From xen-ia64-devel-bounces@lists.xensource.com Fri Nov 25 01:53:18 2011 Return-path: Envelope-to: archives@lists.xen.org Delivery-date: Fri, 25 Nov 2011 01:53:18 +0000 Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1RTkyX-0005pB-84; Fri, 25 Nov 2011 01:53:13 +0000 Received: from mail174.messagelabs.com ([85.158.138.51]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1RTkyV-0005ow-6D; Fri, 25 Nov 2011 01:53:11 +0000 X-Env-Sender: kuwa@jp.fujitsu.com X-Msg-Ref: server-10.tower-174.messagelabs.com!1322185956!2941608!1 X-Originating-IP: [192.51.44.36] X-StarScan-Version: 6.4.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 29250 invoked from network); 25 Nov 2011 01:52:38 -0000 Received: from fgwmail6.fujitsu.co.jp (HELO fgwmail6.fujitsu.co.jp) (192.51.44.36) by server-10.tower-174.messagelabs.com with DHE-RSA-AES256-SHA encrypted SMTP; 25 Nov 2011 01:52:38 -0000 Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id CCD8F3EE0AE; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id B5A2D45DEEB; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id A06F545DED9; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 93ED41DB8038; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from flabmail.flab.fujitsu.co.jp (flabmail.flab.fujitsu.co.jp [10.25.192.37]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 62B4C1DB803C; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from vskawa.flab.fujitsu.co.jp (vskawa.flab.fujitsu.co.jp [10.25.192.39]) by flabmail.flab.fujitsu.co.jp (8.14.4/8.14.4/110310-Fujitsu Labs. Domain Mail Master) with ESMTP id pAP1pkAR023210; Fri, 25 Nov 2011 10:52:34 +0900 (JST) X-AuditID: 0a19c027-b7ca5ae000001565-39-4ecef4e20854 Received: from dm.kawasaki.flab.fujitsu.co.jp (dm.kawasaki.flab.fujitsu.co.jp [10.25.192.105]) by vskawa.flab.fujitsu.co.jp (Symantec Brightmail Gateway) with SMTP id F9.39.05477.2E4FECE4; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from eve.cad.flab.fujitsu.co.jp (eve.cad.flab.fujitsu.co.jp [10.25.228.68]) by dm.kawasaki.flab.fujitsu.co.jp (8.14.4/8.14.4/110311-Fujitsu Labs. Kawasaki Domain Mail Master) with ESMTP id pAP1qYQQ024714; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from localhost (localhost [127.0.0.1]) by eve.cad.flab.fujitsu.co.jp (8.14.4/8.14.4) with ESMTP id pAP1qX6F013664; Fri, 25 Nov 2011 10:52:33 +0900 (JST) (envelope-from kuwa@jp.fujitsu.com) Date: Fri, 25 Nov 2011 10:52:13 +0900 (JST) Message-Id: <20111125.105213.310075014.kuwa@jp.fujitsu.com> To: JBeulich@suse.com From: "KUWAMURA Shin'ya" In-Reply-To: <4EBD56C50200007800060781@nat28.tlf.novell.com> References: <4EBD56C50200007800060781@nat28.tlf.novell.com> X-Mailer: Mew version 6.4 on Emacs 23.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 X-Brightmail-Tracker: AAAAAQAAAZE= Cc: xen-devel@lists.xensource.com, xen-ia64-devel@lists.xensource.com Subject: Re: [Xen-ia64-devel] [Xen-devel] [PATCH] ia64: introduce atomic_{read, write}NN() X-BeenThere: xen-ia64-devel@lists.xensource.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of the ia64 port of Xen List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xen-ia64-devel-bounces@lists.xensource.com Errors-To: xen-ia64-devel-bounces@lists.xensource.com Hi Jan, Excuse me for too late response. Thank you for your work. But I have a question. >>>>> On Fri, 11 Nov 2011 16:09:25 +0000 >>>>> JBeulich@suse.com("Jan Beulich") said: > > +#define build_atomic_read(tag, type) \ > +static inline type atomic_read##tag(const volatile type *addr) \ > +{ \ > + type ret; \ > + asm volatile("ld%2.acq %0 = %1" \ > + : "=r" (ret) \ > + : "m" (*addr), "i" (sizeof(type))); \ > + return ret; \ > +} > + > +#define build_atomic_write(tag, type) \ > +static inline void atomic_write##tag(volatile type *addr, type val) \ > +{ \ > + asm volatile("st%2.rel %0 = %1" \ > + : "=m" (*addr) \ > + : "r" (val), "i" (sizeof(type))); \ > +} Why do you use explicitly ld.acq and st.rel? I think that volatile variables are always accessed using ld.acq and st.rel and they are not required. For example, The implementation of Linux is as follows: #define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic64_read(v) (*(volatile long *)&(v)->counter) Best regards, -- KUWAMURA Shin'ya _______________________________________________ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel From xen-ia64-devel-bounces@lists.xensource.com Fri Nov 25 01:53:18 2011 Return-path: Envelope-to: archives@lists.xen.org Delivery-date: Fri, 25 Nov 2011 01:53:18 +0000 Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1RTkyX-0005pB-84; Fri, 25 Nov 2011 01:53:13 +0000 Received: from mail174.messagelabs.com ([85.158.138.51]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1RTkyV-0005ow-6D; Fri, 25 Nov 2011 01:53:11 +0000 X-Env-Sender: kuwa@jp.fujitsu.com X-Msg-Ref: server-10.tower-174.messagelabs.com!1322185956!2941608!1 X-Originating-IP: [192.51.44.36] X-StarScan-Version: 6.4.