On 2014/10/15 23:13, Arnaldo Carvalho de Melo wrote: > Em Wed, Oct 15, 2014 at 11:28:53AM +0800, Wang Nan escreveu: >> Commit fbe96f29 (perf tools: Make perf.data more self-descriptive) >> read '/proc/cpuinfo' to form cpu descriptor. For ARM, it finds >> 'Processor' field. It is correct when the patch merged, but due to >> commit b4b8f770 (ARM: kernel: update cpuinfo to print all online CPUs >> features), the corresponding information becomes 'model name' field. >> >> This patch simply corrects it. > > It doesn't :-) > > It makes it work with kernels >= b4b8f770, and fail with older kernels. > > We need to somehow figure out where the right information is regardless > of the kernel. > > - Arnaldo >
However it is a real problem. Look at output on arm platform at the bottom of this mail, especially "cpudesc", "total memory" and "cmdline" field. By further debugging I found that the real problem resides in return value checking when write header error. Please see my other patches: https://lkml.org/lkml/2014/10/15/612 https://lkml.org/lkml/2014/10/15/611 I think at least one of them is required. Thanks. >> Signed-off-by: Wang Nan <wangn...@huawei.com> >> --- >> tools/perf/perf-sys.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/perf/perf-sys.h b/tools/perf/perf-sys.h >> index 937e432..4293970 100644 >> --- a/tools/perf/perf-sys.h >> +++ b/tools/perf/perf-sys.h >> @@ -113,7 +113,7 @@ >> #define mb() ((void(*)(void))0xffff0fa0)() >> #define wmb() ((void(*)(void))0xffff0fa0)() >> #define rmb() ((void(*)(void))0xffff0fa0)() >> -#define CPUINFO_PROC "Processor" >> +#define CPUINFO_PROC "model name" >> #endif >> >> #ifdef __aarch64__ >> -- >> 1.8.4 bash-4.2# perf record ls ... [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.001 MB perf.data (~36 samples) ] bash-4.2# perf report --stdio --header Error: The perf.data file has no samples! # ======== # captured on: Fri Sep 12 10:09:10 2014 # hostname : arma15el # os release : 3.17.0+ # perf version : 3.10.53 # arch : armv7l # nrcpus online : 4 # nrcpus avail : 1 # cpudesc : (null) # total memory : 0 kB # cmdline : # event : name = cycles, type = 0, config = 0x0, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_kern = 0, excl_host = 0, excl_guest = 1, precise_ip = 0 # pmu mappings: not available # ======== # -- 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/
