Re: [PATCH v10 07/14] unwind_user/deferred: Make unwind deferral requests NMI-safe
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-06-19 09:10:26
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On June 19, 2025 4:48:13 AM EDT, Peter Zijlstra [off-list ref] wrote:
On Thu, Jun 19, 2025 at 10:44:27AM +0200, Peter Zijlstra wrote:quoted
Luckily, x86 dropped support for !CMPXCHG8B right along with !TSC. So on x86 we good with timestamps, even on 32bit.Well, not entirely true, local_clock() is not guaranteed monotonic. So you might be in for quite a bit of hurt if you rely on that.
As long as it is monotonic per task. If it is not, then pretty much all tracers that use it are broken. -- Steve