perf kvm: Reference count 'struct kvm_info'

hists__add_entry_ops() doesn't allocate a new histogram entry if it has
an existing entry for a KVM event, in this case, find_create_kvm_event()
allocates a 'struct kvm_info' but it's not used by any histograms and
never freed.

To fix the memory leak, this patch first introduces a refcnt and a set
of functions for refcnt operations on 'struct kvm_info'.  When the data
structure is not anymore used (the refcnt hits zero) kvm_info__zput()
will free the memory used.

Committer:

Provide a nop version of kvm_info__zput() to be used when
HAVE_KVM_STAT_SUPPORT isn't defined as it is used unconditionally in
hists__findnew_entry() and hist_entry__delete().

Signed-off-by: Leo Yan <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions