linux/tools
Ian Rogers 94dbfd6781 perf parse-events: Architecture specific leader override
Currently topdown events must appear after a slots event:

  $ perf stat -e '{slots,topdown-fe-bound}' /bin/true

   Performance counter stats for '/bin/true':

         3,183,090      slots
           986,133      topdown-fe-bound

Reversing the events yields:

  $ perf stat -e '{topdown-fe-bound,slots}' /bin/true
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (topdown-fe-bound).

For metrics the order of events is determined by iterating over a
hashmap, and so slots isn't guaranteed to be first which can yield this
error.

Change the set_leader in parse-events, called when a group is closed, so
that rather than always making the first event the leader, if the slots
event exists then it is made the leader. It is then moved to the head of
the evlist otherwise it won't be opened in the correct order.

The result is:

  $ perf stat -e '{topdown-fe-bound,slots}' /bin/true

   Performance counter stats for '/bin/true':

         3,274,795      slots
         1,001,702      topdown-fe-bound

A problem with this approach is the slots event is identified by name,
names can be overwritten like 'cpu/slots,name=foo/' and this causes the
leader change to fail.

The change also modifies and fixes mixed groups like, with the change:

  $ perf stat -e '{instructions,slots,topdown-fe-bound}' -a -- sleep 2

   Performance counter stats for 'system wide':

        5574985410      slots
         971981616      instructions
        1348461887      topdown-fe-bound

       2.001263120 seconds time elapsed

Without the change:

  $ perf stat -e '{instructions,slots,topdown-fe-bound}' -a -- sleep 2

   Performance counter stats for 'system wide':

     <not counted>      instructions
     <not counted>      slots
   <not supported>      topdown-fe-bound

       2.006247990 seconds time elapsed

Something that may be undesirable here is that the events are reordered
in the output.

Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vineet Singh <vineet.singh@intel.com>
Link: http://lore.kernel.org/lkml/20211130174945.247604-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-07 22:18:24 -03:00
..
accounting
arch tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources 2021-11-18 10:08:07 -03:00
bootconfig bootconfig: Cleanup dummy headers in tools/bootconfig 2021-10-10 22:16:02 -04:00
bpf tools/runqslower: Fix cross-build 2021-11-12 17:23:16 -08:00
build tools build: Enable warnings through HOSTCFLAGS 2021-12-07 22:18:23 -03:00
cgroup
counter tools/counter: Create Counter tools 2021-10-17 10:54:16 +01:00
debugging
edid
firewire
firmware
gpio
hv
iio
include tools: Fix math.h breakage 2021-11-30 09:14:42 -08:00
io_uring tools/io_uring/io_uring-cp: sync with liburing example 2021-08-13 08:58:11 -06:00
kvm/kvm_stat KVM: kvm_stat: do not show halt_wait_ns 2021-10-18 14:07:18 -04:00
laptop
leds
lib perf evlist: Allow setting arbitrary leader 2021-12-07 22:18:24 -03:00
memory-model tools/memory-model: Document data_race(READ_ONCE()) 2021-07-27 11:48:55 -07:00
objtool objtool: Fix pv_ops noinstr validation 2021-12-03 09:11:42 +01:00
pci tools: PCI: Zero-initialize param 2021-08-05 11:01:30 +01:00
pcmcia
perf perf parse-events: Architecture specific leader override 2021-12-07 22:18:24 -03:00
power
rcu tools/rcu: Add an extract-stall script 2021-09-16 10:31:26 -07:00
scripts tools, build: Add RISC-V to HOSTARCH parsing 2021-11-01 17:08:21 +01:00
spi
testing Networking fixes for 5.16-rc4, including fixes from wireless, 2021-12-02 11:22:06 -08:00
thermal/tmon tools/thermal/tmon: Add cross compiling support 2021-08-14 15:33:19 +02:00
time
tracing tools/latency-collector: Use correct size when writing queue_full_warning 2021-10-25 22:27:19 -04:00
usb usb: testusb: Fix for showing the connection speed 2021-09-14 10:31:41 +02:00
virtio tools/virtio: fix build 2021-08-11 06:44:24 -04:00
vm tools/vm/page-types.c: print file offset in hexadecimal 2021-11-06 13:30:40 -07:00
wmi
Makefile tools/lib/lockdep: drop liblockdep 2021-11-12 11:07:17 -08:00