Commit 69f457b1 authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Bjorn Helgaas
Browse files

PCI/P2PDMA: Use percpu_ref_tryget_live_rcu() inside RCU critical section 

Since pci_alloc_p2pmem() has already called rcu_read_lock(), we're in an
RCU read-side critical section and don't need to take the lock again.  Use
percpu_ref_tryget_live_rcu() instead of percpu_ref_tryget_live() to save a
few cycles.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/ab80164f4d5b32f9e6240aa4863c3a147ff9c89f.1635974126.git.christophe.jaillet@wanadoo.fr


Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarKrzysztof Wilczyński <kw@linux.com>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
parent 133bc542

drivers/pci/p2pdma.c

+1 −1
Original line number Diff line number Diff line
@@ -710,7 +710,7 @@ void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size) 
	if (!ret)

		goto out;



	if (unlikely(!percpu_ref_tryget_live(ref))) {

	if (unlikely(!percpu_ref_tryget_live_rcu(ref))) {

		gen_pool_free(p2pdma->pool, (unsigned long) ret, size);

		ret = NULL;

		goto out;