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>

5 files changed, 52 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.
  */
diff --git a/drivers/misc/sgi-gru/grufile.c b/drivers/misc/sgi-gru/grufile.c
index e22012db239e..0d1c8b8c1c12 100644
--- a/drivers/misc/sgi-gru/grufile.c
+++ b/drivers/misc/sgi-gru/grufile.c
@@ -251,6 +251,9 @@ static long gru_file_unlocked_ioctl(struct file *file, unsigned int req,
         case GRU_USER_CALL_OS:
                 err = gru_handle_user_call_os(arg);
                 break;
+        case GRU_GET_GSEG_STATISTICS:
+                err = gru_get_gseg_statistics(arg);
+                break;
         case GRU_KTEST:
                 err = gru_ktest(arg);
                 break;
diff --git a/drivers/misc/sgi-gru/grulib.h b/drivers/misc/sgi-gru/grulib.h
index 87586551d16f..c5865dd19eec 100644
--- a/drivers/misc/sgi-gru/grulib.h
+++ b/drivers/misc/sgi-gru/grulib.h
@@ -50,6 +50,9 @@
 /* For dumpping GRU chiplet state */
 #define GRU_DUMP_CHIPLET_STATE          _IOWR(GRU_IOCTL_NUM, 11, void *)
 
+/* For getting gseg statistics */
+#define GRU_GET_GSEG_STATISTICS         _IOWR(GRU_IOCTL_NUM, 12, void *)
+
 /* For user TLB flushing (primarily for tests) */
 #define GRU_USER_FLUSH_TLB              _IOWR(GRU_IOCTL_NUM, 50, void *)
 
@@ -61,6 +64,21 @@
 
 #define CONTEXT_WINDOW_BYTES(th)        (GRU_GSEG_PAGESIZE * (th))
 #define THREAD_POINTER(p, th)           (p + GRU_GSEG_PAGESIZE * (th))
+#define GSEG_START(cb)                  ((void *)((unsigned long)(cb) & ~(GRU_GSEG_PAGESIZE - 1)))
+
+/*
+ * Statictics kept on a per-GTS basis.
+ */
+struct gts_statistics {
+        unsigned long   fmm_tlbdropin;
+        unsigned long   upm_tlbdropin;
+        unsigned long   context_stolen;
+};
+
+struct gru_get_gseg_statistics_req {
+        unsigned long           gseg;
+        struct gts_statistics   stats;
+};
 
 /*
  * Structure used to pass TLB flush parameters to the driver
diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index e38a0f1775ff..347004e4f591 100644
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -744,6 +744,7 @@ void gru_steal_context(struct gru_thread_state *gts, int blade_id)
         spin_unlock(&blade->bs_lock);
 
         if (ngts) {
+                gts->ustats.context_stolen++;
                 ngts->ts_steal_jiffies = jiffies;
                 gru_unload_context(ngts, is_kernel_context(ngts) ? 0 : 1);
                 gts_stolen(ngts, blade);
diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h
index 9761bfee8669..63b76e2732ff 100644
--- a/drivers/misc/sgi-gru/grutables.h
+++ b/drivers/misc/sgi-gru/grutables.h
@@ -148,6 +148,7 @@
 #include <linux/wait.h>
 #include <linux/mmu_notifier.h>
 #include "gru.h"
+#include "grulib.h"
 #include "gruhandles.h"
 
 extern struct gru_stats_s gru_stats;
@@ -388,6 +389,7 @@ struct gru_thread_state {
                                                           allocated CB */
         int                     ts_data_valid;  /* Indicates if ts_gdata has
                                                    valid data */
+        struct gts_statistics   ustats;         /* User statistics */
         unsigned long           ts_gdata[0];    /* save area for GRU data (CB,
                                                    DS, CBE) */
 };
@@ -641,6 +643,7 @@ extern void gru_tgh_flush_init(struct gru_state *gru);
 extern int gru_kservices_init(void);
 extern void gru_kservices_exit(void);
 extern int gru_dump_chiplet_request(unsigned long arg);
+extern long gru_get_gseg_statistics(unsigned long arg);
 extern irqreturn_t gru_intr(int irq, void *dev_id);
 extern int gru_handle_user_call_os(unsigned long address);
 extern int gru_user_flush_tlb(unsigned long arg);