diff mbox series

common/mlx5: reduce size of netlink buffer

Message ID 20200422223000.16602-1-stephen@networkplumber.org (mailing list archive)
State Superseded, archived
Delegated to: Raslan Darawsheh
Headers show
Series common/mlx5: reduce size of netlink buffer | expand

Checks

Context Check Description
ci/iol-testing fail Testing issues
ci/iol-mellanox-Performance fail Performance Testing issues
ci/Intel-compilation fail Compilation issues
ci/iol-nxp-Performance success Performance Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/checkpatch success coding style OK

Commit Message

Stephen Hemminger April 22, 2020, 10:30 p.m. UTC
Since the driver is just using netlink to receive acknowledgements
for command requests, having a large (32K) buffer is unnecessary.
Allocating large buffers on stack will break in application is
using smaller per-thread stacks.

It looks like original code intended to use a smaller buffer
for the read than the socket, so keep that set of defines.

Fixes: ccdcba53a3f4 ("net/mlx5: use Netlink to add/remove MAC addresses")
Cc: nelio.laranjeiro@6wind.com
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/common/mlx5/mlx5_nl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Slava Ovsiienko April 28, 2020, 9:34 a.m. UTC | #1
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Stephen Hemminger
> Sent: Thursday, April 23, 2020 1:30
> To: dev@dpdk.org
> Cc: Stephen Hemminger <stephen@networkplumber.org>; Nélio Laranjeiro
> <nelio.laranjeiro@6wind.com>
> Subject: [dpdk-dev] [PATCH] common/mlx5: reduce size of netlink buffer
> 
> Since the driver is just using netlink to receive acknowledgements for
> command requests, having a large (32K) buffer is unnecessary.

Not for acknowledgements only, it is also used to get the dumps for the MAC
addresses and Infiniband device ports, as we know dump operations might
merge replies into one large message, smaller buffer might prevent the
dump receiving. What do you think about the buffer allocation  on the device
initialization and storing that somewhere in the device structure?

With best regards,
Slava

> Allocating large buffers on stack will break in application is using smaller per-
> thread stacks.
> 
> It looks like original code intended to use a smaller buffer for the read than
> the socket, so keep that set of defines.
> 
> Fixes: ccdcba53a3f4 ("net/mlx5: use Netlink to add/remove MAC addresses")
> Cc: nelio.laranjeiro@6wind.com
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
>  drivers/common/mlx5/mlx5_nl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/common/mlx5/mlx5_nl.c
> b/drivers/common/mlx5/mlx5_nl.c index d9f0d4129e35..847e78dbcea6
> 100644
> --- a/drivers/common/mlx5/mlx5_nl.c
> +++ b/drivers/common/mlx5/mlx5_nl.c
> @@ -28,7 +28,7 @@
> 
> 
>  /* Size of the buffer to receive kernel messages */ -#define
> MLX5_NL_BUF_SIZE (32 * 1024)
> +#define MLX5_NL_BUF_SIZE 4096
>  /* Send buffer size for the Netlink socket */  #define MLX5_SEND_BUF_SIZE
> 32768
>  /* Receive buffer size for the Netlink socket */ @@ -330,7 +330,7 @@
> mlx5_nl_recv(int nlsk_fd, uint32_t sn, int (*cb)(struct nlmsghdr *, void *arg),
>  	     void *arg)
>  {
>  	struct sockaddr_nl sa;
> -	char buf[MLX5_RECV_BUF_SIZE];
> +	char buf[MLX5_NL_BUF_SIZE];
>  	struct iovec iov = {
>  		.iov_base = buf,
>  		.iov_len = sizeof(buf),
> --
> 2.20.1
diff mbox series

Patch

diff --git a/drivers/common/mlx5/mlx5_nl.c b/drivers/common/mlx5/mlx5_nl.c
index d9f0d4129e35..847e78dbcea6 100644
--- a/drivers/common/mlx5/mlx5_nl.c
+++ b/drivers/common/mlx5/mlx5_nl.c
@@ -28,7 +28,7 @@ 
 
 
 /* Size of the buffer to receive kernel messages */
-#define MLX5_NL_BUF_SIZE (32 * 1024)
+#define MLX5_NL_BUF_SIZE 4096
 /* Send buffer size for the Netlink socket */
 #define MLX5_SEND_BUF_SIZE 32768
 /* Receive buffer size for the Netlink socket */
@@ -330,7 +330,7 @@  mlx5_nl_recv(int nlsk_fd, uint32_t sn, int (*cb)(struct nlmsghdr *, void *arg),
 	     void *arg)
 {
 	struct sockaddr_nl sa;
-	char buf[MLX5_RECV_BUF_SIZE];
+	char buf[MLX5_NL_BUF_SIZE];
 	struct iovec iov = {
 		.iov_base = buf,
 		.iov_len = sizeof(buf),