Messages in this thread | | | Date | Fri, 09 May 2008 08:09:34 +0200 | From | Jesper Krogh <> | Subject | Re: Many open/close on same files yeilds "No such file or directory". |
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Andrew Morton wrote: >> My feeling is that the script below may reveal the bug on any "busy" >> volume, where busy is lots of activity in the OS-cache of the volume, >> not on the actual drives. > > By this do you mean that there has to be a lot of other activity on the > system to reproduce it? Stuff which is turning over memory?
Yes, something like that. (sorry for not being able to be more concrete). The applications has "high activity" on a few files, not spread activity throughout the volume.
> Because one possiblity is that the cached dentry got reclaimed by memory > pressure and we have some race bug which causes us to think that the file > doesn't exist.
What can i do to explore this theory? Can I disable caching of dentries and see it go away? Does it fit the pattern that it is only the "open"-syscall that is hit (not read for example)?
> (That still shouldn't happen because the dentry should be marked > recently-accessed, but perhaps the underlying inode gets reclaimed or > something. Grasping at straws here)
When I disabled the NFS-server and rand my "real-world" program on a single processor (make -j 1). It ran through fine. It basically gets around 20 million chunks out of differnet file and assemble the chuncks in a few other files. This processes more or less 5 individual sections, so make can run effectively with a concurrency of 5.
I dont know if there can be any technical reasons for not seeing it on internal attached disks? (other than I just hadn't been able to reproduce the same error conditions there.
Jesper -- Jesper
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