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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 27EA4C3A59E for ; Thu, 22 Aug 2019 01:51:20 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 F20D320673 for ; Thu, 22 Aug 2019 01:51:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="hiJU/Pgg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F20D320673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=e3eZctHzytxYkwXmDhtITWFD8JiNjv5YcSq/tBQsOws=; b=hiJU/PggCJi4Mo SUUQmgsNtPRVVmjEPpIsvKWVnLk5qrTAIGlqlNSCEbvthMv+muQILc9e8+sTJQZiOQly4P7/FhPlX E44WfG+tH8hLtVZmAz02A5F62mBTt0NL6Z5Uz+VLAMCsJCGly/dr/miDhtYF6Mivldy0Lf/xBakl1 IU3cPXIIr+4xpX5z84d7tcoZpRCY+E6GeeRARSCiIPAvZ9nD9RCOC1ZjK4353B3BWXh+1PIXjeXDh drPnVm6BTd4R7K0eEWUud3Px98+N1JSL53WiwsUmZok4u87Nqcy870tz0yaJK9TAeuhWMw/arRUPX WjSu2PKvPG2L5GHVwnvA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i0cFz-0002fk-2T; Thu, 22 Aug 2019 01:51:19 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i0cFw-0002fL-Al for linux-riscv@lists.infradead.org; Thu, 22 Aug 2019 01:51:17 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 9559C68BFE; Thu, 22 Aug 2019 03:51:13 +0200 (CEST) Date: Thu, 22 Aug 2019 03:51:13 +0200 From: Christoph Hellwig To: Atish Patra Subject: Re: [PATCH v3 3/3] RISC-V: Do not invoke SBI call if cpumask is empty Message-ID: <20190822015113.GC11922@lst.de> References: <20190822004644.25829-1-atish.patra@wdc.com> <20190822004644.25829-4-atish.patra@wdc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190822004644.25829-4-atish.patra@wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190821_185116_524243_D24AA561 X-CRM114-Status: GOOD ( 14.00 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Albert Ou , Palmer Dabbelt , linux-kernel@vger.kernel.org, Anup Patel , Andreas Schwab , Paul Walmsley , linux-riscv@lists.infradead.org, Christoph Hellwig Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org On Wed, Aug 21, 2019 at 05:46:44PM -0700, Atish Patra wrote: > SBI calls are expensive. If cpumask is empty, there is no need to > trap via SBI as no remote tlb flushing is required. > > Signed-off-by: Atish Patra > --- > arch/riscv/mm/tlbflush.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c > index 9f58b3790baa..2bd3c418d769 100644 > --- a/arch/riscv/mm/tlbflush.c > +++ b/arch/riscv/mm/tlbflush.c > @@ -21,6 +21,9 @@ static void __sbi_tlb_flush_range(struct cpumask *cmask, unsigned long start, > goto issue_sfence; > } > > + if (cpumask_empty(cmask)) > + goto done; I think this can even be done before the get_cpu to optimize it a little further. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 53F6AC3A59E for ; Thu, 22 Aug 2019 01:51:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F65B20673 for ; Thu, 22 Aug 2019 01:51:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730738AbfHVBvR (ORCPT ); Wed, 21 Aug 2019 21:51:17 -0400 Received: from verein.lst.de ([213.95.11.211]:42693 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730716AbfHVBvQ (ORCPT ); Wed, 21 Aug 2019 21:51:16 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 9559C68BFE; Thu, 22 Aug 2019 03:51:13 +0200 (CEST) Date: Thu, 22 Aug 2019 03:51:13 +0200 From: Christoph Hellwig To: Atish Patra Cc: linux-kernel@vger.kernel.org, Albert Ou , linux-riscv@lists.infradead.org, Palmer Dabbelt , Paul Walmsley , Christoph Hellwig , Anup Patel , Andreas Schwab Subject: Re: [PATCH v3 3/3] RISC-V: Do not invoke SBI call if cpumask is empty Message-ID: <20190822015113.GC11922@lst.de> References: <20190822004644.25829-1-atish.patra@wdc.com> <20190822004644.25829-4-atish.patra@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190822004644.25829-4-atish.patra@wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 21, 2019 at 05:46:44PM -0700, Atish Patra wrote: > SBI calls are expensive. If cpumask is empty, there is no need to > trap via SBI as no remote tlb flushing is required. > > Signed-off-by: Atish Patra > --- > arch/riscv/mm/tlbflush.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c > index 9f58b3790baa..2bd3c418d769 100644 > --- a/arch/riscv/mm/tlbflush.c > +++ b/arch/riscv/mm/tlbflush.c > @@ -21,6 +21,9 @@ static void __sbi_tlb_flush_range(struct cpumask *cmask, unsigned long start, > goto issue_sfence; > } > > + if (cpumask_empty(cmask)) > + goto done; I think this can even be done before the get_cpu to optimize it a little further.