From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3EF2C433B4 for ; Sun, 16 May 2021 23:45:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 65BFB61166 for ; Sun, 16 May 2021 23:45:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65BFB61166 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 813456B0036; Sun, 16 May 2021 19:45:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7C3AE6B006E; Sun, 16 May 2021 19:45:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 63D2E6B0070; Sun, 16 May 2021 19:45:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 327966B0036 for ; Sun, 16 May 2021 19:45:21 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C1B40180AD817 for ; Sun, 16 May 2021 23:45:20 +0000 (UTC) X-FDA: 78148728000.23.7DBC948 Received: from mail-lf1-f41.google.com (mail-lf1-f41.google.com [209.85.167.41]) by imf11.hostedemail.com (Postfix) with ESMTP id 681B52000243 for ; Sun, 16 May 2021 23:45:18 +0000 (UTC) Received: by mail-lf1-f41.google.com with SMTP id i22so6074378lfl.10 for ; Sun, 16 May 2021 16:45:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zg7hQi4e0dmMw67bNaK0NhSpXsVNqynwe8FbhANAgyE=; b=NTGxUEbWNI9aFZC1eBJ+m8ZlVUpibiJe9a9Ua7uK226aH5bpHAzZRAOPIWzmggYSfh DVkADuIZsb7wfUz8niQDEYRKrUvrb+MK6aWxofyuU2LGJ8ZaqsfRQK6saBBLpcDFI7Tc 331Abnoo14KwylIrLCa0n7OOWdopS9VGZhyuLYuIcMxLkXphcJZ/adeJFyTmQZJ5M+gH 1HsEYzkz59ha5Hwmlun30Gpdh7NTxQbIa6KYbCDpCBVFWq0m6SUQVQDn9aDD2qfiFyyR ogdeaTDW9oOTE0Raj/L+JPVIyfLC2VZ8oNIxU0bDzdAC85tupFUiTmxd0GqycVKY7nW3 ztAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zg7hQi4e0dmMw67bNaK0NhSpXsVNqynwe8FbhANAgyE=; b=Bymx3ZOGzNN6iLRxNuosUi1ufnl5o2/xMfLuys37han4CjyqBkdGAOvUfs6Izg+PWK jsni2jvA3IXLlLFsmmkpyK+n+cYKbIT/K/ZdS1zxjLBwCusGX/Gqqnz5ikgwha5nXc/Q 04RcmDPjUZIWkQAJM4b74HBv0idtuCZNnsFLKNv4KUAm2UX9XhsB7dnlKp8uGfyx8ig0 MrGSAqWlW/aukoyBnaINXps4OJIfF6bNc4Hpv4Z/QV5TGSO/yNWmPqU5SGrP23NOqekQ ryLqyw0ST3cH3RHnw2UUs4eavo0MkzyOuV1vb/k+S8TPz2Jpesj02GigXggev50W3Ft8 MI5A== X-Gm-Message-State: AOAM5329avVv2OkWCQv2wy4AIYyy+ieNVKrI5/MrQ2chkIlP0kgzaLH7 /dEeF5JQw4/2j8JjcrlLqDpG+IYNlQ5DAbSQcqA= X-Google-Smtp-Source: ABdhPJy44b/9XGxD5SVS9/3cqPNzdb1OHTk8jgqk239PYt2BFtdT6ZlU0xcpvsCF5wK9pEMlt7CoeSLoNczNdhQy/XY= X-Received: by 2002:ac2:5a4f:: with SMTP id r15mr579079lfn.619.1621208718915; Sun, 16 May 2021 16:45:18 -0700 (PDT) MIME-Version: 1.0 References: <20210515180817.1751084-1-trix@redhat.com> In-Reply-To: <20210515180817.1751084-1-trix@redhat.com> From: Wonhyuk Yang Date: Mon, 17 May 2021 08:45:09 +0900 Message-ID: Subject: Re: [PATCH] percpu: initialize best_upa variable To: trix@redhat.com Cc: Dennis Zhou , Tejun Heo , Christoph Lameter , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 681B52000243 Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=NTGxUEbW; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf11.hostedemail.com: domain of vvghjk1234@gmail.com designates 209.85.167.41 as permitted sender) smtp.mailfrom=vvghjk1234@gmail.com X-Rspamd-Server: rspam03 X-Stat-Signature: zezz9ian94sba1wdscgde9pkbrphkfkn X-HE-Tag: 1621208718-420565 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, May 16, 2021 at 3:08 AM wrote: > Static analysis reports this problem > percpu.c:2945:6: warning: Assigned value is garbage or undefined > upa = best_upa; > ^ ~~~~~~~~ > best_upa may not be set, so initialize it. Hi, Actually, best_upa is always set in the for loop below. when upa is 1, It will always satisfy all conditions. > diff --git a/mm/percpu.c b/mm/percpu.c > index a257c3efdf18b..6578b706fae81 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -2916,6 +2916,7 @@ static struct pcpu_alloc_info * __init __flatten pcpu_build_alloc_info( > * Related to atom_size, which could be much larger than the unit_size. > */ > last_allocs = INT_MAX; > + best_upa = max_upa; > for (upa = max_upa; upa; upa--) { > int allocs = 0, wasted = 0; It doesn't seem to be a problem. But, how about this? best_upa = 1; for (upa = max_upa; upa>1; upa--)