From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hal Rosenstock Subject: [PATCH infiniband-diags] query_smp.c: Avoid busy looping in process_one_recv Date: Thu, 16 Apr 2015 10:26:24 -0400 Message-ID: <552FC690.1010807@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ira Weiny Cc: Vladimir Koushnir , "linux-rdma (linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org)" List-Id: linux-rdma@vger.kernel.org From: Vladimir Koushnir Date: Thu, 16 Apr 2015 14:11:16 +0300 Today, process_one_recv calls umad_recv with zero timeout. That means umad_recv will use non-blocking read() without polling, In many cases, this causes busy loop. In the fix, umad_recv is invoked with -1 (infinite timeout) and the read() will occur only when poll exits. Also, no longer need to check for EWOULDBLOCK. Signed-off-by: Vladimir Koushnir Signed-off-by: Hal Rosenstock --- libibnetdisc/src/query_smp.c | 2 +- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/libibnetdisc/src/query_smp.c b/libibnetdisc/src/query_smp.c index 28620b4..8f179e4 100644 --- a/libibnetdisc/src/query_smp.c +++ b/libibnetdisc/src/query_smp.c @@ -171,9 +171,7 @@ static int process_one_recv(smp_engine_t * engine) /* wait for the next message */ if ((rc = umad_recv(engine->umad_fd, umad, &length, - 0)) < 0) { - if (rc == -EWOULDBLOCK) - return 0; + -1)) < 0) { IBND_ERROR("umad_recv failed: %d\n", rc); return -1; } -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html