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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,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 8CDF6C43331 for ; Sun, 29 Mar 2020 12:12:43 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1B63E2074A for ; Sun, 29 Mar 2020 12:12:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="QM0WJZ3P" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B63E2074A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=SDF.ORG Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 74B81166D; Sun, 29 Mar 2020 14:11:51 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 74B81166D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1585483961; bh=LmL8bvx1ci2dN6TTPz/hmLgN5t6w+ZTCgyIJdvgaqos=; h=Date:From:To:Subject:References:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=QM0WJZ3PQbHuYoryUHitEfRq9M0lVeOh6nz4aAMLAzTMa+ENLN2sC8ME6Wt5gVUKI zDcIktdFeZB5G1pK/XzTCdvMsaGaS/hPQaryBWc4GvLkFg2sgM5oNFRaW08DjQ/yuR IV4jfQtleWbzysT7fqqwOhillgyG9YgX2UfIgDzc= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id F1783F80140; Sun, 29 Mar 2020 14:11:50 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 8F637F80146; Sun, 29 Mar 2020 14:11:49 +0200 (CEST) Received: from mx.sdf.org (mx.sdf.org [205.166.94.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id BB0FDF8013F for ; Sun, 29 Mar 2020 14:11:43 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz BB0FDF8013F Received: from sdf.org (IDENT:lkml@sdf.lonestar.org [205.166.94.16]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 02TCBVww020963 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Sun, 29 Mar 2020 12:11:32 GMT Received: (from lkml@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 02TCBTk2014576; Sun, 29 Mar 2020 12:11:29 GMT Date: Sun, 29 Mar 2020 12:11:29 +0000 From: George Spelvin To: Takashi Iwai Subject: Re: [RFC PATCH v1 13/50] Avoid some useless msecs/jiffies conversions Message-ID: <20200329121129.GC11951@SDF.ORG> References: <202003281643.02SGhBrh000992@sdf.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Cc: lkml@sdf.org, alsa-devel@alsa-project.org, Marek Lindner , linux-scsi@vger.kernel.org, Simon Wunderlich , linux-wireless@vger.kernel.org, Takashi Iwai , Antonio Quartulli , linux-kernel@vger.kernel.org, b.a.t.m.a.n@diktynna.open-mesh.org, Hannes Reinecke , Johannes Berg , Sven Eckelmann X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Sun, Mar 29, 2020 at 09:52:23AM +0200, Takashi Iwai wrote: > On Thu, 22 Aug 2019 02:25:10 +0200, George Spelvin wrote: >> Likewise, "msecs_to_jiffies(seconds * 1000)" is more >> conveniently written "seconds * HZ". > > I thought the compiler already optimizes to the constant calculation > for the above case? It optimizes that if the entire argument, including "seconds", is a compile-time constant. However, given "msecs_to_jiffies(hdev->rpa_timeout * 1000);", the computatin is non-trivial. 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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 3BB54C43331 for ; Sun, 29 Mar 2020 12:16:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18A7C2073B for ; Sun, 29 Mar 2020 12:16:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728089AbgC2MQA (ORCPT ); Sun, 29 Mar 2020 08:16:00 -0400 Received: from mx.sdf.org ([205.166.94.20]:64164 "EHLO mx.sdf.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727901AbgC2MP7 (ORCPT ); Sun, 29 Mar 2020 08:15:59 -0400 Received: from sdf.org (IDENT:lkml@sdf.lonestar.org [205.166.94.16]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 02TCBVww020963 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Sun, 29 Mar 2020 12:11:32 GMT Received: (from lkml@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 02TCBTk2014576; Sun, 29 Mar 2020 12:11:29 GMT Date: Sun, 29 Mar 2020 12:11:29 +0000 From: George Spelvin To: Takashi Iwai Cc: linux-kernel@vger.kernel.org, Hannes Reinecke , linux-scsi@vger.kernel.org, Marek Lindner , Simon Wunderlich , Antonio Quartulli , Sven Eckelmann , b.a.t.m.a.n@diktynna.open-mesh.org, Johannes Berg , linux-wireless@vger.kernel.org, Jaroslav Kysela , Takashi Iwai , alsa-devel@alsa-project.org, lkml@sdf.org Subject: Re: [RFC PATCH v1 13/50] Avoid some useless msecs/jiffies conversions Message-ID: <20200329121129.GC11951@SDF.ORG> References: <202003281643.02SGhBrh000992@sdf.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On Sun, Mar 29, 2020 at 09:52:23AM +0200, Takashi Iwai wrote: > On Thu, 22 Aug 2019 02:25:10 +0200, George Spelvin wrote: >> Likewise, "msecs_to_jiffies(seconds * 1000)" is more >> conveniently written "seconds * HZ". > > I thought the compiler already optimizes to the constant calculation > for the above case? It optimizes that if the entire argument, including "seconds", is a compile-time constant. However, given "msecs_to_jiffies(hdev->rpa_timeout * 1000);", the computatin is non-trivial.