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 29250 invoked from network); 25 Nov 2011 01:52:38 -0000 Received: from fgwmail6.fujitsu.co.jp (HELO fgwmail6.fujitsu.co.jp) (192.51.44.36) by server-10.tower-174.messagelabs.com with DHE-RSA-AES256-SHA encrypted SMTP; 25 Nov 2011 01:52:38 -0000 Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id CCD8F3EE0AE; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id B5A2D45DEEB; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id A06F545DED9; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 93ED41DB8038; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from flabmail.flab.fujitsu.co.jp (flabmail.flab.fujitsu.co.jp [10.25.192.37]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 62B4C1DB803C; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from vskawa.flab.fujitsu.co.jp (vskawa.flab.fujitsu.co.jp [10.25.192.39]) by flabmail.flab.fujitsu.co.jp (8.14.4/8.14.4/110310-Fujitsu Labs. Domain Mail Master) with ESMTP id pAP1pkAR023210; Fri, 25 Nov 2011 10:52:34 +0900 (JST) X-AuditID: 0a19c027-b7ca5ae000001565-39-4ecef4e20854 Received: from dm.kawasaki.flab.fujitsu.co.jp (dm.kawasaki.flab.fujitsu.co.jp [10.25.192.105]) by vskawa.flab.fujitsu.co.jp (Symantec Brightmail Gateway) with SMTP id F9.39.05477.2E4FECE4; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from eve.cad.flab.fujitsu.co.jp (eve.cad.flab.fujitsu.co.jp [10.25.228.68]) by dm.kawasaki.flab.fujitsu.co.jp (8.14.4/8.14.4/110311-Fujitsu Labs. Kawasaki Domain Mail Master) with ESMTP id pAP1qYQQ024714; Fri, 25 Nov 2011 10:52:34 +0900 (JST) Received: from localhost (localhost [127.0.0.1]) by eve.cad.flab.fujitsu.co.jp (8.14.4/8.14.4) with ESMTP id pAP1qX6F013664; Fri, 25 Nov 2011 10:52:33 +0900 (JST) (envelope-from kuwa@jp.fujitsu.com) Date: Fri, 25 Nov 2011 10:52:13 +0900 (JST) Message-Id: <20111125.105213.310075014.kuwa@jp.fujitsu.com> To: JBeulich@suse.com From: "KUWAMURA Shin'ya" In-Reply-To: <4EBD56C50200007800060781@nat28.tlf.novell.com> References: <4EBD56C50200007800060781@nat28.tlf.novell.com> X-Mailer: Mew version 6.4 on Emacs 23.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 X-Brightmail-Tracker: AAAAAQAAAZE= Cc: xen-devel@lists.xensource.com, xen-ia64-devel@lists.xensource.com Subject: Re: [Xen-ia64-devel] [Xen-devel] [PATCH] ia64: introduce atomic_{read, write}NN() X-BeenThere: xen-ia64-devel@lists.xensource.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of the ia64 port of Xen List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xen-ia64-devel-bounces@lists.xensource.com Errors-To: xen-ia64-devel-bounces@lists.xensource.com Hi Jan, Excuse me for too late response. Thank you for your work. But I have a question. >>>>> On Fri, 11 Nov 2011 16:09:25 +0000 >>>>> JBeulich@suse.com("Jan Beulich") said: > > +#define build_atomic_read(tag, type) \ > +static inline type atomic_read##tag(const volatile type *addr) \ > +{ \ > + type ret; \ > + asm volatile("ld%2.acq %0 = %1" \ > + : "=r" (ret) \ > + : "m" (*addr), "i" (sizeof(type))); \ > + return ret; \ > +} > + > +#define build_atomic_write(tag, type) \ > +static inline void atomic_write##tag(volatile type *addr, type val) \ > +{ \ > + asm volatile("st%2.rel %0 = %1" \ > + : "=m" (*addr) \ > + : "r" (val), "i" (sizeof(type))); \ > +} Why do you use explicitly ld.acq and st.rel? I think that volatile variables are always accessed using ld.acq and st.rel and they are not required. For example, The implementation of Linux is as follows: #define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic64_read(v) (*(volatile long *)&(v)->counter) Best regards, -- KUWAMURA Shin'ya _______________________________________________ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel