Re: [PATCH 0/5] Avoid file descriptor exhaustion in ref_transaction_commit()
Jeff King writes: > Stefan's patch is just in pu at this point, right? I do not think there > is any rushing/release concern. It is too late for either to be in > v2.4.0, so the only decision is whether to aim for "master" or "maint". > To me, they both seem to be in the same ballpark as far as risking a > regression. The series builds on c1f0ca9 that is on 2.4.0-rc2, so we would need to wiggle things around to apply to older codebase if we want to fix the "too many open file descriptor" issue on older maintenance releases for "update-ref --stdin". I personally feel that it is OK to ship v2.4.0 without the fix, leaving "push --atomic" broken, and fix it in v2.4.1, but I kinda prefer that the final fix to be applicable for older maintenance releases, at least to 2.3.x track, if not 2.2.x track. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Avoid file descriptor exhaustion in ref_transaction_commit()
Michael Haggerty writes: > In ref_transaction_commit(), close the reference lockfiles immediately > to avoid keeping too many file descriptors open at a time. This is > pretty easy, because in the first loop (where we create the locks) we > already know what, if anything, has to be written into the lockfile. Nicely analysed and beautifully executed. I like it. > This patch series applies on top of Stefan's > > c1f0ca9 refs.c: remove lock_fd from struct ref_lock (2015-04-16) > > and it fixes two tests that Stefan introduced earlier in that series. Thanks. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Avoid file descriptor exhaustion in ref_transaction_commit()
On Fri, Apr 24, 2015 at 10:26 AM, Jeff King wrote: > On Fri, Apr 24, 2015 at 01:35:44PM +0200, Michael Haggerty wrote: > >> In ref_transaction_commit(), close the reference lockfiles immediately >> to avoid keeping too many file descriptors open at a time. This is >> pretty easy, because in the first loop (where we create the locks) we >> already know what, if anything, has to be written into the lockfile. >> So write it and close the lockfile immediately. In the second loop, >> rename the lockfiles for reference updates into place, and in the >> cleanup loop, unlock any references that are still locked (i.e., those >> that were only being verified or deleted). >> >> I think this is a cleaner solution than Stefan's approach [1] of >> closing and reopening fds based on an estimate of how many fds we can >> afford to waste--we only need a single file descriptor at a time, and >> we never have to close then reopen a lockfile. But it is a bit more >> intrusive, so it might still be preferable to use Stefan's approach >> for release 2.4.0, if indeed any fix for this problem is still being >> considered for that release. > > I like this approach much better. It seems like the best of all worlds > (same performance, and we don't have to worry about whether and when to > close lockfiles). I would have guessed this approach to take more work to do it right. Thanks Michael for tackling the problem in an elegant way! > > Stefan's patch is just in pu at this point, right? I do not think there > is any rushing/release concern. Yeah it's in pu, so it's easy to remove. > It is too late for either to be in > v2.4.0, so the only decision is whether to aim for "master" or "maint". > To me, they both seem to be in the same ballpark as far as risking a > regression. > > -Peff Thanks, Stefan -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 0/5] Avoid file descriptor exhaustion in ref_transaction_commit()
On Fri, Apr 24, 2015 at 01:35:44PM +0200, Michael Haggerty wrote: > In ref_transaction_commit(), close the reference lockfiles immediately > to avoid keeping too many file descriptors open at a time. This is > pretty easy, because in the first loop (where we create the locks) we > already know what, if anything, has to be written into the lockfile. > So write it and close the lockfile immediately. In the second loop, > rename the lockfiles for reference updates into place, and in the > cleanup loop, unlock any references that are still locked (i.e., those > that were only being verified or deleted). > > I think this is a cleaner solution than Stefan's approach [1] of > closing and reopening fds based on an estimate of how many fds we can > afford to waste--we only need a single file descriptor at a time, and > we never have to close then reopen a lockfile. But it is a bit more > intrusive, so it might still be preferable to use Stefan's approach > for release 2.4.0, if indeed any fix for this problem is still being > considered for that release. I like this approach much better. It seems like the best of all worlds (same performance, and we don't have to worry about whether and when to close lockfiles). Stefan's patch is just in pu at this point, right? I do not think there is any rushing/release concern. It is too late for either to be in v2.4.0, so the only decision is whether to aim for "master" or "maint". To me, they both seem to be in the same ballpark as far as risking a regression. -Peff -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 0/5] Avoid file descriptor exhaustion in ref_transaction_commit()
In ref_transaction_commit(), close the reference lockfiles immediately to avoid keeping too many file descriptors open at a time. This is pretty easy, because in the first loop (where we create the locks) we already know what, if anything, has to be written into the lockfile. So write it and close the lockfile immediately. In the second loop, rename the lockfiles for reference updates into place, and in the cleanup loop, unlock any references that are still locked (i.e., those that were only being verified or deleted). I think this is a cleaner solution than Stefan's approach [1] of closing and reopening fds based on an estimate of how many fds we can afford to waste--we only need a single file descriptor at a time, and we never have to close then reopen a lockfile. But it is a bit more intrusive, so it might still be preferable to use Stefan's approach for release 2.4.0, if indeed any fix for this problem is still being considered for that release. This patch series applies on top of Stefan's c1f0ca9 refs.c: remove lock_fd from struct ref_lock (2015-04-16) and it fixes two tests that Stefan introduced earlier in that series. It is also available from my GitHub account: https://github.com/mhagger/git branch close-ref-locks-promptly Michael [1] http://article.gmane.org/gmane.comp.version-control.git/267548 Michael Haggerty (5): write_ref_to_lockfile(): new function, extracted from write_ref_sha1() commit_ref_update(): new function, extracted from write_ref_sha1() write_ref_sha1(): inline function at callers ref_transaction_commit(): remove the local flags variables ref_transaction_commit(): only keep one lockfile open at a time refs.c| 107 ++ t/t1400-update-ref.sh | 4 +- 2 files changed, 75 insertions(+), 36 deletions(-) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
