[PATCH v3 1/1] net/rds: suppress page allocation failure error in recv buffer refill

[PATCH v3 1/1] net/rds: suppress page allocation failure error in recv buffer refill

[Manjunath Patil]

RDS/IB tries to refill the recv buffer in softirq context using
GFP_NOWAIT flag. However alloc failure is handled by queueing a work to
refill the recv buffer with GFP_KERNEL flag. This means failure to
allocate with GFP_NOWAIT isn't fatal. Do not print the PAF warnings if
softirq context fails to refill the recv buffer. We will see the PAF
warnings when worker also fails to allocate.

Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
---
v3:
 - remove pr_warn_ratelimited() when softirq context fails to allocate

v2:
 - change pr_warn once a day to pr_warn_ratelimited()

 net/rds/ib_recv.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index 694d411dc72f..3cffcec5fb37 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -310,8 +310,8 @@ static int rds_ib_recv_refill_one(struct rds_connection *conn,
 	struct rds_ib_connection *ic = conn->c_transport_data;
 	struct ib_sge *sge;
 	int ret = -ENOMEM;
-	gfp_t slab_mask = GFP_NOWAIT;
-	gfp_t page_mask = GFP_NOWAIT;
+	gfp_t slab_mask = gfp;
+	gfp_t page_mask = gfp;
 
 	if (gfp & __GFP_DIRECT_RECLAIM) {
 		slab_mask = GFP_KERNEL;
@@ -1020,7 +1020,7 @@ void rds_ib_recv_cqe_handler(struct rds_ib_connection *ic,
 		rds_ib_stats_inc(s_ib_rx_ring_empty);
 
 	if (rds_ib_ring_low(&ic->i_recv_ring)) {
-		rds_ib_recv_refill(conn, 0, GFP_NOWAIT);
+		rds_ib_recv_refill(conn, 0, GFP_NOWAIT | __GFP_NOWARN);
 		rds_ib_stats_inc(s_ib_rx_refill_from_cq);
 	}
 }
-- 
2.27.0.112.g101b320

Re: [PATCH v3 1/1] net/rds: suppress page allocation failure error in recv buffer refill

[Jakub Kicinski]

On Tue,  6 Oct 2020 14:31:37 -0700 Manjunath Patil wrote:
> RDS/IB tries to refill the recv buffer in softirq context using
> GFP_NOWAIT flag. However alloc failure is handled by queueing a work to
> refill the recv buffer with GFP_KERNEL flag. This means failure to
> allocate with GFP_NOWAIT isn't fatal. Do not print the PAF warnings if
> softirq context fails to refill the recv buffer. We will see the PAF
> warnings when worker also fails to allocate.
> 
> Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
> Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>

Applied to net-next, thanks!