lkml.org 
[lkml]   [2021]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH RFC 1/6] btrfs: Add inflight BIO request counter
Date
From: Michal Rostecki <mrostecki@suse.com>

Add a per-CPU inflight BIO counter to btrfs_device which stores the
number of requests currently processed by the device. This information
is going to be used in roundrobin raid1 read policy.

Signed-off-by: Michal Rostecki <mrostecki@suse.com>
---
fs/btrfs/volumes.c | 11 +++++++++--
fs/btrfs/volumes.h | 3 +++
2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3948f5b50d11..d4f452dcce95 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -376,6 +376,7 @@ void btrfs_free_device(struct btrfs_device *device)
extent_io_tree_release(&device->alloc_state);
bio_put(device->flush_bio);
btrfs_destroy_dev_zone_info(device);
+ percpu_counter_destroy(&device->inflight);
kfree(device);
}

@@ -439,6 +440,11 @@ static struct btrfs_device *__alloc_device(struct btrfs_fs_info *fs_info)
extent_io_tree_init(fs_info, &dev->alloc_state,
IO_TREE_DEVICE_ALLOC_STATE, NULL);

+ if (percpu_counter_init(&dev->inflight, 0, GFP_KERNEL)) {
+ kfree(dev);
+ return ERR_PTR(-ENOMEM);
+ }
+
return dev;
}

@@ -6305,6 +6311,7 @@ static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)

static void btrfs_end_bio(struct bio *bio)
{
+ struct btrfs_device *dev = btrfs_io_bio(bio)->device;
struct btrfs_bio *bbio = bio->bi_private;
int is_orig_bio = 0;

@@ -6312,8 +6319,6 @@ static void btrfs_end_bio(struct bio *bio)
atomic_inc(&bbio->error);
if (bio->bi_status == BLK_STS_IOERR ||
bio->bi_status == BLK_STS_TARGET) {
- struct btrfs_device *dev = btrfs_io_bio(bio)->device;
-
ASSERT(dev->bdev);
if (bio_op(bio) == REQ_OP_WRITE)
btrfs_dev_stat_inc_and_print(dev,
@@ -6331,6 +6336,7 @@ static void btrfs_end_bio(struct bio *bio)
is_orig_bio = 1;

btrfs_bio_counter_dec(bbio->fs_info);
+ percpu_counter_dec(&dev->inflight);

if (atomic_dec_and_test(&bbio->stripes_pending)) {
if (!is_orig_bio) {
@@ -6375,6 +6381,7 @@ static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
bio_set_dev(bio, dev->bdev);

btrfs_bio_counter_inc_noblocked(fs_info);
+ percpu_counter_inc(&dev->inflight);

btrfsic_submit_bio(bio);
}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 04e2b26823c2..938c5292250c 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -143,6 +143,9 @@ struct btrfs_device {
struct completion kobj_unregister;
/* For sysfs/FSID/devinfo/devid/ */
struct kobject devid_kobj;
+
+ /* I/O stats for raid1 mirror selection */
+ struct percpu_counter inflight;
};

/*
--
2.30.0
\
 
 \ /
  Last update: 2021-02-10 00:55    [W:0.285 / U:2.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site