[Bug 579901] New: One of n CPUs idle, if one process with nice 0 and n-1 processes with nice 19
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c0 Summary: One of n CPUs idle, if one process with nice 0 and n-1 processes with nice 19 Classification: openSUSE Product: openSUSE 11.1 Version: Final Platform: x86-64 OS/Version: openSUSE 11.1 Status: NEW Severity: Normal Priority: P5 - None Component: Kernel AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: b.willenberg@tu-bs.de QAContact: qa@suse.de Found By: --- Blocker: --- Created an attachment (id=342412) --> (http://bugzilla.novell.com/attachment.cgi?id=342412) system information about my tested systems User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.17) Gecko/2009122200 SUSE/3.0.17-0.1.1 Firefox/3.0.17 On a system with n CPUs, n processes running at 100% CPU, all nice 19. If one of these processes is reniced to 0, one CPU becomes idle (seems to be random, which CPU becomes idle). This only occurs on my XEONs with two dualcore CPUs and on the XEONS with two quadcore CPUs. This does _not_ occur on my single quadcore Core i5 750. => bug might occur on systems with two CPUs or on systems with XEONs? Reproducible: Always Steps to Reproduce: 1. If n CPUs are available, start n processes, each using 100% CPU time. E.g. run bc with "scale=10^6; sqrt(2)" 2. start top, renice all bcs to nice 19 3. renice one of the nice 19 processes to nice 0 (you can also renice only n-1 processes in step 2 and omit this step) Actual Results: One CPU is idle, now. The n processes have to share the other n-1 CPUs. Expected Results: All CPUs should be busy. There are enough running processes. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c yang xiaoyu <xyyang@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |xyyang@novell.com AssignedTo|bnc-team-screening@forge.pr |kernel-maintainers@forge.pr |ovo.novell.com |ovo.novell.com -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c1 Jeff Mahoney <jeffm@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO CC| |jeffm@novell.com Info Provider| |b.willenberg@tu-bs.de --- Comment #1 from Jeff Mahoney <jeffm@novell.com> 2010-03-04 21:10:00 UTC --- Can you attach the output of lscpu for each system? Pasting it in a comment is fine. The output is pretty short. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c2 Björn Willenberg <b.willenberg@tu-bs.de> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW CC| |b.willenberg@tu-bs.de Info Provider|b.willenberg@tu-bs.de | --- Comment #2 from Björn Willenberg <b.willenberg@tu-bs.de> 2010-03-04 22:57:15 UTC --- (In reply to comment #1)
Can you attach the output of lscpu for each system?
1. system (n53), bug occurs # lscpu Architecture: x86_64 CPU(s): 8 Thread(s) per core: 1 Core(s) per socket: 4 CPU socket(s): 2 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 23 Stepping: 10 CPU MHz: 2000.065 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 6144K 2. system (n51), bug occurs openSUSE 10.2 (X86-64), does not seem to have lscpu in the util-linux package and it's too late to organize a working lscpu today. 3. system (carl), bug does not occur # lscpu Architecture: x86_64 CPU(s): 4 Thread(s) per core: 1 Core(s) per socket: 4 CPU socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 30 Stepping: 5 CPU MHz: 2793.000 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 8192K hope, this helps -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c3 --- Comment #3 from Björn Willenberg <b.willenberg@tu-bs.de> 2010-03-05 10:47:42 UTC --- (In reply to comment #2)
2. system (n51), bug occurs openSUSE 10.2 (X86-64), does not seem to have lscpu in the util-linux package and it's too late to organize a working lscpu today.
