block: stop passing 'cpu' to all percpu stats methods

All of part_stat_* and related methods are used with preempt disabled,
so there is no need to pass cpu around to allow of them.  Just call
smp_processor_id() as needed.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bio.c b/block/bio.c
index 0676054..0aca870 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1668,11 +1668,12 @@ void generic_start_io_acct(struct request_queue *q, int op,
                           unsigned long sectors, struct hd_struct *part)
 {
        const int sgrp = op_stat_group(op);
-       int cpu = part_stat_lock();
 
-       part_round_stats(q, cpu, part);
-       part_stat_inc(cpu, part, ios[sgrp]);
-       part_stat_add(cpu, part, sectors[sgrp], sectors);
+       part_stat_lock();
+
+       part_round_stats(q, part);
+       part_stat_inc(part, ios[sgrp]);
+       part_stat_add(part, sectors[sgrp], sectors);
        part_inc_in_flight(q, part, op_is_write(op));
 
        part_stat_unlock();
@@ -1684,10 +1685,11 @@ void generic_end_io_acct(struct request_queue *q, int req_op,
 {
        unsigned long duration = jiffies - start_time;
        const int sgrp = op_stat_group(req_op);
-       int cpu = part_stat_lock();
 
-       part_stat_add(cpu, part, nsecs[sgrp], jiffies_to_nsecs(duration));
-       part_round_stats(q, cpu, part);
+       part_stat_lock();
+
+       part_stat_add(part, nsecs[sgrp], jiffies_to_nsecs(duration));
+       part_round_stats(q, part);
        part_dec_in_flight(q, part, op_is_write(req_op));
 
        part_stat_unlock();

diff --git a/block/blk-core.c b/block/blk-core.c
index ad59102..734b768 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -584,14 +584,14 @@ struct request *blk_get_request(struct request_queue *q, unsigned int op,
 }
 EXPORT_SYMBOL(blk_get_request);
 
-static void part_round_stats_single(struct request_queue *q, int cpu,
+static void part_round_stats_single(struct request_queue *q,
                                    struct hd_struct *part, unsigned long now,
                                    unsigned int inflight)
 {
        if (inflight) {
-               __part_stat_add(cpu, part, time_in_queue,
+               __part_stat_add(part, time_in_queue,
                                inflight * (now - part->stamp));
-               __part_stat_add(cpu, part, io_ticks, (now - part->stamp));
+               __part_stat_add(part, io_ticks, (now - part->stamp));
        }
        part->stamp = now;
 }
@@ -599,7 +599,6 @@ static void part_round_stats_single(struct request_queue *q, int cpu,
 /**
  * part_round_stats() - Round off the performance stats on a struct disk_stats.
  * @q: target block queue
- * @cpu: cpu number for stats access
  * @part: target partition
  *
  * The average IO queue length and utilisation statistics are maintained
@@ -613,7 +612,7 @@ static void part_round_stats_single(struct request_queue *q, int cpu,
  * /proc/diskstats.  This accounts immediately for all queue usage up to
  * the current jiffies and restarts the counters again.
  */
-void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part)
+void part_round_stats(struct request_queue *q, struct hd_struct *part)
 {
        struct hd_struct *part2 = NULL;
        unsigned long now = jiffies;
@@ -635,9 +634,9 @@ void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part)
        part_in_flight(q, part, inflight);
 
        if (stats & 2)
-               part_round_stats_single(q, cpu, part2, now, inflight[1]);
+               part_round_stats_single(q, part2, now, inflight[1]);
        if (stats & 1)
-               part_round_stats_single(q, cpu, part, now, inflight[0]);
+               part_round_stats_single(q, part, now, inflight[0]);
 }
 EXPORT_SYMBOL_GPL(part_round_stats);
 
@@ -1362,11 +1361,10 @@ void blk_account_io_completion(struct request *req, unsigned int bytes)
        if (blk_do_io_stat(req)) {
                const int sgrp = op_stat_group(req_op(req));
                struct hd_struct *part;
-               int cpu;
 
