Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755706Ab0DOABJ (ORCPT ); Wed, 14 Apr 2010 20:01:09 -0400 Received: from mga02.intel.com ([134.134.136.20]:57001 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754246Ab0DOABH (ORCPT ); Wed, 14 Apr 2010 20:01:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.52,208,1270450800"; d="scan'208";a="613233266" From: "Sean Hefty" To: , Cc: , , , , , , , References: <20100412100744.5302.92442.sendpatchset@localhost.localdomain> <20100412100816.5302.74919.sendpatchset@localhost.localdomain> <201004130121.o3D1Lhh7099571@www262.sakura.ne.jp> <4BC41994.7030707@redhat.com> <4BC42FE0.4040601@redhat.com> <201004132207.GAJ52684.OJFtMQVFHOSFLO@I-love.SAKURA.ne.jp> <21DAC78125424ED291B5D6477CFF9657@amr.corp.intel.com> <201004140201.o3E21Aqn075978@www262.sakura.ne.jp> Subject: RE: [PATCH] Infiniband: Randomize local port allocation. Date: Wed, 14 Apr 2010 17:01:04 -0700 Message-ID: <195EB1AD388F455AA386EB214FCD09F4@amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcrbdmtcPmCctRLhTdemusUyBy5YvAAtq4TA In-Reply-To: <201004140201.o3E21Aqn075978@www262.sakura.ne.jp> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2941 Lines: 105 >[PATCH] Infiniband: Randomize local port allocation. > >Randomize local port allocation in a way sctp_get_port_local() does. > >Signed-off-by: Tetsuo Handa Thanks for fixing this long outstanding issue. :) The latest patch looks correct and passed some simple tests that I ran against it. One comment below, which I didn't catch before: >--- > drivers/infiniband/core/cma.c | 69 ++++++++++++++--------------------------- >- > 1 file changed, 24 insertions(+), 45 deletions(-) > >--- linux-2.6.34-rc4.orig/drivers/infiniband/core/cma.c >+++ linux-2.6.34-rc4/drivers/infiniband/core/cma.c >@@ -79,7 +79,6 @@ static DEFINE_IDR(sdp_ps); > static DEFINE_IDR(tcp_ps); > static DEFINE_IDR(udp_ps); > static DEFINE_IDR(ipoib_ps); >-static int next_port; > > struct cma_device { > struct list_head list; >@@ -1970,47 +1969,32 @@ err1: > > static int cma_alloc_any_port(struct idr *ps, struct rdma_id_private *id_priv) > { >- struct rdma_bind_list *bind_list; >- int port, ret, low, high; >- >- bind_list = kzalloc(sizeof *bind_list, GFP_KERNEL); >- if (!bind_list) >- return -ENOMEM; >- >-retry: >- /* FIXME: add proper port randomization per like inet_csk_get_port */ >- do { >- ret = idr_get_new_above(ps, bind_list, next_port, &port); >- } while ((ret == -EAGAIN) && idr_pre_get(ps, GFP_KERNEL)); >- >- if (ret) >- goto err1; >+ static unsigned int last_used_port; >+ int low, high, remaining; >+ unsigned int rover; > > inet_get_local_port_range(&low, &high); >- if (port > high) { >- if (next_port != low) { >- idr_remove(ps, port); >- next_port = low; >- goto retry; >+ remaining = (high - low) + 1; >+ rover = net_random() % remaining + low; >+ do { >+ rover++; >+ if ((rover < low) || (rover > high)) >+ rover = low; Assuming that we're likely to pick a valid port on the first try, it would be more efficient to move the above 3 lines to the end of the while loop. >+ if (last_used_port != rover && >+ !idr_find(ps, (unsigned short) rover)) { >+ int ret = cma_alloc_port(ps, id_priv, rover); >+ /* >+ * Remember previously used port number in order to >+ * avoid re-using same port immediately after it is >+ * closed. >+ */ >+ if (!ret) >+ last_used_port = rover; >+ if (ret != -EADDRNOTAVAIL) >+ return ret; > } >- ret = -EADDRNOTAVAIL; >- goto err2; >- } >- >- if (port == high) >- next_port = low; >- else >- next_port = port + 1; >- >- bind_list->ps = ps; >- bind_list->port = (unsigned short) port; >- cma_bind_port(bind_list, id_priv); >- return 0; >-err2: >- idr_remove(ps, port); >-err1: >- kfree(bind_list); >- return ret; >+ } while (--remaining > 0); >+ return -EADDRNOTAVAIL; > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/