On 04/21/2012 03:05 AM, Mathew, John wrote: > Hi, > > I had informed Chris about it, I guess he will be correcting it. > > Br > John Yes I am aware of the problem, and its on my task list to attend to. Sorry for the HEAD being in flux, we will stabilize very shortly.
Thanks Chris > >> -----Original Message----- >> From: Németh Márton [mailto:nm...@freemail.hu] >> Sent: Saturday, April 21, 2012 12:48 PM >> To: Powertop Mailing List; Mathew, John >> Subject: handle_trace_point() + cpu_idle: conditional jump depends on >> uninitialised value >> >> Hi, >> >> I run powertop [1] version 1dfdb80d6333960ed310fff7b60439f79d154a84 >> together with Valgrind. I get this message (among others): >> >> ==2739== Conditional jump or move depends on uninitialised value(s) >> ==2739== at 0x80689BB: >> perf_process_bundle::handle_trace_point(void*, int, unsigned long long) >> (do_process.cpp:552) >> ==2739== by 0x806391A: perf_bundle::process() (perf_bundle.cpp:303) >> ==2739== by 0x8069A53: process_process_data() (do_process.cpp:1101) >> ==2739== by 0x804FA4E: one_measurement(int) (main.cpp:174) >> ==2739== by 0x8050399: main (main.cpp:390) >> >> I checked the function perf_process_bundle::handle_trace_point() and it >> really >> looks like that the val variable is used uninitialized when event->name >> is "cpu_idle": >> >> void perf_process_bundle::handle_trace_point(void *trace, int cpu, >> uint64_t time) >> { >> // ... >> unsigned long long val; >> // ... >> >> else if (strcmp(event->name, "cpu_idle") == 0) { >> if (val == 4294967295) // ---> equals 0xFFFF_FFFF >> consume_blame(cpu); >> else >> set_wakeup_pending(cpu); >> } >> // ... >> } >> >> I have even found the commit introduced this fragment (using "git >> blame") >> but I'm not sure from where the value of the "val" variable should come >> from. >> >> commit ed91c3e55760cd5d906821d87377a087f9681016 >> Author: John Mathew<john.mat...@intel.com> >> Date: Wed Apr 18 16:50:32 2012 -0700 >> >> From kernel version 2.6.41 the power_start, power_end >> and power_frequency power traces will be replaced with >> cpu_idle and cpu_frequency power traces. Refer kernel >> documentation events-power.txt for details. This patch >> enables the use of new power traces and will fall back >> to old traces if new traces are not avaialable >> >> Patch rebased by hand to HEAD >> >> >> References: >> [1] powertop git repo >> git://github.com/fenrus75/powertop.git >> >> [2] Valgrind >> http://valgrind.org/ >> >> Regards, >> >> Márton Németh > --------------------------------------------------------------------- > Intel Finland Oy > Registered Address: PL 281, 00181 Helsinki > Business Identity Code: 0357606 - 4 > Domiciled in Helsinki > > This e-mail and any attachments may contain confidential material for > the sole use of the intended recipient(s). Any review or distribution > by others is strictly prohibited. If you are not the intended > recipient, please contact the sender and delete all copies. > > > _______________________________________________ > Power mailing list > Power@bughost.org > https://bughost.org/mailman/listinfo/power _______________________________________________ Power mailing list Power@bughost.org https://bughost.org/mailman/listinfo/power
