On Sat, 2011-06-18 at 13:04 +1000, Cameron Simpson wrote: > On 17Jun2011 20:12, Kevin Martin <kevintm@xxxxxxxxxxxxx> wrote: > | On 06/17/2011 07:16 PM, Patrick O'Callaghan wrote: > | > On Fri, 2011-06-17 at 15:03 -0700, Jonathan Ryshpan wrote: > | >> Investigating a hanging instance of googleearth (wich process number > | >> 3110), I noticed that it's possible to > | >> cd /proc/3110 > | >> while on the other hand > | >> ls /proc > | >> does not show 3110 as being in the proc directory. > | >> > | >> Any ideas what's going on? > | > I can't imagine how that could happen, unless the directory entry > | > disappeared between you doing the cd and the ls, perhaps because the > | > process terminated. OTOH is you can reproduce this reliably, it could > | > merit a Bugzilla report. > | > > | > poc > | > > | > | It's a kernel / system call bug somewhere. We ran (the company I work for) into this exact bug in our software application (a > | monitoring tool for monitoring system health, applications, doing log file scraping). Monitoring of processes worked on AIX, > | Solaris, etc. but with a version of Linux starting about 3-4 years ago, it stopped working reliably. It has to do with a system > | call and I can't remember at this time what it was. I'll look back on our application fixes and see if I can come up with what the > | fix was. It might absolutely merit a Bugzilla. > > [speculation...] > It might be raciness in the readdir calls. I'd imagine /proc is rather > volatile becuase of all the PIDs. Readdir has always been a weak link in > the directory listing stuff (not just Linux, though it or GNU ls might > be particularly prone to exposing it). > [/speculation] The problem might be similar to this: http://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.18/2.6.18-mm2/broken-out/proc-readdir-race-fix-take-3.patch poc -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