-               cpu = part_stat_lock();
+               part_stat_lock();
                part = req->part;
-               part_stat_add(cpu, part, sectors[sgrp], bytes >> 9);
+               part_stat_add(part, sectors[sgrp], bytes >> 9);
                part_stat_unlock();
        }
 }
@@ -1381,14 +1379,13 @@ void blk_account_io_done(struct request *req, u64 now)
        if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) {
                const int sgrp = op_stat_group(req_op(req));
                struct hd_struct *part;
-               int cpu;
 
-               cpu = part_stat_lock();
+               part_stat_lock();
                part = req->part;
 
-               part_stat_inc(cpu, part, ios[sgrp]);
-               part_stat_add(cpu, part, nsecs[sgrp], now - req->start_time_ns);
-               part_round_stats(req->q, cpu, part);
+               part_stat_inc(part, ios[sgrp]);
+               part_stat_add(part, nsecs[sgrp], now - req->start_time_ns);
+               part_round_stats(req->q, part);
                part_dec_in_flight(req->q, part, rq_data_dir(req));
 
                hd_struct_put(part);
@@ -1400,16 +1397,15 @@ void blk_account_io_start(struct request *rq, bool new_io)
 {
        struct hd_struct *part;
        int rw = rq_data_dir(rq);
-       int cpu;
 
        if (!blk_do_io_stat(rq))
                return;
 
-       cpu = part_stat_lock();
+       part_stat_lock();
 
        if (!new_io) {
                part = rq->part;
-               part_stat_inc(cpu, part, merges[rw]);
+               part_stat_inc(part, merges[rw]);
        } else {
                part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
                if (!hd_struct_try_get(part)) {
@@ -1424,7 +1420,7 @@ void blk_account_io_start(struct request *rq, bool new_io)
                        part = &rq->rq_disk->part0;
                        hd_struct_get(part);
                }
-               part_round_stats(rq->q, cpu, part);
+               part_round_stats(rq->q, part);
                part_inc_in_flight(rq->q, part, rw);
                rq->part = part;
        }

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 4431da6..a120d59 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -685,12 +685,11 @@ static void blk_account_io_merge(struct request *req)
 {
        if (blk_do_io_stat(req)) {
                struct hd_struct *part;
-               int cpu;
 
-               cpu = part_stat_lock();
+               part_stat_lock();
                part = req->part;
 
-               part_round_stats(req->q, cpu, part);
+               part_round_stats(req->q, part);
                part_dec_in_flight(req->q, part, rq_data_dir(req));
 
                hd_struct_put(part);

diff --git a/block/genhd.c b/block/genhd.c
index 0145bcb..2fe00cf 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1326,7 +1326,6 @@ static int diskstats_show(struct seq_file *seqf, void *v)
        struct hd_struct *hd;
        char buf[BDEVNAME_SIZE];
        unsigned int inflight[2];
-       int cpu;
 
        /*
        if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
@@ -1338,8 +1337,8 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 
        disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
        while ((hd = disk_part_iter_next(&piter))) {
-               cpu = part_stat_lock();
-               part_round_stats(gp->queue, cpu, hd);
+               part_stat_lock();
+               part_round_stats(gp->queue, hd);
                part_stat_unlock();
                part_in_flight(gp->queue, hd, inflight);
                seq_printf(seqf, "%4d %7d %s "

diff --git a/block/partition-generic.c b/block/partition-generic.c
index 5f8db5c..7e663cf 100644 (file)
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -121,10 +121,9 @@ ssize_t part_stat_show(struct device *dev,
        struct hd_struct *p = dev_to_part(dev);
        struct request_queue *q = part_to_disk(p)->queue;
        unsigned int inflight[2];
-       int cpu;
 
