This is a note to let you know that I've just added the patch titled perf iostat: Use system-wide mode if the target cpu_list is unspecified to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-iostat-use-system-wide-mode-if-the-target-cpu_l.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f21ba66b4f36a3e6eb6b7a2756d096048684a1ba Author: Like Xu <likexu@xxxxxxxxxxx> Date: Mon Sep 27 16:11:14 2021 +0800 perf iostat: Use system-wide mode if the target cpu_list is unspecified [ Upstream commit e4fe5d7349e0b1c0d3da5b6b3e1efce591e85bd2 ] An iostate use case like "perf iostat 0000:16,0000:97 -- ls" should be implemented to work in system-wide mode to ensure that the output from print_header() is consistent with the user documentation perf-iostat.txt, rather than incorrectly assuming that the kernel does not support it: Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) \ for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/). /bin/dmesg | grep -i perf may provide additional information. This error is easily fixed by assigning system-wide mode by default for IOSTAT_RUN only when the target cpu_list is unspecified. Fixes: f07952b179697771 ("perf stat: Basic support for iostat in perf") Signed-off-by: Like Xu <likexu@xxxxxxxxxxx> Cc: Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Ian Rogers <irogers@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Link: http://lore.kernel.org/lkml/20210927081115.39568-1-likexu@xxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 634375937db9..36033a7372f9 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -2406,6 +2406,8 @@ int cmd_stat(int argc, const char **argv) goto out; } else if (verbose) iostat_list(evsel_list, &stat_config); + if (iostat_mode == IOSTAT_RUN && !target__has_cpu(&target)) + target.system_wide = true; } if (add_default_attributes())