On Tue, 2014-06-17 at 12:27 -0500, Jack Miller wrote: > [ RESEND note: Adding relevant CCs, fixed a couple of typos in commit message, > patches unchanged. Original intro follows. ] > > All - > > This is small set of patches our team has had kicking around for a few > versions > internally that fixes tasks getting hung on shm_exit when there are many > threads hammering it at once. > > Anton wrote a simple test to cause the issue: > > http://ozlabs.org/~anton/junkcode/bust_shm_exit.c
I'm actually in the process of adding shm microbenchmarks to perf-bench so I might steal this :-) > > Before applying this patchset, this test code will cause either hanging > tracebacks or pthread out of memory errors. Are you seeing this issue in any real world setups? While the program does stress the path you mention quite well, I fear it is very unrealistic... how many shared mem segments do real applications actually use/create for scaling issues to appear? I normally wouldn't mind optimizing synthetic cases like this, but a quick look at patch 1/3 shows that we're adding an extra overhead (16 bytes) in the task_struct. In any case, I will take a closer look at the set. Thanks, Davidlohr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