-       cpu = part_stat_lock();
-       part_round_stats(q, cpu, p);
+       part_stat_lock();
+       part_round_stats(q, p);
        part_stat_unlock();
        part_in_flight(q, p, inflight);
        return sprintf(buf,

diff --git a/drivers/md/md.c b/drivers/md/md.c
index fc488cb..9a0a1e0 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -334,7 +334,6 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
        const int sgrp = op_stat_group(bio_op(bio));
        struct mddev *mddev = q->queuedata;
        unsigned int sectors;
-       int cpu;
 
        blk_queue_split(q, &bio);
 
@@ -359,9 +358,9 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 
        md_handle_request(mddev, bio);
 
-       cpu = part_stat_lock();
-       part_stat_inc(cpu, &mddev->gendisk->part0, ios[sgrp]);
-       part_stat_add(cpu, &mddev->gendisk->part0, sectors[sgrp], sectors);
+       part_stat_lock();
+       part_stat_inc(&mddev->gendisk->part0, ios[sgrp]);
+       part_stat_add(&mddev->gendisk->part0, sectors[sgrp], sectors);
        part_stat_unlock();
 
        return BLK_QC_T_NONE;

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 0c5ee17..1677cd2 100644 (file)
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -295,8 +295,8 @@ extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 #define part_stat_lock()       ({ rcu_read_lock(); get_cpu(); })
 #define part_stat_unlock()     do { put_cpu(); rcu_read_unlock(); } while (0)
 
-#define __part_stat_add(cpu, part, field, addnd)                       \
-       (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
+#define __part_stat_add(part, field, addnd)                            \
+       (per_cpu_ptr((part)->dkstats, smp_processor_id())->field += (addnd))
 
 #define part_stat_read(part, field)                                    \
 ({                                                                     \
@@ -333,7 +333,7 @@ static inline void free_part_stats(struct hd_struct *part)
 #define part_stat_lock()       ({ rcu_read_lock(); 0; })
 #define part_stat_unlock()     rcu_read_unlock()
 
-#define __part_stat_add(cpu, part, field, addnd)                               \
+#define __part_stat_add(part, field, addnd)                            \
        ((part)->dkstats.field += addnd)
 
 #define part_stat_read(part, field)    ((part)->dkstats.field)
@@ -362,19 +362,19 @@ static inline void free_part_stats(struct hd_struct *part)
         part_stat_read(part, field[STAT_WRITE]) +                      \
         part_stat_read(part, field[STAT_DISCARD]))
 
-#define part_stat_add(cpu, part, field, addnd) do {                    \
-       __part_stat_add((cpu), (part), field, addnd);                   \
+#define part_stat_add(part, field, addnd)      do {                    \
+       __part_stat_add((part), field, addnd);                          \
        if ((part)->partno)                                             \
-               __part_stat_add((cpu), &part_to_disk((part))->part0,    \
+               __part_stat_add(&part_to_disk((part))->part0,           \
                                field, addnd);                          \
 } while (0)
 
-#define part_stat_dec(cpu, gendiskp, field)                            \
-       part_stat_add(cpu, gendiskp, field, -1)
-#define part_stat_inc(cpu, gendiskp, field)                            \
-       part_stat_add(cpu, gendiskp, field, 1)
-#define part_stat_sub(cpu, gendiskp, field, subnd)                     \
-       part_stat_add(cpu, gendiskp, field, -subnd)
+#define part_stat_dec(gendiskp, field)                                 \
+       part_stat_add(gendiskp, field, -1)
+#define part_stat_inc(gendiskp, field)                                 \
+       part_stat_add(gendiskp, field, 1)
+#define part_stat_sub(gendiskp, field, subnd)                          \
+       part_stat_add(gendiskp, field, -subnd)
 
 void part_in_flight(struct request_queue *q, struct hd_struct *part,
                    unsigned int inflight[2]);
@@ -399,7 +399,7 @@ static inline void free_part_info(struct hd_struct *part)
 }
 
 /* block/blk-core.c */
-extern void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part);
+extern void part_round_stats(struct request_queue *q, struct hd_struct *part);
 
 /* block/genhd.c */
 extern void device_add_disk(struct device *parent, struct gendisk *disk,