From: Andy Lutomirski <luto@kernel.org>
To: Qi Zheng <zhengqi.arch@bytedance.com>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
hpa@zytor.com, peterz@infradead.org, x86@kernel.org
Cc: linux-kernel@vger.kernel.org, songmuchun@bytedance.com
Subject: Re: [PATCH] x86: fix get_wchan() not support the ORC unwinder
Date: Mon, 14 Jun 2021 09:21:12 -0700 [thread overview]
Message-ID: <06292162-5a44-6f91-140d-e1211c006ad0@kernel.org> (raw)
In-Reply-To: <20210611124642.72910-1-zhengqi.arch@bytedance.com>
On 6/11/21 5:46 AM, Qi Zheng wrote:
> Currently, the kernel CONFIG_UNWINDER_ORC option is enabled by
> default on x86, but the implementation of get_wchan() is still
> based on the frame pointer unwinder, so the /proc/<pid>/wchan
> always return 0 regardless of whether the task <pid> is running.
>
> We reimplement the get_wchan() by calling stack_trace_save_tsk(),
> which is adapted to the ORC and frame pointer unwinders.
How much slower does this make ps?
--Andy
next prev parent reply other threads:[~2021-06-14 16:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-11 12:46 [PATCH] x86: fix get_wchan() not support the ORC unwinder Qi Zheng
2021-06-14 16:21 ` Andy Lutomirski [this message]
2021-06-16 7:34 ` [External] " 郑琦
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