Re: [PATCH v13 0/5] arm64 userspace counter support

Will Deacon
2021-12-14T14:06:43Z

On Wed, 8 Dec 2021 14:11:19 -0600, Rob Herring wrote:
> Another version of arm64 userspace counter access support. No changes from
> the last version except rebasing and rewriting a commit message.
>
> The arm64 support departs from the x86 implementation by requiring the user
> to explicitly request user access (via attr.config1) and only enables access
> for task bound events. Since usage is explicitly requested, access is
> enabled at perf_event_open() rather than on mmap() as that greatly
> simplifies the implementation. Rather than trying to lock down the access
> as the x86 implementation has been doing, we can start with only a limited
> use case enabled and later expand it if needed.
>
> [...]

Applied to will (for-next/perf-user-counter-access), thanks!

[1/5] x86: perf: Move RDPMC event flag to a common definition
https://git.kernel.org/arm64/c/369461ce8fb6
[2/5] perf: Add a counter for number of user access events in context
https://git.kernel.org/arm64/c/82ff0c022d19
[3/5] arm64: perf: Add userspace counter access disable switch
https://git.kernel.org/arm64/c/e2012600810c
[4/5] arm64: perf: Enable PMU counter userspace access for perf event
https://git.kernel.org/arm64/c/83a7a4d643d3
[5/5] Documentation: arm64: Document PMU counters access from userspace
https://git.kernel.org/arm64/c/aa1005d15d2a

Cheers,
--
Will