Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752502AbXIYIvi (ORCPT ); Tue, 25 Sep 2007 04:51:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751726AbXIYIv3 (ORCPT ); Tue, 25 Sep 2007 04:51:29 -0400 Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:50291 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059AbXIYIv1 (ORCPT ); Tue, 25 Sep 2007 04:51:27 -0400 Message-Id: <46F8CBD4.5000900@mxs.nes.nec.co.jp> Date: Tue, 25 Sep 2007 17:50:28 +0900 From: "Ken'ichi Ohmichi" User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Satyam Sharma CC: Andrew Morton , Adrian Bunk , kexec-ml , lkml , David Rientjes , Joe Perches Subject: Re: [PATCH 6/4] [-mm patch] use the existing offsetof(). References: <46E9F6A9.8060500@mxs.nes.nec.co.jp> <46E9F942.5070007@mxs.nes.nec.co.jp> <20070914190350.011cdadb.akpm@linux-foundation.org> <46F204FD.6040303@mxs.nes.nec.co.jp> <46F205DB.70209@mxs.nes.nec.co.jp> In-Reply-To: Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3360 Lines: 85 Hi Satyam, Satyam Sharma wrote: > > BTW I don't think these macros are such a big win in readability or > > code clarity anyway. And I noticed that there are still some open > > calls to vmcoreinfo_append_str() in kexec.c (such as for the OS_RELEASE > > case) which you haven't macro-ized ... we end up having code that looks > > like: > > > > vmcoreinfo_append_str(...); > > ... > > > > ... > > VMCOREINFO_OFFSET(...); > > ... > > > > and it's not even obvious (unless you follow on to the definition of the > > later macro) that the above two are *exactly* the same. So you could also > > consider just losing the macros altogether. I want to use these macros for calls to vmcoreinfo_append_str(), because the strings included in each macro ("SIZE(XXX)=", "OFFSET(XXX)=", etc.) are very important. makedumpfile command reads these strings and gets the debugging information (structure sizes, field offsets, etc.). If losing these macros and there is a typo like "OFESET(page.mapping)=", the command cannot run. To prevent this mistake, these macros are very useful. For more readability, I think it is good that all the calls are changed to macros having a prefix "VMCOREINFO_" like the attached patch. Thanks Ken'ichi Ohmichi --- Signed-off-by: Ken'ichi Ohmichi --- diff -rpuN a/include/linux/kexec.h b/include/linux/kexec.h --- a/include/linux/kexec.h 2007-09-21 09:28:23.000000000 +0900 +++ b/include/linux/kexec.h 2007-09-21 10:26:24.000000000 +0900 @@ -127,6 +127,10 @@ void vmcoreinfo_append_str(const char *f __attribute__ ((format (printf, 1, 2))); unsigned long paddr_vmcoreinfo_note(void); +#define VMCOREINFO_OSRELEASE(name) \ + vmcoreinfo_append_str("OSRELEASE=%s\n", #name) +#define VMCOREINFO_PAGESIZE(value) \ + vmcoreinfo_append_str("PAGESIZE=%ld\n", value) #define VMCOREINFO_SYMBOL(name) \ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) #define VMCOREINFO_SIZE(name) \ @@ -134,8 +138,8 @@ unsigned long paddr_vmcoreinfo_note(void #define VMCOREINFO_STRUCT_SIZE(name) \ vmcoreinfo_append_str("SIZE(%s)=%zu\n", #name, sizeof(struct name)) #define VMCOREINFO_OFFSET(name, field) \ - vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \ - (unsigned long)&(((struct name *)0)->field)) + vmcoreinfo_append_str("OFFSET(%s.%s)=%zu\n", #name, #field, \ + offsetof(struct name, field)) #define VMCOREINFO_LENGTH(name, value) \ vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value) #define VMCOREINFO_NUMBER(name) \ diff -rpuN a/kernel/kexec.c b/kernel/kexec.c --- a/kernel/kexec.c 2007-09-21 09:28:22.000000000 +0900 +++ b/kernel/kexec.c 2007-09-21 10:17:56.000000000 +0900 @@ -1195,8 +1195,8 @@ unsigned long __attribute__ ((weak)) pad static int __init crash_save_vmcoreinfo_init(void) { - vmcoreinfo_append_str("OSRELEASE=%s\n", init_uts_ns.name.release); - vmcoreinfo_append_str("PAGESIZE=%ld\n", PAGE_SIZE); + VMCOREINFO_OSRELEASE(init_uts_ns.name.release); + VMCOREINFO_PAGESIZE(PAGE_SIZE); VMCOREINFO_SYMBOL(init_uts_ns); VMCOREINFO_SYMBOL(node_online_map); _ - 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/