Hi, Hugh, Hugh Dickins <hughd@xxxxxxxxxx> writes: > On Thu, 16 Feb 2017, Tim Chen wrote: >> >> > I do not understand your zest for putting wrappers around every little >> > thing, making it all harder to follow than it need be. Here's the patch >> > I've been running with (but you have a leak somewhere, and I don't have >> > time to search out and fix it: please try sustained swapping and swapoff). >> > >> >> Hugh, trying to duplicate your test case. So you were doing swapping, >> then swap off, swap on the swap device and restart swapping? > > Repeated pair of make -j20 kernel builds in 700M RAM, 1.5G swap on SSD, > 8 cpus; one of the builds in tmpfs, other in ext4 on loop on tmpfs file; > sizes tuned for plenty of swapping but no OOMing (it's an ancient 2.6.24 > kernel I build, modern one needing a lot more space with a lot less in use). > > How much of that is relevant I don't know: hopefully none of it, it's > hard to get the tunings right from scratch. To answer your specific > question: yes, I'm not doing concurrent swapoffs in this test showing > the leak, just waiting for each of the pair of builds to complete, > then tearing down the trees, doing swapoff followed by swapon, and > starting a new pair of builds. > > Sometimes it's the swapoff that fails with ENOMEM, more often it's a > fork during build that fails with ENOMEM: after 6 or 7 hours of load > (but timings show it getting slower leading up to that). /proc/meminfo > did not give me an immediate clue, Slab didn't look surprising but > I may not have studied close enough. Thanks for you information! Memory newly allocated in the mm-swap series are allocated via vmalloc, could you find anything special for vmalloc in /proc/meminfo? Best Regards, Huang, Ying > I quilt-bisected it as far as the mm-swap series, good before, bad > after, but didn't manage to narrow it down further because of hitting > a presumably different issue inside the series, where swapoff ENOMEMed > much sooner (after 25 mins one time, during first iteration the next). > > Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
