>>> Vladislav Bogdanov <[email protected]> schrieb am 08.09.2015 um 14:05 in Nachricht <[email protected]>: > Hi, > > just discovered very interesting issue. > If there is a system user with very big UID (80000002 in my case), > then crm_report (actually 'grep' it runs) consumes too much RAM. > > Relevant part of the process tree at that moment looks like (word-wrap off): > USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND > ... > root 25526 0.0 0.0 106364 636 ? S 12:37 0:00 \_ > /bin/sh /usr/sbin/crm_report --dest=/var/log/crm_report -f 0000-01-01 00:00:00 > root 25585 0.0 0.0 106364 636 ? S 12:37 0:00 > \_ bash /var/log/crm_report/collector > root 25613 0.0 0.0 106364 152 ? S 12:37 0:00 > \_ bash /var/log/crm_report/collector > root 25614 0.0 0.0 106364 692 ? S 12:37 0:00 > \_ bash /var/log/crm_report/collector > root 27965 4.9 0.0 100936 452 ? S 12:38 0:01 > | \_ cat /var/log/lastlog > root 27966 23.0 82.9 3248996 1594688 ? D 12:38 0:08 > | \_ grep -l -e Starting Pacemaker > root 25615 0.0 0.0 155432 600 ? S 12:37 0:00 > \_ sort -u > > ls -ls /var/log/lastlog shows: > 40 -rw-r--r--. 1 root root 23360000876 Sep 8 04:36 /var/log/lastlog > > That is sparse binary file, which consumes only 40k of disk space. > At the same time its size is 23GB, and grep takes all the RAM trying to > grep a string from a 23GB of mostly zeroes without new-lines. > > I believe this is worth fixing,
I guess the UID value is used as offset in the lastlog file (which is OK). When reading such a sparse file, the filesystem should simply deliver zero blocks to grep. As grep is designed to read from streads there is not much you can do against reading all these zeros, I guess. Also an mmap based solution might exceed the virtual address space, especially for 32-bit systems. BTW: Did you try "last Pacemaker"? I could only test with "last reboot" here... Regards, Ulrich > > Thank you, > Vladislav > > _______________________________________________ > Users mailing list: [email protected] > http://clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org _______________________________________________ Users mailing list: [email protected] http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
