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5debf02131
The commit3966c3feca("x86/perf/amd: Remove need to check "running" bit in NMI handler") introduced this. It seems x86_pmu_stop can be called recursively (like when it losts some samples) like below: x86_pmu_stop intel_pmu_disable_event (x86_pmu_disable) intel_pmu_pebs_disable intel_pmu_drain_pebs_nhm (x86_pmu_drain_pebs_buffer) x86_pmu_stop While commit35d1ce6bec("perf/x86/intel/ds: Fix x86_pmu_stop warning for large PEBS") fixed it for the normal cases, there's another path to call x86_pmu_stop() recursively when a PEBS error was detected (like two or more counters overflowed at the same time). Like in the Kan's previous fix, we can skip the interrupt accounting for large PEBS, so check the iregs which is set for PMI only. Fixes:3966c3feca("x86/perf/amd: Remove need to check "running" bit in NMI handler") Reported-by: John Sperbeck <jsperbeck@google.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201126110922.317681-1-namhyung@kernel.org
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.