gru: collect per-context user statistics

Collect GRU statistics for each user GRU context.  Statistics are kept for
TLB misses & content resource contention.  Add user request for retrieving
the statistics.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 6d0681236db5..cdd151b30dc7 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -498,6 +498,7 @@ irqreturn_t gru_intr(int irq, void *dev_id)
                  */
                 if (!gts->ts_force_cch_reload &&
                                         down_read_trylock(&gts->ts_mm->mmap_sem)) {
+                        gts->ustats.fmm_tlbdropin++;
                         gru_try_dropin(gts, tfh, NULL);
                         up_read(&gts->ts_mm->mmap_sem);
                 } else {
@@ -516,6 +517,7 @@ static int gru_user_dropin(struct gru_thread_state *gts,
         struct gru_mm_struct *gms = gts->ts_gms;
         int ret;
 
+        gts->ustats.upm_tlbdropin++;
         while (1) {
                 wait_event(gms->ms_wait_queue,
                            atomic_read(&gms->ms_range_active) == 0);
@@ -719,6 +721,31 @@ int gru_user_flush_tlb(unsigned long arg)
 }
 
 /*
+ * Fetch GSEG statisticss
+ */
+long gru_get_gseg_statistics(unsigned long arg)
+{
+        struct gru_thread_state *gts;
+        struct gru_get_gseg_statistics_req req;
+
+        if (copy_from_user(&req, (void __user *)arg, sizeof(req)))
+                return -EFAULT;
+
+        gts = gru_find_lock_gts(req.gseg);
+        if (gts) {
+                memcpy(&req.stats, &gts->ustats, sizeof(gts->ustats));
+                gru_unlock_gts(gts);
+        } else {
+                memset(&req.stats, 0, sizeof(gts->ustats));
+        }
+
+        if (copy_to_user((void __user *)arg, &req, sizeof(req)))
+                return -EFAULT;
+
+        return 0;
+}
+
+/*
  * Register the current task as the user of the GSEG slice.
  * Needed for TLB fault interrupt targeting.
  */