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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62BCCC77B75 for ; Sat, 6 May 2023 17:35:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229742AbjEFRfi (ORCPT ); Sat, 6 May 2023 13:35:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjEFRfe (ORCPT ); Sat, 6 May 2023 13:35:34 -0400 Received: from out3-smtp.messagingengine.com (out3-smtp.messagingengine.com [66.111.4.27]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFCD21BFA; Sat, 6 May 2023 10:35:32 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 7977C5C00B2; Sat, 6 May 2023 13:35:29 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute6.internal (MEProxy); Sat, 06 May 2023 13:35:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm3; t=1683394529; x=1683480929; bh=Lg ril5syRG3Ut6fnOTry0JCF7zd9RTUfKTlmm/rB3KM=; b=C/0ceNnZ8vvqL16A/L S1MDBFo/Ujz4SMgYRuQ1JErJPQVFNayyE7nw/yjDlgK5CLim1CQ5ZOpdkuxcqU+8 yz5caZtt6VnhE0RsE35uiRPsac+FOxrTNFEjzmUQYZK8LYkLhY3CJPYXzcZBnf8U iXy3DoIssXHsEjFBpWkD+BNWZ4fjgl8fgABKYyRvW36j21pqwfg3BjlQLOOwYXnF NWbNRhoS+HHPLop1vjlCQJg4g7plsbnOwignykTvJTA0DSJCnXo532XUbC5Zd0tW 3dWhs7SW5k1lMy5kLp4cf9gcXbyV2H0n4NkSobc2r56nqE6IYNDt43Vdnan1CukG hPrQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; t=1683394529; x=1683480929; bh=Lgril5syRG3Ut 6fnOTry0JCF7zd9RTUfKTlmm/rB3KM=; b=OiSABjPe+TBGIPO5lqmLC183Ka/jl wVm2TFfB2WGZSf1c/Iseewplo8LhzY+F2vZw2dvFICgtGAqGlWIehqblUzSpAPuW Q+S/dPjO+0H/pdGMasNpXJOdbJ+HSEa2Ut9DYSGPJ1IUHZiKbtoY7h7/hPbNmit9 oFitY3ytXH1jj2bMtzZ8oMT0vqXUd40f5lQTPjZLwsgM6WcItuNViO8Zd47myK4g Oz1I65/rSUB2LN9k4D7uPjs3oWxjwS7idl6rSk7GeagvvIyaqJKmu7kr/hks4UWj yfTIPxjdgh+g0lPlqamzdqXJFjqi3Rxtd4hgH+ILyhorle5y9UNoabz6A== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrfeefgedgleduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepofgfggfkjghffffhvfevufgtsehttdertderredtnecuhfhrohhmpedftehr nhguuceuvghrghhmrghnnhdfuceorghrnhgusegrrhhnuggsrdguvgeqnecuggftrfgrth htvghrnhepffehueegteeihfegtefhjefgtdeugfegjeelheejueethfefgeeghfektdek teffnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomheprg hrnhgusegrrhhnuggsrdguvg X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 92132B60086; Sat, 6 May 2023 13:35:28 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-386-g2404815117-fm-20230425.001-g24048151 Mime-Version: 1.0 Message-Id: <315e7ec2-169c-4c4b-93df-485380bc0852@app.fastmail.com> In-Reply-To: <20230505133426.d70a6599d9a729496b68a70c@linux-foundation.org> References: <20230503013608.2431726-1-nphamcs@gmail.com> <20230503013608.2431726-3-nphamcs@gmail.com> <20230505133426.d70a6599d9a729496b68a70c@linux-foundation.org> Date: Sat, 06 May 2023 19:35:05 +0200 From: "Arnd Bergmann" To: "Andrew Morton" , "Geert Uytterhoeven" Cc: "Nhat Pham" , "Johannes Weiner" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, bfoster@redhat.com, "Matthew Wilcox" , linux-api@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v13 2/3] cachestat: implement cachestat syscall Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 5, 2023, at 22:34, Andrew Morton wrote: > On Thu, 4 May 2023 19:26:11 +0200 Geert Uytterhoeven > wrote: > >> > arch/x86/entry/syscalls/syscall_32.tbl | 1 + >> > arch/x86/entry/syscalls/syscall_64.tbl | 1 + >> >> This should be wired up on each and every architecture. >> Currently we're getting >> >> :1567:2: warning: #warning syscall cachestat not implemented [-Wcpp] >> >> in linux-next for all the missing architectures. > > Is that wise? We risk adding a syscall to an architecture without the > arch maintainers and testers even knowing about it. > > The compile-time nag is there to inform the arch maintainers that a new > syscall is available and that they should wire it up, run the selftest > and then ship the code if they're happy with the result. The usual approach is for the author of a new syscall to include a patch with all the architecture specific changes and Cc the architecture maintainers for that. Note that half the architectures get the entry from include/uapi/asm-generic/unistd.h, so adding it there does not necessarily trigger adding each maintainer from scripts/get_maintainer.pl. The only real risk in adding a new syscall is passing __u64 register arguments that behave differently across architectures, or using pointers to data structures that require a compat handler on some architectures. I watch out for those as they get sent to me or the linux-arch list, and this one is fine. Arnd