5 files changed, 12 insertions, 11 deletions

diff --git a/block/bio.c b/block/bio.c
index 8c680a776171..0093bed81c0e 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1684,7 +1684,7 @@ void generic_end_io_acct(struct request_queue *q, int req_op,
         const int sgrp = op_stat_group(req_op);
         int cpu = part_stat_lock();
 
-        part_stat_add(cpu, part, ticks[sgrp], duration);
+        part_stat_add(cpu, part, nsecs[sgrp], jiffies_to_nsecs(duration));
         part_round_stats(q, cpu, part);
         part_dec_in_flight(q, part, op_is_write(req_op));
 
diff --git a/block/blk-core.c b/block/blk-core.c
index 4dbc93f43b38..cff0a60ee200 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2733,17 +2733,15 @@ void blk_account_io_done(struct request *req, u64 now)
          * containing request is enough.
          */
         if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) {
-                unsigned long duration;
                 const int sgrp = op_stat_group(req_op(req));
                 struct hd_struct *part;
                 int cpu;
 
-                duration = nsecs_to_jiffies(now - req->start_time_ns);
                 cpu = part_stat_lock();
                 part = req->part;
 
                 part_stat_inc(cpu, part, ios[sgrp]);
-                part_stat_add(cpu, part, ticks[sgrp], duration);
+                part_stat_add(cpu, part, nsecs[sgrp], now - req->start_time_ns);
                 part_round_stats(req->q, cpu, part);
                 part_dec_in_flight(req->q, part, rq_data_dir(req));
 
diff --git a/block/genhd.c b/block/genhd.c
index 8cc719a37b32..be5bab20b2ab 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1343,18 +1343,18 @@ static int diskstats_show(struct seq_file *seqf, void *v)
                            part_stat_read(hd, ios[STAT_READ]),
                            part_stat_read(hd, merges[STAT_READ]),
                            part_stat_read(hd, sectors[STAT_READ]),
-                           jiffies_to_msecs(part_stat_read(hd, ticks[STAT_READ])),
+                           (unsigned int)part_stat_read_msecs(hd, STAT_READ),
                            part_stat_read(hd, ios[STAT_WRITE]),
                            part_stat_read(hd, merges[STAT_WRITE]),
                            part_stat_read(hd, sectors[STAT_WRITE]),
-                           jiffies_to_msecs(part_stat_read(hd, ticks[STAT_WRITE])),
+                           (unsigned int)part_stat_read_msecs(hd, STAT_WRITE),
                            inflight[0],
                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
                            jiffies_to_msecs(part_stat_read(hd, time_in_queue)),
                            part_stat_read(hd, ios[STAT_DISCARD]),
                            part_stat_read(hd, merges[STAT_DISCARD]),
                            part_stat_read(hd, sectors[STAT_DISCARD]),
-                           jiffies_to_msecs(part_stat_read(hd, ticks[STAT_DISCARD]))
+                           (unsigned int)part_stat_read_msecs(hd, STAT_DISCARD)
                         );
         }
         disk_part_iter_exit(&piter);
diff --git a/block/partition-generic.c b/block/partition-generic.c
index 5a8975a1201c..d3d14e81fb12 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -136,18 +136,18 @@ ssize_t part_stat_show(struct device *dev,
                 part_stat_read(p, ios[STAT_READ]),
                 part_stat_read(p, merges[STAT_READ]),
                 (unsigned long long)part_stat_read(p, sectors[STAT_READ]),
-                jiffies_to_msecs(part_stat_read(p, ticks[STAT_READ])),
+                (unsigned int)part_stat_read_msecs(p, STAT_READ),
                 part_stat_read(p, ios[STAT_WRITE]),
                 part_stat_read(p, merges[STAT_WRITE]),
                 (unsigned long long)part_stat_read(p, sectors[STAT_WRITE]),
-                jiffies_to_msecs(part_stat_read(p, ticks[STAT_WRITE])),
+                (unsigned int)part_stat_read_msecs(p, STAT_WRITE),
                 inflight[0],
                 jiffies_to_msecs(part_stat_read(p, io_ticks)),
                 jiffies_to_msecs(part_stat_read(p, time_in_queue)),
                 part_stat_read(p, ios[STAT_DISCARD]),
                 part_stat_read(p, merges[STAT_DISCARD]),
                 (unsigned long long)part_stat_read(p, sectors[STAT_DISCARD]),
-                jiffies_to_msecs(part_stat_read(p, ticks[STAT_DISCARD])));
+                (unsigned int)part_stat_read_msecs(p, STAT_DISCARD));
 }
 
 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 57864422a2c8..25c08c6c7f99 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -83,10 +83,10 @@ struct partition {
 } __attribute__((packed));
 
 struct disk_stats {
+        u64 nsecs[NR_STAT_GROUPS];
         unsigned long sectors[NR_STAT_GROUPS];
         unsigned long ios[NR_STAT_GROUPS];
         unsigned long merges[NR_STAT_GROUPS];
-        unsigned long ticks[NR_STAT_GROUPS];
         unsigned long io_ticks;
         unsigned long time_in_queue;
 };
@@ -354,6 +354,9 @@ static inline void free_part_stats(struct hd_struct *part)
 
 #endif /* CONFIG_SMP */
 
+#define part_stat_read_msecs(part, which)                               \
+        div_u64(part_stat_read(part, nsecs[which]), NSEC_PER_MSEC)
+
 #define part_stat_read_accum(part, field)                               \
         (part_stat_read(part, field[STAT_READ]) +                       \
          part_stat_read(part, field[STAT_WRITE]) +                      \