On Sun, Aug 25, 2013 at 04:28:37PM +0200, Peter Zijlstra wrote: > and a function (or function-graph) > trace for when this happens?
Unfortunately I could not make trace. First when migration threads start to eat CPUs and when I turn on trace: # echo function > current_tracer # echo 1 > tracing_on then server is down at once. LA comes up to several thousands, it stops to receive commands. Sometimes I even have to reboot it. And second when I manage to get trace then it shows little useful data. https://www.dropbox.com/s/kxgwr9fuckddtgf/trace.txt.gz Probably this junk appears from grsec patch? And I don't see migration threads in it. > Perhaps perf top -p <pick-a-thread> while the problem is happening will > show something. Also "perf top" doesn't show anything. It gives same values when migration threads eat CPUs and when everything is OK on server. ========================================= PerfTop: 68932 irqs/sec kernel:60.3% exact: 0.0% [4000Hz cycles], (all, 32 CPUs) --------------------------------------------------------------------------------- 64.11% [netconsole] [k] 0xffffffff81000de3 34.19% [unknown] [.] 0x0000000000585c45 0.40% libc-2.15.so [.] 0x0000000000124b10 0.23% perf [.] 0x000000000004df4f 0.14% ld-2.15.so [.] 0x00000000000183e7 0.08% libc-2.15.so [.] _nss_files_parse_grent 0.06% libc-2.15.so [.] _nss_files_parse_pwent 0.04% libc-2.15.so [.] memchr 0.04% php-cgi [.] match 0.03% libcrypt-2.15.so [.] 0x0000000000004eab 0.03% bash [.] 0x000000000001fe5a 0.02% libc-2.15.so [.] _IO_getline_info 0.02% php-cgi [.] php_pcre_exec 0.02% libc-2.15.so [.] _dl_addr 0.02% eaccelerator.so [.] eaccelerator_crc32 0.02% php-cgi [.] zend_hash_quick_find 0.02% libnss_compat-2.15.so [.] 0x00000000000055f1 0.01% php-cgi [.] zendparse 0.01% libc-2.15.so [.] fgets_unlocked 0.01% libnss_compat-2.15.so [.] _nss_compat_initgroups_dyn ========================================= Now server is more loaded and eating CPUs by migration threads happens more often and it lasts longer. -- BRGDS. Alexey Vlasov. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
