On Thu, Feb 20, 2014 at 10:10:46AM -0800, Greg KH wrote: > On Thu, Feb 20, 2014 at 06:56:24AM -0800, Dirk Brandewie wrote: > > On 02/19/2014 04:51 PM, Greg KH wrote: > > >On Wed, Feb 19, 2014 at 04:35:37PM -0800, Greg KH wrote: > > >>On Wed, Feb 19, 2014 at 04:03:40PM -0800, Dirk Brandewie wrote: > > >>>On 02/19/2014 02:47 PM, Greg KH wrote: > > >>>>Hi Dirk, > > >>>> > > >>>>I've been having some huge slowdowns on my box building kernels, and I > > >>>>took the time to bisect it down to commit > > >>>>fcb6a15c2e7e76d493e6f91ea889ab40e1c643a4 (intel_pstate: Take core C0 > > >>>>time into account for core busy calculation). With that patch reverted > > >>>>on Linus's current tree, my build speeds are back up to the normal rate. > > >>>> > > >>>>The difference is huge, 2 minutes to do a kernel build with that patch > > >>>>reverted, 8-10 minutes with it applied! With all of the stable kernel > > >>>>builds and other trees, this is a huge problem for my workload (all I do > > >>>>is kernel builds it seems...) > > >>>> > > >>>>I see some patches you marked as "fixes" that you sent to Rafael, do you > > >>>>want me to test any of those? How am I the only one seeing this > > >>>>problem, do you need my cpu information or anything else? > > >>> > > >>>Can you give me a description of you build system? CPU, number of > > >>>sockets, > > >> > > >>The last processor in /proc/cpuinfo: > > >> > > >>processor : 7 > > >>vendor_id : GenuineIntel > > >>cpu family : 6 > > >>model : 60 > > >>model name : Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz > > >>stepping : 3 > > >>microcode : 0x9 > > >>cpu MHz : 3556.464 > > >>cache size : 8192 KB > > >>physical id : 0 > > >>siblings : 8 > > >>core id : 3 > > >>cpu cores : 4 > > >>apicid : 7 > > >>initial apicid : 7 > > >>fpu : yes > > >>fpu_exception : yes > > >>cpuid level : 13 > > >>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 > > >>syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good > > >>nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 > > >>monitor ds_cpl vmx est tm2 ssse3 fma cx16 xtpr pdcm pcid sse4_1 sse4_2 > > >>movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm ida > > >>arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid > > >>fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid > > >>bogomips : 7000.78 > > >>clflush size : 64 > > >>cache_alignment : 64 > > >>address sizes : 39 bits physical, 48 bits virtual > > >> > > >>>building from/to local media. Any special setup I should use here for > > >>>my test? > > >> > > >>I build on a SSD-like disk (flash media on PCI Express slot), so I > > >>should have almost no i/o time. > > >> > > >>I build with 'make -j16' > > >> > > >>>If you have time having the output of turbostat for a build with and > > >>>without would be very useful. > > >> > > >> $ ./turbostat > > >> turbostat: no /dev/cpu/0/msr > > >> Try "# modprobe msr": No such file or directory > > >> > > >>Bah, I'll rebuild with msr and get you that info... > > > > > >Attached is two files, "fast_build.txt" is when your patch is reverted, > > >and building a kernel takes only 2 minutes. "slow_build.txt" is when > > >the patch is not reverted, using Linus's latest tree, and I stopped it > > >after a while because I got bored :) > > > > > >I think the numbers in these two files shows the real problem that is > > >happening... > > > > For some reason intel_pstate is deciding you have no load and no increasing > > the P state :-( > > > > > >If there's anything else you need me to test, please let me know. > > > > I are running on Linus's tree could you run the following script with the > > patch > > applied and send the output of "perf script". > > > > #! /bin/sh > > > > sudo perf record -C 5 -c 1 -e power:pstate_sample& > > sleep .5 > > foo=$! > > taskset -c 5 cat /dev/zero > /dev/null& > > bar=$! > > sleep 1 > > kill $bar > > sleep .5 > > sudo kill $foo > > The output of this is attached below as "bad.perf", and for comparison, > I ran this with the patch reverted, which is the result in the > "good.perf" file below. > > Anything else I can test?
Any progress on this? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
