On Thu, Sep 28, 2017 at 9:19 PM, Ruslan Ruslichenko -X (rruslich - GLOBALLOGIC INC at Cisco) <rruslich@xxxxxxxxx> wrote: > Hi Johannes, > > Hopefully I was able to rebase the patch on top v4.9.26 (latest supported > version by us right now) > and test a bit. > The overall idea definitely looks promising, although I have one question on > usage. > Will it be able to account the time which processes spend on handling major > page faults > (including fs and iowait time) of refaulting page? > > As we have one big application which code space occupies big amount of place > in page cache, > when the system under heavy memory usage will reclaim some of it, the > application will > start constantly thrashing. Since it code is placed on squashfs it spends > whole CPU time > decompressing the pages and seem memdelay counters are not detecting this > situation. > Here are some counters to indicate this: > > 19:02:44 CPU %user %nice %system %iowait %steal %idle > 19:02:45 all 0.00 0.00 100.00 0.00 0.00 0.00 > > 19:02:44 pgpgin/s pgpgout/s fault/s majflt/s pgfree/s pgscank/s > pgscand/s pgsteal/s %vmeff > 19:02:45 15284.00 0.00 428.00 352.00 19990.00 0.00 0.00 > 15802.00 0.00 > > And as nobody actively allocating memory anymore looks like memdelay > counters are not > actively incremented: > > [:~]$ cat /proc/memdelay > 268035776 > 6.13 5.43 3.58 > 1.90 1.89 1.26 > > Just in case, I have attached the v4.9.26 rebased patched. > Looks like this 4.9 version does not contain the accounting in lock_page. -- 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>
