{"id":815940,"url":"http://patchwork.ozlabs.org/api/patches/815940/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/patch/20170919232709.14690-3-edumazet@google.com/","project":{"id":7,"url":"http://patchwork.ozlabs.org/api/projects/7/?format=json","name":"Linux network development","link_name":"netdev","list_id":"netdev.vger.kernel.org","list_email":"netdev@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170919232709.14690-3-edumazet@google.com>","list_archive_url":null,"date":"2017-09-19T23:27:04","name":"[v2,net-next,2/7] kobject: copy env blob in one go","commit_ref":null,"pull_url":null,"state":"accepted","archived":true,"hash":"46b7f8482bd2765e61cb865465631fd425e90ecd","submitter":{"id":13357,"url":"http://patchwork.ozlabs.org/api/people/13357/?format=json","name":"Eric Dumazet","email":"edumazet@google.com"},"delegate":{"id":34,"url":"http://patchwork.ozlabs.org/api/users/34/?format=json","username":"davem","first_name":"David","last_name":"Miller","email":"davem@davemloft.net"},"mbox":"http://patchwork.ozlabs.org/project/netdev/patch/20170919232709.14690-3-edumazet@google.com/mbox/","series":[{"id":3987,"url":"http://patchwork.ozlabs.org/api/series/3987/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/list/?series=3987","date":"2017-09-19T23:27:02","name":"net: speedup netns create/delete time","version":2,"mbox":"http://patchwork.ozlabs.org/series/3987/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/815940/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/815940/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=netdev-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org; dkim=pass (2048-bit key;\n\tunprotected) header.d=google.com header.i=@google.com\n\theader.b=\"TRkIXkEv\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xxfD964gTz9sPr\n\tfor ;\n\tWed, 20 Sep 2017 09:27:21 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1751722AbdISX1U (ORCPT );\n\tTue, 19 Sep 2017 19:27:20 -0400","from mail-pg0-f41.google.com ([74.125.83.41]:47873 \"EHLO\n\tmail-pg0-f41.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751619AbdISX1S (ORCPT\n\t); Tue, 19 Sep 2017 19:27:18 -0400","by mail-pg0-f41.google.com with SMTP id d8so675490pgt.4\n\tfor ; Tue, 19 Sep 2017 16:27:17 -0700 (PDT)","from localhost ([2620:15c:2cb:201:58bc:17b0:6372:1d5f])\n\tby smtp.gmail.com with ESMTPSA id\n\t72sm5334474pfj.102.2017.09.19.16.27.16\n\t(version=TLS1_2 cipher=AES128-SHA bits=128/128);\n\tTue, 19 Sep 2017 16:27:16 -0700 (PDT)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=google.com; s=20161025;\n\th=from:to:cc:subject:date:message-id:in-reply-to:references;\n\tbh=/DRYr3B/EYZ677PMfEaLYMwAChuX2oMu0c9/fIaCpkc=;\n\tb=TRkIXkEvtwaxqnmo9k46BhkFt7iP2c3k1zJmwxADW1skQbLXtVdBbxbwXeVsEm2h20\n\tW5nVef+jcMVxmD5IM0tpjnyyTuX+mKwiHNAakG6e2SaZsEJa0tLL0nywz2aypx2w6XzS\n\t7iWfFUWAaS9+Zjd6jM3G9Ot4deRs49grDju/PWri4gekMWL5KlnEsIn3JZKnohHVqmB+\n\tETeBgezZ1jTi00udNOWM2RylGPbsdS/l9MVlJvPSXKqytPeu02QmiOiw+zH0ycAxxq8p\n\tp26/iqK5qsFujSpmSmCmX4ntu40t8PmXVxMO1L36rRxVFhnS5e4aYNg0GM0Bq0nBMWv/\n\tNqkQ==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to\n\t:references;\n\tbh=/DRYr3B/EYZ677PMfEaLYMwAChuX2oMu0c9/fIaCpkc=;\n\tb=qYXiHtZIfyLAFJjd9WIy5iURxzbWTErEg21XQTBretoG57v4Hs7oBSwHRMOjtvm0RX\n\tlMge8cWUNZgIHRwKewQcVSataQC+Gem8xe7NDarH9xUqYWDUwaUXr84tGIoJdhO94AUw\n\t3qiWDoxLEW0au8eFNahlPi1dmrahSeX4Duaw0n+qv8G7EISdxbrNEVRpo2V+horzQDDQ\n\tFajcMxRBJS27NeVgnAyKyts424wG7Klx61v8nJRC68/W/cfsYeqzNx+4+5b/UzcbSKit\n\tarik10G6Y+76Qa8+/4DVLM+OT1MdvLcJJZqw5LJHyo5AuUuylkSTYDYOxxIF6j/pFTY9\n\tmU0Q==","X-Gm-Message-State":"AHPjjUgbiOmuOgagrQJX7l/HcUOCIIBGnc33SIBmYCgmQw7gDOGurTMo\n\t8eY24dbytIQeXMki8dCW8hqvjQ==","X-Google-Smtp-Source":"AOwi7QDleHmokhwdGW2YNVDxY83PS74+RVGw+d/xBq4mSu/ObuXdHVjpYSzL8eMRg6p6xGAG9f10WA==","X-Received":"by 