From: Jian Yu <jian.yu@oracle.com>
Date: Mon, 8 Nov 2010 10:09:36 +0000 (+0800)
Subject: b=23289 lprocfs_counter cleanup
X-Git-Tag: 2.0.56.0~30
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=1cb2b41a12176f30b0a36be75bec0e1253d8f3ef

b=23289 lprocfs_counter cleanup

Eliminate unnecessary atomic operations in lprocfs_counter.

o=liang
i=andreas.dilger
i=maxim.patlasov
---

diff --git a/lustre/include/lprocfs_status.h b/lustre/include/lprocfs_status.h
index c7b077c..bebcbf5 100644
--- a/lustre/include/lprocfs_status.h
+++ b/lustre/include/lprocfs_status.h
@@ -169,8 +169,6 @@ enum lprocfs_stats_flags {
         LPROCFS_STATS_FLAG_NONE     = 0x0000, /* per cpu counter */
         LPROCFS_STATS_FLAG_NOPERCPU = 0x0001, /* stats have no percpu
                                                * area and need locking */
-        LPROCFS_STATS_GET_SMP_ID    = 0x0002, /* just record locking with
-                                               * LPROCFS_GET_SMP_ID flag */
 };
 
 enum lprocfs_fields_flags {
@@ -347,33 +345,48 @@ static inline void s2dhms(struct dhms *ts, time_t secs)
 
 #ifdef LPROCFS
 
-static inline int lprocfs_stats_lock(struct lprocfs_stats *stats, int type)
+static inline int lprocfs_stats_lock(struct lprocfs_stats *stats, int opc)
 {
-        int rc = 0;
-
-        if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU) {
-                if (type & LPROCFS_GET_NUM_CPU)
-                        rc = 1;
-                if (type & LPROCFS_GET_SMP_ID)
-                        rc = 0;
-                cfs_spin_lock(&stats->ls_lock);
-        } else {
-                if (type & LPROCFS_GET_NUM_CPU)
-                        rc = cfs_num_possible_cpus();
-                if (type & LPROCFS_GET_SMP_ID) {
-                        stats->ls_flags |= LPROCFS_STATS_GET_SMP_ID;
-                        rc = cfs_get_cpu();
+        switch (opc) {
+        default:
+                LBUG();
+
+        case LPROCFS_GET_SMP_ID:
+                if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU) {
+                        cfs_spin_lock(&stats->ls_lock);
+                        return 0;
+                } else {
+                        return cfs_get_cpu();
+                }
+
+        case LPROCFS_GET_NUM_CPU:
+                if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU) {
+                        cfs_spin_lock(&stats->ls_lock);
+                        return 1;
+                } else {
+                        return cfs_num_possible_cpus();
                 }
         }
-        return rc;
 }
 
-static inline void lprocfs_stats_unlock(struct lprocfs_stats *stats)
+static inline void lprocfs_stats_unlock(struct lprocfs_stats *stats, int opc)
 {
-        if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU)
-                cfs_spin_unlock(&stats->ls_lock);
-        else if (stats->ls_flags & LPROCFS_STATS_GET_SMP_ID)
-                cfs_put_cpu();
+        switch (opc) {
+        default:
+                LBUG();
+
+        case LPROCFS_GET_SMP_ID:
+                if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU)
+                        cfs_spin_unlock(&stats->ls_lock);
+                else
+                        cfs_put_cpu();
+                return;
+
+        case LPROCFS_GET_NUM_CPU:
+                if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU)
+                        cfs_spin_unlock(&stats->ls_lock);
+                return;
+        }
 }
 
 /* Two optimized LPROCFS counter increment functions are provided:
@@ -724,6 +737,8 @@ static inline void lprocfs_counter_add(struct lprocfs_stats *stats,
                                        int index, long amount) { return; }
 static inline void lprocfs_counter_incr(struct lprocfs_stats *stats,
                                         int index) { return; }
+static inline void lprocfs_counter_decr(struct lprocfs_stats *stats,
+                                        int index) { return; }
 static inline void lprocfs_counter_sub(struct lprocfs_stats *stats,
                                        int index, long amount) { return; }
 static inline void lprocfs_counter_init(struct lprocfs_stats *stats,
diff --git a/lustre/lvfs/lvfs_lib.c b/lustre/lvfs/lvfs_lib.c
index 9ec5e6f..7bfe92d 100644
--- a/lustre/lvfs/lvfs_lib.c
+++ b/lustre/lvfs/lvfs_lib.c
@@ -172,7 +172,8 @@ void lprocfs_counter_add(struct lprocfs_stats *stats, int idx,
         smp_id = lprocfs_stats_lock(stats, LPROCFS_GET_SMP_ID);
 
