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=-17.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 52B19C433E6 for ; Mon, 8 Mar 2021 13:00:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10660651CC for ; Mon, 8 Mar 2021 13:00:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229793AbhCHNAN (ORCPT ); Mon, 8 Mar 2021 08:00:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:52510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229655AbhCHM7v (ORCPT ); Mon, 8 Mar 2021 07:59:51 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A40A364FB3; Mon, 8 Mar 2021 12:59:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615208391; bh=wxbL/Pa2LuwpiP3JjTmeepdQiCQNIv7MrwRtEg7zXKs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Axro0NZGoslIDIELA+vcrcmqfYkqa2Kispoq8GG1PhQ+GbLbBiVjYT8i8jgLKG4+t 0fv43dyqgy73NVWZvlxfP7NEXWO08+h2cNMWE5stsP7Xn2lITSc9qLMVnWFStmBVXE vs1r1s8hmLch1KCzGcG4ydisTj2Ge23kJtK8xl42cLMN2A8UiDNErKDw5DcZHIFbD6 9K8aQt38rkcpeItasZYjaZvhNVeGX18YxVC/VGGk2v8hRYu0rhxACMwLvrBvkRVoeZ F7aueLZ/eZ9SROhzZ4ZBToOl9R3Tct1GI87ov0yEXcXIT5M1xYVSUtTNMog3TwlzFj rbibwoRAigyVA== Date: Mon, 8 Mar 2021 12:59:46 +0000 From: Will Deacon To: Barry Song Cc: corbet@lwn.net, linux-doc@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxarm@openeuler.org, Mel Gorman , Andy Lutomirski , Catalin Marinas Subject: Re: [PATCH] Documentation/features: mark BATCHED_UNMAP_TLB_FLUSH doesn't apply to ARM64 Message-ID: <20210308125946.GA26015@willie-the-truck> References: <20210223003230.11976-1-song.bao.hua@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210223003230.11976-1-song.bao.hua@hisilicon.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 23, 2021 at 01:32:30PM +1300, Barry Song wrote: > BATCHED_UNMAP_TLB_FLUSH is used on x86 to do batched tlb shootdown by > sending one IPI to TLB flush all entries after unmapping pages rather > than sending an IPI to flush each individual entry. > On arm64, tlb shootdown is done by hardware. Flush instructions are > innershareable. The local flushes are limited to the boot (1 per CPU) > and when a task is getting a new ASID. > So marking this feature as "TODO" is not proper. ".." isn't good as > well. So this patch adds a "N/A" for this kind of features which are > not needed on some architectures. > > Cc: Mel Gorman > Cc: Andy Lutomirski > Cc: Catalin Marinas > Cc: Will Deacon > Signed-off-by: Barry Song > --- > Documentation/features/arch-support.txt | 1 + > Documentation/features/vm/TLB/arch-support.txt | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/Documentation/features/arch-support.txt b/Documentation/features/arch-support.txt > index d22a1095e661..118ae031840b 100644 > --- a/Documentation/features/arch-support.txt > +++ b/Documentation/features/arch-support.txt > @@ -8,4 +8,5 @@ The meaning of entries in the tables is: > | ok | # feature supported by the architecture > |TODO| # feature not yet supported by the architecture > | .. | # feature cannot be supported by the hardware > + | N/A| # feature doesn't apply to the architecture > > diff --git a/Documentation/features/vm/TLB/arch-support.txt b/Documentation/features/vm/TLB/arch-support.txt > index 30f75a79ce01..0d070f9f98d8 100644 > --- a/Documentation/features/vm/TLB/arch-support.txt > +++ b/Documentation/features/vm/TLB/arch-support.txt > @@ -9,7 +9,7 @@ > | alpha: | TODO | > | arc: | TODO | > | arm: | TODO | > - | arm64: | TODO | > + | arm64: | N/A | > | c6x: | .. | > | csky: | TODO | > | h8300: | .. | Acked-by: Will Deacon Will