perf/x86/intel: Reduce lbr_sel_map[] size

The index of lbr_sel_map is bit value of perf branch_sample_type.
PERF_SAMPLE_BRANCH_MAX is 1024 at present, so each lbr_sel_map uses
4096 bytes. By using bit shift as index, we can reduce lbr_sel_map
size to 40 bytes. This patch defines 'bit shift' for branch types,
and use 'bit shift' to define lbr_sel_maps.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: jolsa@redhat.com
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/1415156173-10035-2-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 29 insertions, 29 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index df525d2be1e8..0c45b22495dc 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -515,6 +515,10 @@ struct x86_pmu {
         struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr);
 };
 
+enum {
+        PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE = PERF_SAMPLE_BRANCH_MAX_SHIFT,
+};
+
 #define x86_add_quirk(func_)                                            \
 do {                                                                    \
         static struct x86_pmu_quirk __quirk __initdata = {              \
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 58f1a94beaf0..8bc078f43a82 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -69,10 +69,6 @@ static enum {
 #define LBR_FROM_FLAG_IN_TX    (1ULL << 62)
 #define LBR_FROM_FLAG_ABORT    (1ULL << 61)
 
-#define for_each_branch_sample_type(x) \
-        for ((x) = PERF_SAMPLE_BRANCH_USER; \
-             (x) < PERF_SAMPLE_BRANCH_MAX; (x) <<= 1)
-
 /*
  * x86control flow change classification
  * x86control flow changes include branches, interrupts, traps, faults
@@ -403,14 +399,14 @@ static int intel_pmu_setup_hw_lbr_filter(struct perf_event *event)
 {
         struct hw_perf_event_extra *reg;
         u64 br_type = event->attr.branch_sample_type;
-        u64 mask = 0, m;
-        u64 v;
+        u64 mask = 0, v;
+        int i;
 
-        for_each_branch_sample_type(m) {
-                if (!(br_type & m))
+        for (i = 0; i < PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE; i++) {
+                if (!(br_type & (1ULL << i)))
                         continue;
 
-                v = x86_pmu.lbr_sel_map[m];
+                v = x86_pmu.lbr_sel_map[i];
                 if (v == LBR_NOT_SUPP)
                         return -EOPNOTSUPP;
 
@@ -678,35 +674,35 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
 /*
  * Map interface branch filters onto LBR filters
  */
-static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
-        [PERF_SAMPLE_BRANCH_ANY]        = LBR_ANY,
-        [PERF_SAMPLE_BRANCH_USER]       = LBR_USER,
-        [PERF_SAMPLE_BRANCH_KERNEL]     = LBR_KERNEL,
-        [PERF_SAMPLE_BRANCH_HV]         = LBR_IGN,
-        [PERF_SAMPLE_BRANCH_ANY_RETURN] = LBR_RETURN | LBR_REL_JMP
-                                        | LBR_IND_JMP | LBR_FAR,
+static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE] = {
+        [PERF_SAMPLE_BRANCH_ANY_SHIFT]          = LBR_ANY,
+        [PERF_SAMPLE_BRANCH_USER_SHIFT]         = LBR_USER,
+        [PERF_SAMPLE_BRANCH_KERNEL_SHIFT]       = LBR_KERNEL,
+        [PERF_SAMPLE_BRANCH_HV_SHIFT]           = LBR_IGN,
+        [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]   = LBR_RETURN | LBR_REL_JMP
+                                                | LBR_IND_JMP | LBR_FAR,
         /*
          * NHM/WSM erratum: must include REL_JMP+IND_JMP to get CALL branches
          */
-        [PERF_SAMPLE_BRANCH_ANY_CALL] =
+        [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] =
          LBR_REL_CALL | LBR_IND_CALL | LBR_REL_JMP | LBR_IND_JMP | LBR_FAR,
         /*
          * NHM/WSM erratum: must include IND_JMP to capture IND_CALL
          */
-        [PERF_SAMPLE_BRANCH_IND_CALL] = LBR_IND_CALL | LBR_IND_JMP,
-        [PERF_SAMPLE_BRANCH_COND]     = LBR_JCC,
+        [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL | LBR_IND_JMP,
+        [PERF_SAMPLE_BRANCH_COND_SHIFT]     = LBR_JCC,
 };
 
-static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
-        [PERF_SAMPLE_BRANCH_ANY]        = LBR_ANY,
-        [PERF_SAMPLE_BRANCH_USER]       = LBR_USER,
-        [PERF_SAMPLE_BRANCH_KERNEL]     = LBR_KERNEL,
-        [PERF_SAMPLE_BRANCH_HV]         = LBR_IGN,
-        [PERF_SAMPLE_BRANCH_ANY_RETURN] = LBR_RETURN | LBR_FAR,
-        [PERF_SAMPLE_BRANCH_ANY_CALL]   = LBR_REL_CALL | LBR_IND_CALL
-                                        | LBR_FAR,
-        [PERF_SAMPLE_BRANCH_IND_CALL]   = LBR_IND_CALL,
-        [PERF_SAMPLE_BRANCH_COND]       = LBR_JCC,
+static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE] = {
+        [PERF_SAMPLE_BRANCH_ANY_SHIFT]          = LBR_ANY,
+        [PERF_SAMPLE_BRANCH_USER_SHIFT]         = LBR_USER,
+        [PERF_SAMPLE_BRANCH_KERNEL_SHIFT]       = LBR_KERNEL,
+        [PERF_SAMPLE_BRANCH_HV_SHIFT]           = LBR_IGN,
+        [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]   = LBR_RETURN | LBR_FAR,
+        [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]     = LBR_REL_CALL | LBR_IND_CALL
+                                                | LBR_FAR,
+        [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]     = LBR_IND_CALL,
+        [PERF_SAMPLE_BRANCH_COND_SHIFT]         = LBR_JCC,
 };
 
 /* core */