LU-1727 lprocfs: fix an old assertion

lprocfs_counter_add() can be called in interrupt context, as a memory
allocation can trigger memory shrinker call ldlm_pool_shrink(), which
calls lprocfs_counter_add().

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I0f5d3e07c234f7d615ca87761a7bd6367e72beac
Reviewed-on: http://review.whamcloud.com/3729
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/lvfs/lvfs_lib.c b/lustre/lvfs/lvfs_lib.c
index 625ab15..99334a2 100644 (file)
--- a/lustre/lvfs/lvfs_lib.c
+++ b/lustre/lvfs/lvfs_lib.c
@@ -95,10 +95,16 @@ void lprocfs_counter_add(struct lprocfs_stats *stats, int idx,
         percpu_cntr->lc_count++;
 
         if (percpu_cntr->lc_config & LPROCFS_CNTR_AVGMINMAX) {
-                /* see comment in lprocfs_counter_sub */
-                LASSERT(!cfs_in_interrupt());
-
-                percpu_cntr->lc_sum += amount;
+               /*
+                * lprocfs_counter_add() can be called in interrupt context,
+                * as memory allocation could trigger memory shrinker call
+                * ldlm_pool_shrink(), which calls lprocfs_counter_add().
+                * LU-1727.
+                */
+               if (cfs_in_interrupt())
+                       percpu_cntr->lc_sum_irq += amount;
+               else
+                       percpu_cntr->lc_sum += amount;
                 if (percpu_cntr->lc_config & LPROCFS_CNTR_STDDEV)
                         percpu_cntr->lc_sumsquare += (__s64)amount * amount;
                 if (amount < percpu_cntr->lc_min)
@@ -131,14 +137,13 @@ void lprocfs_counter_sub(struct lprocfs_stats *stats, int idx, long amount)
         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
-                 * context; sometimes we use RCU callbacks to free memory
-                 * which calls lprocfs_counter_sub(), and RCU callbacks may
-                 * execute in softirq context - right now that's the only case
-                 * we're in softirq context here, use separate counter for that.
-                 * bz20650.
-                 */
+               /*
+                * Sometimes we use RCU callbacks to free memory which calls
+                * lprocfs_counter_sub(), and RCU callbacks may execute in
+                * softirq context - right now that's the only case we're in
+                * softirq context here, use separate counter for that.
+                * bz20650.
+                */
                 if (cfs_in_interrupt())
                         percpu_cntr->lc_sum_irq -= amount;
                 else