[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 2/5] trace-cmd: Use tracing directory to count C
From: |
Masami Hiramatsu |
Subject: |
Re: [Qemu-devel] [PATCH 2/5] trace-cmd: Use tracing directory to count CPUs |
Date: |
Thu, 23 Aug 2012 12:00:57 +0900 |
User-agent: |
Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 |
(2012/08/23 11:01), Masami Hiramatsu wrote:
> (2012/08/22 22:41), Steven Rostedt wrote:
>> On Wed, 2012-08-22 at 17:43 +0900, Yoshihiro YUNOMAE wrote:
>>> From: Masami Hiramatsu <address@hidden>
>>>
>>> Count debugfs/tracing/per_cpu/cpu* to determine the
>>> number of CPUs.
>>
>> I'm curious, do you find that sysconf doesn't return the # of CPUs the
>> system has?
>
> No, sysconf returns the number of hosts CPUs, not guests.
>
>> I've had boxes where the per_cpu/cpu* had more cpus than the
>> box actually holds. But this was a bug in the kernel, not the tool. This
>> change log needs to have rational instead of just explaining what the
>> patch does.
>
> Ah, I see. Hmm, then this should be enabled by a command line
> option or an environment variable.
Oops, I misunderstood. I'll add more comment for why this
should be tried instead of sysconf.
Thank you,
--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: address@hidden
[Qemu-devel] [PATCH 3/5] trace-cmd: Support trace-agent of virtio-trace, Yoshihiro YUNOMAE, 2012/08/22
[Qemu-devel] [PATCH 4/5] trace-cmd: Add non-blocking option for open() and splice_read(), Yoshihiro YUNOMAE, 2012/08/22
[Qemu-devel] [PATCH 5/5] trace-cmd: Use polling function, Yoshihiro YUNOMAE, 2012/08/22