e0bb..a69f03f5e 100644 --- a/debian/changelog +++ b/debian/changelog @@ -4,6 +4,8 @@ git-annex (0.20110426) UNRELEASED; urgency=low Debian stable. * Added rsync special remotes. This could be used, for example, to store annexed content on rsync.net (encrypted naturally). Or anywhere else. + * Bugfix: Avoid pipeline stall when running git annex drop or fsck on a + lot of files. Possibly only occured with ghc 7. -- Joey Hess <joeyh@debian.org> Tue, 26 Apr 2011 11:23:54 -0400 |