here is the output # ./lscpu Architecture: x86_64 CPU(s): 4 Thread(s) per core: 1 Core(s) per socket: 2 CPU socket(s): 2 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 15 Stepping: 6 CPU MHz: 1995.072 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 4096K -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c4 Jeff Mahoney <jeffm@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO Info Provider| |b.willenberg@tu-bs.de --- Comment #4 from Jeff Mahoney <jeffm@novell.com> 2010-03-05 14:32:15 UTC --- Are you able to reproduce this with the kernel from: http://download.opensuse.org/repositories/Kernel:/HEAD/openSUSE_11.1/ -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c5 Björn Willenberg <b.willenberg@tu-bs.de> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW Info Provider|b.willenberg@tu-bs.de | --- Comment #5 from Björn Willenberg <b.willenberg@tu-bs.de> 2010-03-08 08:35:28 UTC --- (In reply to comment #4)
Are you able to reproduce this with the kernel from:
http://download.opensuse.org/repositories/Kernel:/HEAD/openSUSE_11.1/
I'm not able to install the rpm on the second system due to dependencies, but it's not reproducible with the other two systems. It's working as I would expect. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c6 Jeff Mahoney <jeffm@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO Info Provider| |b.willenberg@tu-bs.de --- Comment #6 from Jeff Mahoney <jeffm@novell.com> 2010-03-08 20:14:53 UTC --- Ok, that's good news. Can you reproduce it with the kernel from: http://download.opensuse.org/repositories/Kernel:/openSUSE-11.2/openSUSE_11.... .. as well? -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=579901 http://bugzilla.novell.com/show_bug.cgi?id=579901#c7 Björn Willenberg <b.willenberg@tu-bs.de> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW Info Provider|b.willenberg@tu-bs.de | --- Comment #7 from Björn Willenberg <b.willenberg@tu-bs.de> 2010-03-09 09:52:18 UTC --- (In reply to comment #6)
Ok, that's good news. Can you reproduce it with the kernel from: http://download.opensuse.org/repositories/Kernel:/openSUSE-11.2/openSUSE_11....
Bug is reproducible. System 2 not tested. Bug occurs on system 1 and not on system 3. system 1: n53:~ # top top - 10:47:13 up 4 min, 2 users, load average: 7.33, 3.34, 1.29 Tasks: 167 total, 9 running, 158 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0%us, 0.0%sy,100.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu1 : 0.3%us, 0.0%sy, 99.7%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu2 : 0.3%us, 0.7%sy, 99.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu3 : 0.0%us, 0.0%sy,100.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu4 : 0.0%us, 0.0%sy,100.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu5 :100.0%us, 0.0%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu6 : 0.0%us, 0.0%sy,100.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu7 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 4054316k total, 287432k used, 3766884k free, 10376k buffers Swap: 4192924k total, 0k used, 4192924k free, 166284k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3791 singu 39 19 12160 2572 976 R 100 0.1 2:09.51 bc 3788 singu 20 0 12160 2568 976 R 100 0.1 2:27.00 bc 3782 singu 39 19 12160 2568 976 R 92 0.1 2:28.63 bc 3776 singu 39 19 12160 2568 976 R 89 0.1 2:28.95 bc 3794 singu 39 19 12160 2568 976 R 83 0.1 2:03.22 bc 3779 singu 39 19 12160 2568 976 R 83 0.1 2:29.15 bc 3785 singu 39 19 12160 2568 976 R 76 0.1 2:24.27 bc 3773 singu 39 19 12160 2568 976 R 75 0.1 2:40.40 bc n53:~ # uname -a Linux n53 2.6.31.12-18-default #1 SMP 2010-03-05 10:12:29 +0100 x86_64 x86_64 x86_64 GNU/Linux -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=579901 https://bugzilla.novell.com/show_bug.cgi?id=579901#c8 Jeff Mahoney <jeffm@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO InfoProvider| |b.willenberg@tu-bs.de --- Comment #8 from Jeff Mahoney <jeffm@novell.com> 2010-09-20 18:10:19 UTC --- Sorry to keep the ball rolling this way, but are you able to reproduce with openSUSE 11.3 or (better) openSUSE Factory? -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=579901 https://bugzilla.novell.com/show_bug.cgi?id=579901#c9 --- Comment #9 from Mike Galbraith <mgalbraith@novell.com> 2010-09-28 09:24:57 UTC --- I received some mail this morning that reminded me of this bnc (actually, I was looking for a different one, but found this, which looks like the same issue). A three patch series was posted to address imbalance when using SCHED_IDLE, but that shouldn't matter, weight is weight. I've built it in mainline, will see I can reproduce the problem in SLES11, and whether this cures it. http://lkml.org/lkml/2010/9/27/546 The conversation turn-around on this thread/issue has been kinda slow, but ongoing. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=579901 https://bugzilla.novell.com/show_bug.cgi?id=579901#c10 Jiri Slaby <jslaby@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |RESOLVED CC| |jslaby@novell.com InfoProvider|b.willenberg@tu-bs.de | Resolution| |WONTFIX --- Comment #10 from Jiri Slaby <jslaby@novell.com> 2011-03-02 21:13:40 UTC --- Ok, if you can reproduce with some later opensuse, reopen. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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