From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: akpm@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org,
keescook@chromium.org, lauraa@codeaurora.org,
viresh.kumar@linaro.org, nicolas.pitre@linaro.org,
thomas.lendacky@amd.com
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: A question of sleeping with interrupts are disabled in start_kernel()
Date: Fri, 6 Apr 2018 17:53:21 +0800 [thread overview]
Message-ID: <1eb16c24-ef3b-2962-d216-57f66321035e@gmail.com> (raw)
Hello,
I have a question of the call path init/main.c:
init/main.c: start_kernel() ->
kernel/events/core.c: perf_pmu_register() ->
kernel/events/core.c: perf_event_init() ->
kernel/events/core.c: pmu_dev_alloc()
In this call path, start_kernel() calls local_irq_disable() to disable
the interrupt;
perf_pmu_register() calls mutex_lock() and idr_alloc(GFP_KERNEL), and
they can sleep;
pmu_dev_alloc() calls kzalloc(GFP_KERNEL), and it can sleep.
In my opinion, this code may sleep with interrupts are disabled.
I wonder why this code is okay?
Best wishes,
Jia-Ju Bai
next reply other threads:[~2018-04-06 9:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-06 9:53 Jia-Ju Bai [this message]
2018-04-06 10:27 ` Thomas Gleixner
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