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SubjectRe: [PATCH] x86: avoid calling arch_trigger_all_cpu_backtrace() at the same time on SMP

* Dongdong Deng <dongdong.deng@windriver.com> wrote:

> +static int backtrace_flag;

> + if (cmpxchg(&backtrace_flag, 0, 1) != 0)

Sorry to be a PITA, but i asked for test_and_set() because that's the simplest
primitive. cmpxchg() semantics is not nearly as obvious and people regularly get it
wrong :-/

Also, variables that cmpxchg or test_and_set operates on need to be long, not int.

Ingo


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