chromium port causing massive I/O faults
Alexander Best
arundel at freebsd.org
Wed Jul 27 09:38:57 UTC 2011
On Wed Jul 27 11, René Ladan wrote:
> 2011/7/27 Alexander Best <arundel at freebsd.org>:
> > On Wed Jul 27 11, René Ladan wrote:
> >> 2011/7/27 Gleb Kurtsou <gleb.kurtsou at gmail.com>:
> >> > On (27/07/2011 00:48), Alexander Best wrote:
> >> >> On Mon Jul 25 11, Matthias Andree wrote:
> >> >> > Am 25.07.2011 09:21, schrieb Alexander Best:
> >> >> > > On Mon Jul 25 11, Adrian Chadd wrote:
> >> >> > >> Is it perhaps doing disk IO using mmap?
> >> >> > >
> >> >> > > how can i check, whether that's the case or not?
> >> >> >
> >> >> > Use truss(1) for instance.
> >> >> >
> >> >> > However, unless there are *practical* problems, a high number of page
> >> >> > faults is not an indication for problems. Although it may sound scary,
> >> >> > page faults are a feature of the memory management.
> >> >>
> >> >> unfortunately truss(1) is crashing chromium :( i opened up a new thread
> >> >> reagarding this issue on freebsd-current at .
> >> > Could you try ktrace? It works for me
> >> >
> >> >> another thing i noticed is the increase in system calls caused by chromium.
> >> >> let's have a look at hub.freebsd.org:
> >> >>
> >> >> uptime = 149 days
> >> >>
> >> >> and 'vmstat -s' reports:
> >> >>
> >> >> 2168697753 cpu context switches
> >> >> 2266220366 device interrupts
> >> >> 2902880931 software interrupts
> >> >> 3779075897 traps
> >> >> 902107847 system calls
> >> >>
> >> >> now on my box:
> >> >>
> >> >> uptime = 2 days
> >> >>
> >> >> and 'vmstat -s' reports:
> >> >>
> >> >> 1155995386 cpu context switches
> >> >> 164577882 device interrupts
> >> >> 189456976 software interrupts
> >> >> 137007580 traps
> >> >> 2178434582 system calls
> >> > About 2.5k syscalls with chrome + a lot of other stuff running. 1.5k
> >> > without chrome.
> >> >
> >> > Looks like there is a lot of clock_gettime and gettimeofday syscalls.
> >> > ~ % kdump -m 1 -f ktrace.out | grep 'CALL .*gettime' | wc -l
> >> > 24343
> >> >
> >> > ~ % kdump -E -m 1 -f ktrace.out | grep 'CALL .*gettime' | tail -20
> >> > 12747 chrome 15.077376 CALL gettimeofday(0x7fffff7f9630,0x7fffff7f9640)
> >> > 12747 chrome 15.077396 CALL clock_gettime(0x4,0x7fffffbfb6f0)
> >> > 12747 chrome 15.077497 CALL gettimeofday(0x7fffffbfb650,0x7fffffbfb660)
> >> > 12747 chrome 15.077609 CALL gettimeofday(0x7fffffbfb650,0x7fffffbfb660)
> >> > 12747 chrome 15.077723 CALL gettimeofday(0x7fffffbfb650,0)
> >> > 12747 chrome 15.077845 CALL clock_gettime(0,0x7fffffbfb2b0)
> >> > 12747 chrome 15.078337 CALL clock_gettime(0x4,0x7fffff9fa630)
> >> > 12747 chrome 15.078544 CALL clock_gettime(0x4,0x7fffff9fa650)
> >> > 12747 chrome 15.078587 CALL clock_gettime(0x4,0x7fffff9fa650)
> >> > 12747 chrome 15.078632 CALL clock_gettime(0x4,0x7fffff9fa650)
> >> > 12747 chrome 15.078674 CALL clock_gettime(0x4,0x7fffff9fa650)
> >> > 12747 chrome 15.082803 CALL gettimeofday(0x7ffffedd3630,0x7ffffedd3640)
> >> > 12747 chrome 15.084644 CALL gettimeofday(0x7fffffbfb650,0x7fffffbfb660)
> >> > 12747 chrome 15.084746 CALL clock_gettime(0x4,0x7fffffbfb670)
> >> > 12747 chrome 15.084815 CALL clock_gettime(0x4,0x7fffffbfb670)
> >> > 12747 chrome 15.086620 CALL gettimeofday(0x7ffffefd4650,0x7ffffefd4660)
> >> > 12747 chrome 15.086736 CALL clock_gettime(0x4,0x7ffffefd4670)
> >> > 12747 chrome 15.086815 CALL clock_gettime(0x4,0x7ffffefd4670)
> >> > 12747 chrome 15.098315 CALL gettimeofday(0x7fffffffafe0,0x7fffffffaff0)
> >> > 12747 chrome 15.098680 CALL clock_gettime(0x4,0x7fffffffb250)
> >> >
> >> > Some work was done by kib@ to create a kernel page strong current time
> >> > and other misc info to eliminate gettimeofday kind syscalls. Bits of it
> >> > were commited but I'm not sure if it was finished.
> >> > But anyway calling gettimeofday hundreds of times per second is a chrome
> >> > bug.
...also the number of context switches is very high. the following 'vmstat -s'
output was taken after only 32 minutes of uptime and chromium running for ~ 10
minutes:
39775038 cpu context switches
1716910 device interrupts
1707161 software interrupts
1764371 traps
57319358 system calls
15 kernel threads created
2120 fork() calls
11 vfork() calls
25 rfork() calls
0 swap pager pageins
0 swap pager pages paged in
0 swap pager pageouts
0 swap pager pages paged out
71184 vnode pager pageins
102181 vnode pager pages paged in
13321 vnode pager pageouts
67437 vnode pager pages paged out
0 page daemon wakeups
0 pages examined by the page daemon
4662 pages reactivated
93964 copy-on-write faults
274 copy-on-write optimized faults
358563 zero fill pages zeroed
319 zero fill pages prezeroed
302 intransit blocking page faults
740518 total VM faults taken
0 pages affected by kernel thread creation
1130760 pages affected by fork()
17316 pages affected by vfork()
22319 pages affected by rfork()
7162 pages cached
693935 pages freed
0 pages freed by daemon
396060 pages freed by exiting processes
34690 pages active
88551 pages inactive
164 pages in VM cache
76703 pages wired down
301738 pages free
4096 bytes per page
426219 total name lookups
cache hits (87% pos + 2% neg) system 0% per-directory
deletions 2%, falsehits 0%, toolong 0%
with chromium running:
otaku% vmstat -s|grep "context switches"; sleep 1; vmstat -s|grep "context switches"
39604188 cpu context switches
39610679 cpu context switches
without:
otaku% vmstat -s|grep "context switches"; sleep 1; vmstat -s|grep "context switches"
39722188 cpu context switches
39722998 cpu context switches
cheers.
alex
> >> >
> >> > FreeBSD 9.0-CURRENT #2 r224003+777e962: Thu Jul 14 13:04:55 EEST 2011
> >> > chromium-11.0.696.57_1
> >> ^^^^^^^^^^^^^
> >> Can you retry with an up-to-date version of www/chromium? The
> >> codebase of chromium
> >> changes quite fast so not using the latest version in ports might
> >> render obsolete (and
> >> upstream unsupported) results.
> >
> > my tests were done with chromium-12.0.742.124 btw.
> >
> Ok, I'll do some tests with the beta version from the chruetertee
> repository (13.0.782.99).
> >>
> >> René
> >> --
> >> http://www.rene-ladan.nl/
> >
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