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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 A5AE7C433E6 for ; Mon, 31 Aug 2020 03:11:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88E1E20720 for ; Mon, 31 Aug 2020 03:11:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727941AbgHaDLf (ORCPT ); Sun, 30 Aug 2020 23:11:35 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:38760 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726712AbgHaDLK (ORCPT ); Sun, 30 Aug 2020 23:11:10 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R311e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07425;MF=richard.weiyang@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0U7J4KfP_1598843467; Received: from localhost(mailfrom:richard.weiyang@linux.alibaba.com fp:SMTPD_---0U7J4KfP_1598843467) by smtp.aliyun-inc.com(127.0.0.1); Mon, 31 Aug 2020 11:11:07 +0800 From: Wei Yang To: rostedt@goodmis.org, mingo@redhat.com Cc: linux-kernel@vger.kernel.org, Wei Yang Subject: [PATCH 2/6] ftrace: use fls() to get the bits for dup_hash() Date: Mon, 31 Aug 2020 11:11:00 +0800 Message-Id: <20200831031104.23322-3-richard.weiyang@linux.alibaba.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20200831031104.23322-1-richard.weiyang@linux.alibaba.com> References: <20200831031104.23322-1-richard.weiyang@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The effect here is to get the number of bits, lets use fls() to do this job. Signed-off-by: Wei Yang --- kernel/trace/ftrace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 12cb535769bc..9021e16fa079 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1370,8 +1370,9 @@ static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) /* * Make the hash size about 1/2 the # found */ - for (size /= 2; size; size >>= 1) - bits++; + bits = fls(size); + if (bits) + bits--; /* Don't allocate too much */ if (bits > FTRACE_HASH_MAX_BITS) -- 2.20.1 (Apple Git-117)