Thank you for your response. > On 03/03/2011 06:01 AM, Yasunori Goto wrote: > > > In this log, cpu4 and 6 repeat page faults. > > ---- > > handle_mm_fault jiffies64=4295160616 cpu=4 address=40019a38 pmdval=0000000070832067 ptehigh=00000000 ptelow=55171067 > > handle_mm_fault jiffies64=4295160616 cpu=6 address=40003a38 pmdval=0000000070832067 ptehigh=00000000 ptelow=551ef067 > > handle_mm_fault jiffies64=4295160616 cpu=6 address=40003a38 pmdval=0000000070832067 ptehigh=00000000 ptelow=551ef067 > > handle_mm_fault jiffies64=4295160616 cpu=4 address=40019a38 pmdval=0000000070832067 ptehigh=00000000 ptelow=55171067 > > handle_mm_fault jiffies64=4295160616 cpu=4 address=40019a38 pmdval=0000000070832067 ptehigh=00000000 ptelow=55171067 > > > I confirmed this phenomenon is reproduced on 2.6.31 and 2.6.38-rc5 > > of x86 kernel, and I heard this phenomenon doesn't occur on > > x86-64 kernel from another engineer who found this problem first. > > > > In addition, this phenomenon occurred on 4 boxes, so I think the cause > > is not hardware malfunction. > > On what CPU model(s) does this happen? I'll attach cpuinfo in my current box which can reproduce this problem. (1 socket, 4 cores, 8 logical cpus.) And summary of other 3 boxes are here. (Unfortunately, I can't use them now.) 1) Intel(R) Xeon(R) CPU X5680 @ 3.33GHz 2 socket, # of core -> 12 # of logical cpus -> 24 2) Intel(R) Xeon(R) CPU X7560 @ 2.27GHz 2 socket # of coer -> 8 # of logical cpus -> 16 3) Intel(R) Xeon(TM) CPU 3.80GHz 1 socket # of core 1 # of logical cpus -> 2 (The stop time was very short on 3rd box. It was about 5 seconds. But it was sometimes 1 hours on 1st box.) > > Obviously the PTE is present and allows read, write and > execute accesses, so the PTE should not cause any faults. > > That leaves the TLB. It looks almost like the CPU keeps > re-faulting on a (old?) TLB entry, possibly with wrong > permissions, and does not re-load it from the PTE. > > I know this "should not happen" on x86, but I cannot think > of an alternative explanation right now. Can you try flushing > the TLB entry in question from handle_pte_fault? I inserted __flush_tlb_one(address) between my debug print and calling handle_pte_fault(). But, this phenomenon is reproduced. > > It looks like the code already does this for write faults, but > maybe the garbage collection code uses PROT_NONE a lot and is > running into this issue with a read or exec fault? > > It would be good to print the fault flags as well in your debug > print, so we know what kind of fault is being repeated... I did it. The flags was 9 (FALUT_FLAG_ALLOW_RETRY and FAULT_FLAG_WRITE). ----- handle_mm_fault jiffies64=4295117679 cpu=7 address=40001788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54cb1067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=2 address=40007788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54d3b067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=6 address=40000000 pmdval=0000000070845067 ptehigh=00000000 ptelow=54cb0067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=4 address=40002788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54d22067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=7 address=40001788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54cb1067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=2 address=40007788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54d3b067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=6 address=40000000 pmdval=0000000070845067 ptehigh=00000000 ptelow=54cb0067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=4 address=40002788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54d22067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=7 address=40001788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54cb1067 flags=9 handle_mm_fault jiffies64=4295117679 cpu=2 address=40007788 pmdval=0000000070845067 ptehigh=00000000 ptelow=54d3b067 flags=9 ----- These outputs repeated many times.... Thanks. ----------- /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.20 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 1 cpu cores : 4 apicid : 2 initial apicid : 2 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.15 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 2 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 9 cpu cores : 4 apicid : 18 initial apicid : 18 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.15 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 10 cpu cores : 4 apicid : 20 initial apicid : 20 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.15 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 4 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 0 cpu cores : 4 apicid : 1 initial apicid : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.16 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 5 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 1 cpu cores : 4 apicid : 3 initial apicid : 3 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.15 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 6 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 9 cpu cores : 4 apicid : 19 initial apicid : 19 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.15 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 44 model name : Intel(R) Xeon(R) CPU E5640 @ 2.67GHz stepping : 1 cpu MHz : 1596.000 cache size : 12288 KB physical id : 0 siblings : 8 core id : 10 cpu cores : 4 apicid : 21 initial apicid : 21 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid bogomips : 5333.15 clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: -- Yasunori Goto -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . 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