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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8112FC433EF for ; Wed, 24 Nov 2021 21:59:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F2A476B0075; Wed, 24 Nov 2021 16:58:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id ED9E76B0078; Wed, 24 Nov 2021 16:58:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA0B46B007B; Wed, 24 Nov 2021 16:58:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0002.hostedemail.com [216.40.44.2]) by kanga.kvack.org (Postfix) with ESMTP id C6C2F6B0075 for ; Wed, 24 Nov 2021 16:58:49 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 84C9818122A5F for ; Wed, 24 Nov 2021 21:58:39 +0000 (UTC) X-FDA: 78845188758.23.B471A82 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf22.hostedemail.com (Postfix) with ESMTP id 32462193C for ; Wed, 24 Nov 2021 21:58:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=//KBPE5SMQ1jDsaGVvNOxvpTpPtfZdPZBVxETIdKBt8=; b=JN+wvFOSa2W3XyDr9iLxgj4/pS NwuN2DNqNv7gFzkJL2sGkYlyyGRoBUbWOrIBHaXPDm1iGvcLRKqiJ/bZiEfD/fjP7Z2UnYoBeyGas oPspTxjI/X6mKEnEtEG+QLUSXkzSnenabR/+zy6if4GgwnayuZUr5yqzzbc5WgXY1PYORsrH95QU9 C3SLvF1geJCwyR2NmF5ksA1ir51KbssWpKzFpRUsjwDyqytal+WsPalPuiBKoL/zZMObjPw2Jp4e2 vh++WDRJraJ8dTjmENAyrfMk+nxmcXMDxJEnVKMhaklvLXCZJKox0NZ8rX+ZfnAdHOSzf+ySD9gUE m5YdKJxQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mq0Hh-003Y3o-Tr; Wed, 24 Nov 2021 21:58:34 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 3E62C986843; Wed, 24 Nov 2021 22:58:34 +0100 (CET) Date: Wed, 24 Nov 2021 22:58:34 +0100 From: Peter Zijlstra To: Peter Oskolkov Cc: Ingo Molnar , Thomas Gleixner , Andrew Morton , Dave Hansen , Andy Lutomirski , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Paul Turner , Ben Segall , Peter Oskolkov , Andrei Vagin , Jann Horn , Thierry Delisle Subject: Re: [PATCH v0.9.1 3/6] sched/umcg: implement UMCG syscalls Message-ID: <20211124215834.GI721624@worktop.programming.kicks-ass.net> References: <20211122211327.5931-1-posk@google.com> <20211122211327.5931-4-posk@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211122211327.5931-4-posk@google.com> X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 32462193C X-Stat-Signature: yqdwzph5b7cncfsdni91bncrm5d7f6n3 Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=JN+wvFOS; dmarc=none; spf=none (imf22.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org X-HE-Tag: 1637791117-637468 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: On Mon, Nov 22, 2021 at 01:13:24PM -0800, Peter Oskolkov wrote: > + if (abs_timeout) { > + hrtimer_init_sleeper_on_stack(&timeout, CLOCK_REALTIME, > + HRTIMER_MODE_ABS); Using CLOCK_REALTIME timers while the rest of the thing runs off of CLOCK_MONOTONIC doesn't seem to make sense to me. Why would you want to have timeouts subject to DST shifts and crap like that?