perf header: Fix false warning when there are no duplicate cache entries
Before this patch, perf expected that there might be NPROC*4 unique
cache entries at max, however, it also expected that some of them would
be shared and/or of the same size, thus the final number of entries
would be reduced to be lower than NPROC*4. In case the number of entries
hadn't been reduced (was NPROC*4), the warning was printed.
However, some systems might have unusual cache topology, such as the
following two-processor KVM guest:
cpu level shared_cpu_list size
0 1 0 32K
0 1 0 64K
0 2 0 512K
0 3 0 8192K
1 1 1 32K
1 1 1 64K
1 2 1 512K
1 3 1 8192K
This KVM guest has 8 (NPROC*4) unique cache entries, which used to make
perf printing the message, although there actually aren't "way too many
cpu caches".
v2: Removing unused argument.
v3: Unifying the way we obtain number of cpus.
v4: Removed '& UINT_MAX' construct which is redundant.
Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
LPU-Reference: 20191208162056.20772-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 file changed
