[v1] perf: Clean ups and simplifications

[RESEND][PATCH 0/5] perf: Clean ups and simplifications

Posted by Steven Rostedt 1 month, 2 weeks ago

This is a resend from: https://lore.kernel.org/linux-trace-kernel/20250717173125.434618999@kernel.org/

It cleanly applied on top of the latest tip/perf/core:
  448f97fba901 ("perf: Convert mmap() refcounts to refcount_t")

The ongoing work to support sframes[1] in the kernel required a few clean ups
to the perf kernel side. Instead of having these changes in the ongoing
work, there's no reason they cannot be applied now.

These are just clean ups to the perf code to help simplify the updates that
will be made later.

[1] https://lore.kernel.org/linux-trace-kernel/20250708020003.565862284@kernel.org


Josh Poimboeuf (4):
      perf: Remove get_perf_callchain() init_nr argument
      perf: Have get_perf_callchain() return NULL if crosstask and user are set
      perf: Simplify get_perf_callchain() user logic
      perf: Skip user unwind if the task is a kernel thread

Steven Rostedt (1):
      perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL

----
 include/linux/perf_event.h |  2 +-
 kernel/bpf/stackmap.c      |  4 ++--
 kernel/events/callchain.c  | 40 +++++++++++++++++++---------------------
 kernel/events/core.c       |  9 +++++----
 4 files changed, 27 insertions(+), 28 deletions(-)

Re: [RESEND][PATCH 0/5] perf: Clean ups and simplifications

Posted by Peter Zijlstra 1 month, 1 week ago

On Wed, Aug 20, 2025 at 02:03:38PM -0400, Steven Rostedt wrote:
> 
> This is a resend from: https://lore.kernel.org/linux-trace-kernel/20250717173125.434618999@kernel.org/
> 
> It cleanly applied on top of the latest tip/perf/core:
>   448f97fba901 ("perf: Convert mmap() refcounts to refcount_t")
> 
> The ongoing work to support sframes[1] in the kernel required a few clean ups
> to the perf kernel side. Instead of having these changes in the ongoing
> work, there's no reason they cannot be applied now.
> 
> These are just clean ups to the perf code to help simplify the updates that
> will be made later.
> 
> [1] https://lore.kernel.org/linux-trace-kernel/20250708020003.565862284@kernel.org
> 
> 
> Josh Poimboeuf (4):
>       perf: Remove get_perf_callchain() init_nr argument
>       perf: Have get_perf_callchain() return NULL if crosstask and user are set
>       perf: Simplify get_perf_callchain() user logic
>       perf: Skip user unwind if the task is a kernel thread
> 
> Steven Rostedt (1):
>       perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL

Thanks!