         percpu_cntr = &(stats->ls_percpu[smp_id]->lp_cntr[idx]);
-        cfs_atomic_inc(&percpu_cntr->lc_cntl.la_entry);
+        if (!(stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU))
+                cfs_atomic_inc(&percpu_cntr->lc_cntl.la_entry);
         percpu_cntr->lc_count++;
 
         if (percpu_cntr->lc_config & LPROCFS_CNTR_AVGMINMAX) {
@@ -187,8 +188,9 @@ void lprocfs_counter_add(struct lprocfs_stats *stats, int idx,
                 if (amount > percpu_cntr->lc_max)
                         percpu_cntr->lc_max = amount;
         }
-        cfs_atomic_inc(&percpu_cntr->lc_cntl.la_exit);
-        lprocfs_stats_unlock(stats);
+        if (!(stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU))
+                cfs_atomic_inc(&percpu_cntr->lc_cntl.la_exit);
+        lprocfs_stats_unlock(stats, LPROCFS_GET_SMP_ID);
 }
 EXPORT_SYMBOL(lprocfs_counter_add);
 
@@ -206,7 +208,8 @@ void lprocfs_counter_sub(struct lprocfs_stats *stats, int idx,
         smp_id = lprocfs_stats_lock(stats, LPROCFS_GET_SMP_ID);
 
         percpu_cntr = &(stats->ls_percpu[smp_id]->lp_cntr[idx]);
-        cfs_atomic_inc(&percpu_cntr->lc_cntl.la_entry);
+        if (!(stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU))
+                cfs_atomic_inc(&percpu_cntr->lc_cntl.la_entry);
         if (percpu_cntr->lc_config & LPROCFS_CNTR_AVGMINMAX) {
                 /*
                  * currently lprocfs_count_add() can only be called in thread
@@ -221,8 +224,9 @@ void lprocfs_counter_sub(struct lprocfs_stats *stats, int idx,
                 else
                         percpu_cntr->lc_sum -= amount;
         }
-        cfs_atomic_inc(&percpu_cntr->lc_cntl.la_exit);
-        lprocfs_stats_unlock(stats);
+        if (!(stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU))
+                cfs_atomic_inc(&percpu_cntr->lc_cntl.la_exit);
+        lprocfs_stats_unlock(stats, LPROCFS_GET_SMP_ID);
 }
 EXPORT_SYMBOL(lprocfs_counter_sub);
 #endif  /* LPROCFS */
diff --git a/lustre/obdclass/lprocfs_status.c b/lustre/obdclass/lprocfs_status.c
index 6926153..2a5d742 100644
--- a/lustre/obdclass/lprocfs_status.c
+++ b/lustre/obdclass/lprocfs_status.c
@@ -701,10 +701,7 @@ void lprocfs_stats_collect(struct lprocfs_stats *stats, int idx,
 
         cnt->lc_min = LC_MIN_INIT;
 
-        if (stats->ls_flags & LPROCFS_STATS_FLAG_NOPERCPU)
-                num_cpu = 1;
-        else
-                num_cpu = cfs_num_possible_cpus();
+        num_cpu = lprocfs_stats_lock(stats, LPROCFS_GET_NUM_CPU);
 
         for (i = 0; i < num_cpu; i++) {
                 percpu_cntr = &(stats->ls_percpu[i])->lp_cntr[idx];
@@ -731,6 +728,7 @@ void lprocfs_stats_collect(struct lprocfs_stats *stats, int idx,
         }
 
         cnt->lc_units = stats->ls_percpu[0]->lp_cntr[idx].lc_units;
+        lprocfs_stats_unlock(stats, LPROCFS_GET_NUM_CPU);
 }
 
 /**
@@ -1258,7 +1256,7 @@ void lprocfs_clear_stats(struct lprocfs_stats *stats)
                 }
         }
 
-        lprocfs_stats_unlock(stats);
+        lprocfs_stats_unlock(stats, LPROCFS_GET_NUM_CPU);
 }
 
 static ssize_t lprocfs_stats_seq_write(struct file *file, const char *buf,
@@ -1414,7 +1412,7 @@ void lprocfs_counter_init(struct lprocfs_stats *stats, int index,
                 c->lc_units = units;
         }
 
-        lprocfs_stats_unlock(stats);
+        lprocfs_stats_unlock(stats, LPROCFS_GET_NUM_CPU);
 }
 EXPORT_SYMBOL(lprocfs_counter_init);