From patchwork Tue Oct 25 13:58:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna-Maria Behnsen X-Patchwork-Id: 618624 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 17943FA3740 for ; Tue, 25 Oct 2022 13:59:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231836AbiJYN7c (ORCPT ); Tue, 25 Oct 2022 09:59:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231546AbiJYN70 (ORCPT ); Tue, 25 Oct 2022 09:59:26 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3917A29C; Tue, 25 Oct 2022 06:59:25 -0700 (PDT) From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1666706363; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vvmb4wfRRA26uf1ExR6XWWcWf4ly6fbBq4i3VJ/TCEY=; b=LwzQPpX+Ny/PxpUuI5+8qcVrqQfT+WjE7/NENxhUShNmOEw/iTf37CJ4FwRBqsuzl/u5z+ wnhOmVBSHuvvQyowXC9m+wb5s2TtJpaDZsDxGrXBFbncS/SR0qiDtqA+1c8pv+rwlX9rfm aKX3hwqW3fvLBrefg8HwPjql35faDPU5ouq3uzKL5MPAVoxJLVIEeSj2Pgi26Jjk/kIKG7 eEX9DHBUgsGP6QEHMDXA0SIbTKgCLNyh0PJSXLS9Q2AxQ0fmesw+KOHPOCPl+ANDsd6Tw8 jjKvOFiZGe8GwKADdu1P0m0wi7qVYiwGlix0MqBMBM89OEmMaLhlzh/DYDe1LQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1666706363; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vvmb4wfRRA26uf1ExR6XWWcWf4ly6fbBq4i3VJ/TCEY=; b=8N2pUT0OaCAesECVu/HpMphD9DDy2spXcuoPHDFPo3FjS0DZYJm78WHzj9wdoRKnl4Q9t9 /tIBD5wqb5wMx+Cg== To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , John Stultz , Eric Dumazet , Thomas Gleixner , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, Arjan van de Ven , "Paul E. McKenney" , Frederic Weisbecker , Rik van Riel , Anna-Maria Behnsen Subject: [PATCH v3 05/17] timer: Rework idle logic Date: Tue, 25 Oct 2022 15:58:38 +0200 Message-Id: <20221025135850.51044-6-anna-maria@linutronix.de> In-Reply-To: <20221025135850.51044-1-anna-maria@linutronix.de> References: <20221025135850.51044-1-anna-maria@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Thomas Gleixner To improve readability of the code, split base->idle calculation and expires calculation into separate parts. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Behnsen Reviewed-by: Frederic Weisbecker --- kernel/time/timer.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index f34bc75ff848..cb4194ecca60 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1727,21 +1727,20 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) base->clk = nextevt; } - if (time_before_eq(nextevt, basej)) { - expires = basem; - base->is_idle = false; - } else { - if (base->timers_pending) - expires = basem + (u64)(nextevt - basej) * TICK_NSEC; - /* - * If we expect to sleep more than a tick, mark the base idle. - * Also the tick is stopped so any added timer must forward - * the base clk itself to keep granularity small. This idle - * logic is only maintained for the BASE_STD base, deferrable - * timers may still see large granularity skew (by design). - */ - if ((expires - basem) > TICK_NSEC) - base->is_idle = true; + /* + * Base is idle if the next event is more than a tick away. Also + * the tick is stopped so any added timer must forward the base clk + * itself to keep granularity small. This idle logic is only + * maintained for the BASE_STD base, deferrable timers may still + * see large granularity skew (by design). + */ + base->is_idle = time_after(nextevt, basej + 1); + + if (base->timers_pending) { + /* If we missed a tick already, force 0 delta */ + if (time_before_eq(nextevt, basej)) + nextevt = basej; + expires = basem + (u64)(nextevt - basej) * TICK_NSEC; } raw_spin_unlock(&base->lock);