Messages in this thread |  | | | Date | Tue, 25 May 2010 20:15:45 +0200 | | From | Piotr Hosowicz <> | | Subject | Re: BUG: using smp_processor_id() in preemptible [00000000] code: icedove-bin/5449 |
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On 25.05.2010 20:07, Divyesh Shah wrote: > On Tue, May 25, 2010 at 1:50 AM, Peter Zijlstra<peterz@infradead.org> wrote: >> On Mon, 2010-05-24 at 05:03 +0200, Piotr Hosowicz wrote: >>> [ 720.313607] BUG: using smp_processor_id() in preemptible [00000000] code: icedove-bin/5449 >>> [ 720.313612] caller is native_sched_clock+0x3c/0x68 >>> [ 720.313616] Pid: 5449, comm: icedove-bin Tainted: P 2.6.34-20100524-0407 #1 >>> [ 720.313618] Call Trace: >>> [ 720.313624] [<ffffffff811a533b>] debug_smp_processor_id+0xc7/0xe0 >>> [ 720.313629] [<ffffffff81009b87>] native_sched_clock+0x3c/0x68 >>> [ 720.313634] [<ffffffff81009a4d>] sched_clock+0x9/0xd >>> [ 720.313637] [<ffffffff811823ec>] blk_rq_init+0x92/0x9d >>> [ 720.313641] [<ffffffff81184227>] get_request+0x1bf/0x2c7 >>> [ 720.313646] [<ffffffff8118435c>] get_request_wait+0x2d/0x19d >> >> This comes from wreckage in the blk tree.. >> >> --- >> commit 9195291e5f05e01d67f9a09c756b8aca8f009089 >> Author: Divyesh Shah<dpshah@google.com> >> Date: Thu Apr 1 15:01:41 2010 -0700 >> >> blkio: Increment the blkio cgroup stats for real now >> >> We also add start_time_ns and io_start_time_ns fields to struct request >> here to record the time when a request is created and when it is >> dispatched to device. We use ns uints here as ms and jiffies are >> not very useful for non-rotational media. >> >> Signed-off-by: Divyesh Shah<dpshah@google.com> >> Signed-off-by: Jens Axboe<jens.axboe@oracle.com> >> --- >> >> +#ifdef CONFIG_BLK_CGROUP >> +static inline void set_start_time_ns(struct request *req) >> +{ >> + req->start_time_ns = sched_clock(); >> +} >> + >> +static inline void set_io_start_time_ns(struct request *req) >> +{ >> + req->io_start_time_ns = sched_clock(); >> +} >> +#else >> +static inline void set_start_time_ns(struct request *req) {} >> +static inline void set_io_start_time_ns(struct request *req) {} >> +#endif >> >> --- >> >> Clearly nobody tested this, and its terribly broken to boot. > > @Piotr, do you have kernel pre-emption enabled?
Yes.
Regards,
Piotr Hosowicz
-- Janusz Korwin-Mikke: "Dyktatury dzielą się na dobre i złe. Demokracja jest zawsze głupia." NP: - NB: 2.6.34-20100525-1754-patched -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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