From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753854AbZI2Svb (ORCPT ); Tue, 29 Sep 2009 14:51:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753691AbZI2Sva (ORCPT ); Tue, 29 Sep 2009 14:51:30 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:40432 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753313AbZI2Sv3 (ORCPT ); Tue, 29 Sep 2009 14:51:29 -0400 Date: Tue, 29 Sep 2009 13:51:26 -0500 From: "Serge E. Hallyn" To: "Nikita V. Youshchenko" Cc: Oren Laadan , Andrew Morton , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Ingo Molnar , Pavel Emelyanov , Dan Smith , Oren Laadan Subject: Re: [PATCH v18 49/80] c/r: support for UTS namespace Message-ID: <20090929185126.GB13297@us.ibm.com> References: <1253749920-18673-1-git-send-email-orenl@librato.com> <1253749920-18673-50-git-send-email-orenl@librato.com> <200909292213.21266@blacky.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200909292213.21266@blacky.localdomain> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Nikita V. Youshchenko (yoush@cs.msu.su): > > +static struct uts_namespace *do_restore_uts_ns(struct ckpt_ctx *ctx) > > ... > > +#ifdef CONFIG_UTS_NS > > + uts_ns = create_uts_ns(); > > + if (!uts_ns) { > > + uts_ns = ERR_PTR(-ENOMEM); > > + goto out; > > + } > > + down_read(&uts_sem); > > + name = &uts_ns->name; > > + memcpy(name->sysname, h->sysname, sizeof(name->sysname)); > > + memcpy(name->nodename, h->nodename, sizeof(name->nodename)); > > + memcpy(name->release, h->release, sizeof(name->release)); > > + memcpy(name->version, h->version, sizeof(name->version)); > > + memcpy(name->machine, h->machine, sizeof(name->machine)); > > + memcpy(name->domainname, h->domainname, sizeof(name->domainname)); > > + up_read(&uts_sem); > > Could you please explain what for is this down_read() / up_read() ? > You operate only on local objects: 'name' points to just-created > uts_ns, 'h' is also local data. Yup, good point, that looks unnecessary. thanks, -serge From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCH v18 49/80] c/r: support for UTS namespace Date: Tue, 29 Sep 2009 13:51:26 -0500 Message-ID: <20090929185126.GB13297@us.ibm.com> References: <1253749920-18673-1-git-send-email-orenl@librato.com> <1253749920-18673-50-git-send-email-orenl@librato.com> <200909292213.21266@blacky.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200909292213.21266-vlktAfmDCSZSq9BJjBFyUp/QNRX+jHPU@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Nikita V. Youshchenko" Cc: Oren Laadan , Andrew Morton , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ingo Molnar , Pavel Emelyanov , Dan Smith , Oren Laadan List-Id: linux-api@vger.kernel.org Quoting Nikita V. Youshchenko (yoush-/llMDZXAvAOHXe+LvDLADg@public.gmane.org): > > +static struct uts_namespace *do_restore_uts_ns(struct ckpt_ctx *ctx) > > ... > > +#ifdef CONFIG_UTS_NS > > + uts_ns = create_uts_ns(); > > + if (!uts_ns) { > > + uts_ns = ERR_PTR(-ENOMEM); > > + goto out; > > + } > > + down_read(&uts_sem); > > + name = &uts_ns->name; > > + memcpy(name->sysname, h->sysname, sizeof(name->sysname)); > > + memcpy(name->nodename, h->nodename, sizeof(name->nodename)); > > + memcpy(name->release, h->release, sizeof(name->release)); > > + memcpy(name->version, h->version, sizeof(name->version)); > > + memcpy(name->machine, h->machine, sizeof(name->machine)); > > + memcpy(name->domainname, h->domainname, sizeof(name->domainname)); > > + up_read(&uts_sem); > > Could you please explain what for is this down_read() / up_read() ? > You operate only on local objects: 'name' points to just-created > uts_ns, 'h' is also local data. Yup, good point, that looks unnecessary. thanks, -serge -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id AB24A6B005A for ; Tue, 29 Sep 2009 14:48:08 -0400 (EDT) Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by e2.ny.us.ibm.com (8.14.3/8.13.1) with ESMTP id n8TIicrO002275 for ; Tue, 29 Sep 2009 14:44:38 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n8TIpRkx1839170 for ; Tue, 29 Sep 2009 14:51:27 -0400 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n8TIpQm9024235 for ; Tue, 29 Sep 2009 12:51:26 -0600 Date: Tue, 29 Sep 2009 13:51:26 -0500 From: "Serge E. Hallyn" Subject: Re: [PATCH v18 49/80] c/r: support for UTS namespace Message-ID: <20090929185126.GB13297@us.ibm.com> References: <1253749920-18673-1-git-send-email-orenl@librato.com> <1253749920-18673-50-git-send-email-orenl@librato.com> <200909292213.21266@blacky.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200909292213.21266@blacky.localdomain> Sender: owner-linux-mm@kvack.org To: "Nikita V. Youshchenko" Cc: Oren Laadan , Andrew Morton , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Ingo Molnar , Pavel Emelyanov , Dan Smith , Oren Laadan List-ID: Quoting Nikita V. Youshchenko (yoush@cs.msu.su): > > +static struct uts_namespace *do_restore_uts_ns(struct ckpt_ctx *ctx) > > ... > > +#ifdef CONFIG_UTS_NS > > + uts_ns = create_uts_ns(); > > + if (!uts_ns) { > > + uts_ns = ERR_PTR(-ENOMEM); > > + goto out; > > + } > > + down_read(&uts_sem); > > + name = &uts_ns->name; > > + memcpy(name->sysname, h->sysname, sizeof(name->sysname)); > > + memcpy(name->nodename, h->nodename, sizeof(name->nodename)); > > + memcpy(name->release, h->release, sizeof(name->release)); > > + memcpy(name->version, h->version, sizeof(name->version)); > > + memcpy(name->machine, h->machine, sizeof(name->machine)); > > + memcpy(name->domainname, h->domainname, sizeof(name->domainname)); > > + up_read(&uts_sem); > > Could you please explain what for is this down_read() / up_read() ? > You operate only on local objects: 'name' points to just-created > uts_ns, 'h' is also local data. Yup, good point, that looks unnecessary. thanks, -serge -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org