10.159.244.24 with SMTP id x24mr219471plr.434.1505863637069; \n\tTue, 19 Sep 2017 16:27:17 -0700 (PDT)","From":"Eric Dumazet ","To":"\"David S . Miller\" ","Cc":"netdev ,\n\t\"Eric W . Biederman\" ,\n\tEric Dumazet , Eric Dumazet ","Subject":"[PATCH v2 net-next 2/7] kobject: copy env blob in one go","Date":"Tue, 19 Sep 2017 16:27:04 -0700","Message-Id":"<20170919232709.14690-3-edumazet@google.com>","X-Mailer":"git-send-email 2.14.1.690.gbb1197296e-goog","In-Reply-To":"<20170919232709.14690-1-edumazet@google.com>","References":"<20170919232709.14690-1-edumazet@google.com>","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"},"content":"No need to iterate over strings, just copy in one efficient memcpy() call.\n\nTested:\ntime perf record \"(for f in `seq 1 3000` ; do ip netns add tast$f; done)\"\n[ perf record: Woken up 10 times to write data ]\n[ perf record: Captured and wrote 8.224 MB perf.data (~359301 samples) ]\n\nreal 0m52.554s # instead of 1m7.492s\nuser 0m0.309s\nsys 0m51.375s # instead of 1m6.875s\n\n 9.88% ip [kernel.kallsyms] [k] netlink_broadcast_filtered\n 8.86% ip [kernel.kallsyms] [k] string\n 7.37% ip [kernel.kallsyms] [k] __ip6addrlbl_add\n 5.68% ip [kernel.kallsyms] [k] netlink_has_listeners\n 5.52% ip [kernel.kallsyms] [k] memcpy_erms\n 4.76% ip [kernel.kallsyms] [k] __alloc_skb\n 4.54% ip [kernel.kallsyms] [k] vsnprintf\n 3.94% ip [kernel.kallsyms] [k] format_decode\n 3.80% ip [kernel.kallsyms] [k] kmem_cache_alloc_node_trace\n 3.71% ip [kernel.kallsyms] [k] kmem_cache_alloc_node\n 3.66% ip [kernel.kallsyms] [k] kobject_uevent_env\n 3.38% ip [kernel.kallsyms] [k] strlen\n 2.65% ip [kernel.kallsyms] [k] _raw_spin_lock_irqsave\n 2.20% ip [kernel.kallsyms] [k] kfree\n 2.09% ip [kernel.kallsyms] [k] memset_erms\n 2.07% ip [kernel.kallsyms] [k] ___cache_free\n 1.95% ip [kernel.kallsyms] [k] kmem_cache_free\n 1.91% ip [kernel.kallsyms] [k] _raw_read_lock\n 1.45% ip [kernel.kallsyms] [k] ksize\n 1.25% ip [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore\n 1.00% ip [kernel.kallsyms] [k] widen_string\n\nSigned-off-by: Eric Dumazet \n---\n lib/kobject_uevent.c | 8 +-------\n 1 file changed, 1 insertion(+), 7 deletions(-)","diff":"diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c\nindex 4f48cc3b11d566e44c4115cc7716bc3b1cdf96df..78b2a7e378c0deda3b32b1178d7f44203702c3f2 100644\n--- a/lib/kobject_uevent.c\n+++ b/lib/kobject_uevent.c\n@@ -317,18 +317,12 @@ static int kobject_uevent_net_broadcast(struct kobject *kobj,\n \t\tskb = alloc_skb(len + env->buflen, GFP_KERNEL);\n \t\tif (skb) {\n \t\t\tchar *scratch;\n-\t\t\tint i;\n \n \t\t\t/* add header */\n \t\t\tscratch = skb_put(skb, len);\n \t\t\tsprintf(scratch, \"%s@%s\", action_string, devpath);\n \n-\t\t\t/* copy keys to our continuous event payload buffer */\n-\t\t\tfor (i = 0; i < env->envp_idx; i++) {\n-\t\t\t\tlen = strlen(env->envp[i]) + 1;\n-\t\t\t\tscratch = skb_put(skb, len);\n-\t\t\t\tstrcpy(scratch, env->envp[i]);\n-\t\t\t}\n+\t\t\tskb_put_data(skb, env->buf, env->buflen);\n \n \t\t\tNETLINK_CB(skb).dst_group = 1;\n \t\t\tretval = netlink_broadcast_filtered(uevent_sock, skb,\n","prefixes":["v2","net-next","2/7"]}