[PATCH 2/2] RDMA/pvrdma: Use non-atomic bitmap functions when possible
From: Christophe JAILLET <hidden>
Date: 2021-11-25 20:07:55
Also in:
kernel-janitors, lkml
Subsystem:
infiniband subsystem, the rest, vmware pvrdma driver · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds, Bryan Tan, Vishnu Dasa
In 'pvrdma_uar_table_init()', the 'tbl->table' bitmap has just been allocated, so no concurrent accesses can occur. The other accesses to the 'tbl->table' bitmap are protected by the 'tbl->lock' spinlock, so no concurrent accesses can happen. So prefer the non-atomic '__[set|clear]_bit()' functions to save a few cycles. Signed-off-by: Christophe JAILLET <redacted> --- drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c
index 21ef3fb39915..9a4de962e947 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c@@ -68,7 +68,7 @@ int pvrdma_uar_table_init(struct pvrdma_dev *dev) return -ENOMEM; /* 0th UAR is taken by the device. */ - set_bit(0, tbl->table); + __set_bit(0, tbl->table); return 0; }
@@ -100,7 +100,7 @@ int pvrdma_uar_alloc(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar) return -ENOMEM; } - set_bit(obj, tbl->table); + __set_bit(obj, tbl->table); obj |= tbl->top; spin_unlock_irqrestore(&tbl->lock, flags);
@@ -120,7 +120,7 @@ void pvrdma_uar_free(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar) obj = uar->index & (tbl->max - 1); spin_lock_irqsave(&tbl->lock, flags); - clear_bit(obj, tbl->table); + __clear_bit(obj, tbl->table); tbl->last = min(tbl->last, obj); tbl->top = (tbl->top + tbl->max) & tbl->mask; spin_unlock_irqrestore(&tbl->lock, flags);
--
2.30.2