mbthomas added a comment.
In https://phab.mercurial-scm.org/D477#7739, @indygreg wrote: > Do you know what happens with the underlying file descriptor when it is memory mapped? If an fd stays open, that could lead to fd exhaustion. This can be mitigated by only using mmap for certain files (minimize size, changelog, etc). It's something I'd like an answer to before this is queued. The fd remains open. (Actually, the fd is dup'd and the original one is closed. The dup remains open.) For this reason I'm going to restrict it to changelog and manifest indexes only, as those are the ones that are known to grow big. INLINE COMMENTS > simonfar wrote in revlog.py:343 > Is there any reason for `mmapread` to not immediately wrap the data in a > `util.buffer` for you? I took it from Jun's original patch, but I think it's simply separation of responsibilities. `util.mmapread`'s purpose is to wrap `mmap(... ACCESS_READ)` and handle the case where the file is empty, which normally fails. REPOSITORY rHG Mercurial REVISION DETAIL https://phab.mercurial-scm.org/D477 To: mbthomas, #fbhgext, indygreg, #hg-reviewers, durin42 Cc: quark, durin42, simonfar, mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
