On Mon, Mar 16, 2020 at 01:59:49PM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f967140dfb7442e2db0868b03b961f9c59418a1b Mon Sep 17 00:00:00 2001 From: Kim Phillips kim.phillips@amd.com Date: Wed, 11 Mar 2020 14:13:21 -0500 Subject: [PATCH] perf/amd/uncore: Replace manual sampling check with CAP_NO_INTERRUPT flag
Enable the sampling check in kernel/events/core.c::perf_event_open(), which returns the more appropriate -EOPNOTSUPP.
BEFORE:
$ sudo perf record -a -e instructions,l3_request_g1.caching_l3_cache_accesses true Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (l3_request_g1.caching_l3_cache_accesses). /bin/dmesg | grep -i perf may provide additional information.
With nothing relevant in dmesg.
AFTER:
$ sudo perf record -a -e instructions,l3_request_g1.caching_l3_cache_accesses true Error: l3_request_g1.caching_l3_cache_accesses: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
Fixes: c43ca5091a37 ("perf/x86/amd: Add support for AMD NB and L2I "uncore" counters") Signed-off-by: Kim Phillips kim.phillips@amd.com Signed-off-by: Borislav Petkov bp@suse.de Acked-by: Peter Zijlstra peterz@infradead.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200311191323.13124-1-kim.phillips@amd.com
I've worked around not having PERF_PMU_CAP_NO_EXCLUDE on older kernels and queued this patch for 4.19-4.4.