Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH v12 2/5] perf: Add a counter for number of user access events in context | Date | Sat, 04 Dec 2021 15:23:39 +0100 |
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On Fri, Dec 03 2021 at 09:58, Rob Herring wrote: > On Tue, Nov 30, 2021 at 4:57 PM Thomas Gleixner <tglx@linutronix.de> wrote: > I've rewritten it like this: > > On arm64, user space counter access will be controlled differently > compared to x86. On x86, access in the strictest mode is enabled for all > tasks in an MM when any event is mmap'ed. For arm64, access is > explicitly requested for an event and only enabled when the event's > context is active. This avoids hooks into the arch context switch code > and gives better control of when access is enabled. > > In order to configure user space access when the PMU is enabled, it is > necessary to know if any event (currently active or not) in the current > context has user space accessed enabled. Add a counter similar to other > counters in the context to avoid walking the event list every time.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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