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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8B05EC433E9 for ; Mon, 15 Mar 2021 19:24:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1A27C64F51 for ; Mon, 15 Mar 2021 19:24:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A27C64F51 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lwn.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 745706B0036; Mon, 15 Mar 2021 15:24:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 71C626B006C; Mon, 15 Mar 2021 15:24:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5BD286B0070; Mon, 15 Mar 2021 15:24:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0034.hostedemail.com [216.40.44.34]) by kanga.kvack.org (Postfix) with ESMTP id 41AE16B0036 for ; Mon, 15 Mar 2021 15:24:41 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id F0394180AD820 for ; Mon, 15 Mar 2021 19:24:40 +0000 (UTC) X-FDA: 77923085562.06.AEDD41E Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) by imf24.hostedemail.com (Postfix) with ESMTP id 91272A00CFA1 for ; Mon, 15 Mar 2021 19:18:59 +0000 (UTC) Received: from localhost (unknown [IPv6:2601:281:8300:104d::5f6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id 19DF82E5; Mon, 15 Mar 2021 19:18:58 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net 19DF82E5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1615835938; bh=So9BxVVP4vJIybXhEmOBJxB5pieD4QyUvx0pbVCgp5I=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=mpxpQzoi39ZdBSexYO8A147/EiFJIj5SoXm+LXMnBxovMbOWbVB6aIxT2VQb1cNbO ip0xp770AKFuhIydaupQQHAkN8Xbcee6TyuidcwI9EJ47QxOhzeivCCr1bhdZBVMHJ H5ickUEj4++Vbq5B9J8JdydI7qyiosgyR9Q13mYmXrqp8bzgfWd/HwHFi3VBLfSrrI 37ieCOZ8AZ4b8wrxy1K+R4Pc3/Oh3yM9h8cKil32skwu5HcZBL/NTqu9KXLyoq2ejs cYu8/BkAW54GB8VAn/FKB56k2dmvGITUJy90NbeEmHgVdHG2wbN3oPPpkJa+PXGunt HYSc6IK0mVqlg== From: Jonathan Corbet To: Barry Song , linux-doc@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxarm@openeuler.org, Barry Song , Mel Gorman , Andy Lutomirski , Catalin Marinas , Will Deacon Subject: Re: [PATCH] Documentation/features: mark BATCHED_UNMAP_TLB_FLUSH doesn't apply to ARM64 In-Reply-To: <20210223003230.11976-1-song.bao.hua@hisilicon.com> References: <20210223003230.11976-1-song.bao.hua@hisilicon.com> Date: Mon, 15 Mar 2021 13:18:57 -0600 Message-ID: <87a6r42pjy.fsf@meer.lwn.net> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 91272A00CFA1 X-Stat-Signature: it3pyyk3e7shwuhc4wfehsxgqpyoj1am Received-SPF: none (lwn.net>: No applicable sender policy available) receiver=imf24; identity=mailfrom; envelope-from=""; helo=ms.lwn.net; client-ip=45.79.88.28 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615835939-502842 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: Barry Song writes: > 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(-) This had a conflict with the c6x removal, but I fixed that up and (finally) applied it, thanks. jon