From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from [222.73.24.84] (helo=song.cn.fujitsu.com) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1UAGFS-00005L-AV for kexec@lists.infradead.org; Tue, 26 Feb 2013 08:50:55 +0000 Message-ID: <512C76FE.4070109@cn.fujitsu.com> Date: Tue, 26 Feb 2013 16:49:02 +0800 From: Zhang Yanfei MIME-Version: 1.0 Subject: Re: [PATCH v3 2/2] kexec: Use min_t to simplify logic References: <512C44E4.70907@cn.fujitsu.com> <512C4881.90409@cn.fujitsu.com> <1361867881.2023.16.camel@joe-AO722> In-Reply-To: <1361867881.2023.16.camel@joe-AO722> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Joe Perches Cc: Andrew Morton , Simon Horman , "kexec@lists.infradead.org" , "Eric W. Biederman" , "linux-kernel@vger.kernel.org" 5LqOIDIwMTPlubQwMuaciDI25pelIDE2OjM4LCBKb2UgUGVyY2hlcyDlhpnpgZM6Cj4gT24gVHVl LCAyMDEzLTAyLTI2IGF0IDEzOjMwICswODAwLCBaaGFuZyBZYW5mZWkgd3JvdGU6Cj4+IFRoaXMg aXMganVzdCBhIHR3ZWFrOiB1c2luZyBtaW5fdCB0byBzaW1wbGlmeSBsb2dpYyBvZiB2YXJpYWJs ZQo+PiBhc3NpZ25tZW50cy4KPj4KPj4gdjM6Cj4+IC0gY2FzdCB0eXBlIG9mIChQQUdFX1NJWkUg LSAobWFkZHIgJiB+UEFHRV9NQVNLKSkgaW50byBzaXplX3QuCj4gCj4gV2h5PyAgSXNuJ3QgdGhp cyBqdXN0IGEgcmVkdW5kYW50IGNhc3Q/Cj4gCj4+IGRpZmYgLS1naXQgYS9rZXJuZWwva2V4ZWMu YyBiL2tlcm5lbC9rZXhlYy5jCj4gW10KPj4gQEAgLTgyMiwxMyArODIyLDkgQEAgc3RhdGljIGlu dCBraW1hZ2VfbG9hZF9ub3JtYWxfc2VnbWVudChzdHJ1Y3Qga2ltYWdlICppbWFnZSwKPiBbXQo+ PiArCQltY2h1bmsgPSBtaW5fdChzaXplX3QsIG1ieXRlcywKPj4gKwkJCSAgICAgICAoc2l6ZV90 KShQQUdFX1NJWkUgLSAobWFkZHIgJiB+UEFHRV9NQVNLKSkpOwo+IAo+ICNkZWZpbmUgbWluX3Qo dHlwZSwgeCwgeSkgKHsJCQlcCj4gCXR5cGUgX19taW4xID0gKHgpOwkJCVwKPiAJdHlwZSBfX21p bjIgPSAoeSk7CQkJXAo+IAlfX21pbjEgPCBfX21pbjIgPyBfX21pbjE6IF9fbWluMjsgfSkKPiAK PiAKPiAKCkhtbSwgZnJvbSB0aGUgZGVmaW5pdGlvbiwgdGhlIGNhc3QgaXMgcmVkdW5kYW50LgoK TWF5YmUgSSBtaXN1bmRlcnN0b29kIHdoYXQgQW5kcmV3IG1lYW50IGluIHRoZSBtYWlsIHJlbGF0 ZWQgdG8gdjI6CgoiVGhlIHR5cGVzIG9mIFBBR0VfU0laRSBhbmQgUEFHRV9NQVNLIGFyZSB2YWd1 ZSAtIGlpcmMgdGhleSBvbmNlIGhhZApkaWZmZXJlbnQgdHlwZXMgb24gZGlmZmVyZW50IGFyY2hp dGVjdHVyZXMsIHNvIHNvbWUgZm9ybSBvZiBjYXN0aW5nIGlzCnVuYXZvaWRhYmxlIGhlcmUuIgoK QW5kcmV3LCBjb3VsZCB5b3UgcGxlYXNlIGV4cGxhaW4gdGhlIGNhc3RpbmcgeW91IG1lYW50IGFi b3ZlPwoKVGhhbmtzClpoYW5nCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fXwprZXhlYyBtYWlsaW5nIGxpc3QKa2V4ZWNAbGlzdHMuaW5mcmFkZWFkLm9yZwpo dHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2tleGVjCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759787Ab3BZIuv (ORCPT ); Tue, 26 Feb 2013 03:50:51 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:11532 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1759746Ab3BZIus convert rfc822-to-8bit (ORCPT ); Tue, 26 Feb 2013 03:50:48 -0500 X-IronPort-AV: E=Sophos;i="4.84,739,1355068800"; d="scan'208";a="6771481" Message-ID: <512C76FE.4070109@cn.fujitsu.com> Date: Tue, 26 Feb 2013 16:49:02 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.8) Gecko/20121012 Thunderbird/10.0.8 MIME-Version: 1.0 To: Joe Perches CC: Andrew Morton , "Eric W. Biederman" , Simon Horman , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3 2/2] kexec: Use min_t to simplify logic References: <512C44E4.70907@cn.fujitsu.com> <512C4881.90409@cn.fujitsu.com> <1361867881.2023.16.camel@joe-AO722> In-Reply-To: <1361867881.2023.16.camel@joe-AO722> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/02/26 16:49:53, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/02/26 16:49:56 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 于 2013年02月26日 16:38, Joe Perches 写道: > On Tue, 2013-02-26 at 13:30 +0800, Zhang Yanfei wrote: >> This is just a tweak: using min_t to simplify logic of variable >> assignments. >> >> v3: >> - cast type of (PAGE_SIZE - (maddr & ~PAGE_MASK)) into size_t. > > Why? Isn't this just a redundant cast? > >> diff --git a/kernel/kexec.c b/kernel/kexec.c > [] >> @@ -822,13 +822,9 @@ static int kimage_load_normal_segment(struct kimage *image, > [] >> + mchunk = min_t(size_t, mbytes, >> + (size_t)(PAGE_SIZE - (maddr & ~PAGE_MASK))); > > #define min_t(type, x, y) ({ \ > type __min1 = (x); \ > type __min2 = (y); \ > __min1 < __min2 ? __min1: __min2; }) > > > Hmm, from the definition, the cast is redundant. Maybe I misunderstood what Andrew meant in the mail related to v2: "The types of PAGE_SIZE and PAGE_MASK are vague - iirc they once had different types on different architectures, so some form of casting is unavoidable here." Andrew, could you please explain the casting you meant above? Thanks Zhang