diff options
| author | Shi Hao <i.shihao.999@gmail.com> | 2025-11-01 11:14:22 +0530 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-11-03 08:15:54 -0700 |
| commit | 77220f6d18a22b0b5d73b5d2156609b0aa21a7c5 (patch) | |
| tree | dc0b0e3983db734bad2dec1f66f9d066cde1ba54 | |
| parent | e48886b9d668d80be24e37345bd0904e9138473c (diff) | |
drbd: replace kmap() with kmap_local_page() in receiver path
Use kmap_local_page() instead of kmap() to avoid
CPU contention.
kmap() uses a global set of mapping slots that can cause contention
between multiple CPUs, while kmap_local_page() uses per-CPU slots
eliminating this contention. It also ensures non-sleeping operation
and provides better cache locality.
Convert kmap() to kmap_local_page() as it aligns with ongoing
kernel efforts to modernize kmap() usage for better multi-core
scalability.
Signed-off-by: Shi Hao <i.shihao.999@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index caaf2781136d..14821420ea50 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1736,13 +1736,13 @@ read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector, page = peer_req->pages; page_chain_for_each(page) { unsigned len = min_t(int, ds, PAGE_SIZE); - data = kmap(page); + data = kmap_local_page(page); err = drbd_recv_all_warn(peer_device->connection, data, len); if (drbd_insert_fault(device, DRBD_FAULT_RECEIVE)) { drbd_err(device, "Fault injection: Corrupting data on receive\n"); data[0] = data[0] ^ (unsigned long)-1; } - kunmap(page); + kunmap_local(data); if (err) { drbd_free_peer_req(device, peer_req); return NULL; @@ -1777,7 +1777,7 @@ static int drbd_drain_block(struct drbd_peer_device *peer_device, int data_size) page = drbd_alloc_pages(peer_device, 1, 1); - data = kmap(page); + data = kmap_local_page(page); while (data_size) { unsigned int len = min_t(int, data_size, PAGE_SIZE); @@ -1786,7 +1786,7 @@ static int drbd_drain_block(struct drbd_peer_device *peer_device, int data_size) break; data_size -= len; } - kunmap(page); + kunmap_local(data); drbd_free_pages(peer_device->device, page); return err; } |