perf kvm: Simplify exit reasons tables definitions

The perf_kvm_stat struct keeps the size of a table of exit reasons in
the field 'exit_reasons_size'.

The field is initialized and then used by get_exit_reason() for serial
access to the table, so that the calling function does not actually need
to know table size.

Usage of tables with 'end of sequence' marker simplifies the
get_exit_reason() function.

Also the patch introduces a define_exit_reasons_table, which makes it
easier to define new tables.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1404395992-17095-3-git-send-email-yarygin@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 214ec0e..75f3544 100644 (file)
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -99,7 +99,6 @@ struct perf_kvm_stat {
        int trace_vcpu;
 
        struct exit_reasons_table *exit_reasons;
-       int exit_reasons_size;
        const char *exit_reasons_isa;
 
        struct kvm_events_ops *events_ops;
@@ -158,20 +157,19 @@ static bool exit_event_end(struct perf_evsel *evsel,
        return kvm_entry_event(evsel);
 }
 
-static struct exit_reasons_table vmx_exit_reasons[] = {
-       VMX_EXIT_REASONS
-};
+#define define_exit_reasons_table(name, symbols)       \
+       static struct exit_reasons_table name[] = {     \
+               symbols, { -1, NULL }                   \
+       }
 
-static struct exit_reasons_table svm_exit_reasons[] = {
-       SVM_EXIT_REASONS
-};
+define_exit_reasons_table(vmx_exit_reasons, VMX_EXIT_REASONS);
+define_exit_reasons_table(svm_exit_reasons, SVM_EXIT_REASONS);
 
-static const char *get_exit_reason(struct perf_kvm_stat *kvm, u64 exit_code)
+static const char *get_exit_reason(struct perf_kvm_stat *kvm,
+                                  struct exit_reasons_table *tbl,
+                                  u64 exit_code)
 {
-       int i = kvm->exit_reasons_size;
-       struct exit_reasons_table *tbl = kvm->exit_reasons;
-
-       while (i--) {
+       while (tbl->reason != NULL) {
                if (tbl->exit_code == exit_code)
                        return tbl->reason;
                tbl++;
@@ -186,7 +184,8 @@ static void exit_event_decode_key(struct perf_kvm_stat *kvm,
                                  struct event_key *key,
                                  char decode[20])
 {
-       const char *exit_reason = get_exit_reason(kvm, key->key);
+       const char *exit_reason = get_exit_reason(kvm, kvm->exit_reasons,
+                                                 key->key);
 
        scnprintf(decode, 20, "%s", exit_reason);
 }
@@ -862,7 +861,6 @@ static int cpu_isa_config(struct perf_kvm_stat *kvm)
 
        if (isa == 1) {
                kvm->exit_reasons = vmx_exit_reasons;
-               kvm->exit_reasons_size = ARRAY_SIZE(vmx_exit_reasons);
                kvm->exit_reasons_isa = "VMX";
        }
 
@@ -1586,7 +1584,6 @@ static int kvm_cmd_stat(const char *file_name, int argc, const char **argv)
                .sort_key       = "sample",
 
                .exit_reasons = svm_exit_reasons,
-               .exit_reasons_size = ARRAY_SIZE(svm_exit_reasons),
                .exit_reasons_isa = "SVM",
        };