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[23.128.96.18]) by mx.google.com with ESMTP id r24si7662303ejy.432.2021.09.24.09.52.42; Fri, 24 Sep 2021 09:53:11 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=lx6uytud; dkim=neutral (no key) header.i=@linutronix.de header.s=2020e header.b=4n7ArgCx; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245240AbhIXMK0 (ORCPT + 99 others); Fri, 24 Sep 2021 08:10:26 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41742 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239965AbhIXMKZ (ORCPT ); Fri, 24 Sep 2021 08:10:25 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1632485331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=SBUHTNr0sCPxkBiTM2SkIyDC24mPjzNNzFCj27YDFMU=; b=lx6uytudcp0xd/4w8tORhQm6wFFb9F0vYhX34CIpAjqTNkEndcxY3JGtQntf2xOiJDLJdV hSKxoWbbTmJz7Bpp7vDBUXMdvneK00gZtsLtSAGzxE2Nbfbz74qml5P1JT7MyQW0Fb1hrZ A/lGUcR50kOu/jvgOvpmf/QcexiAROT/OmRHk31TlaKbdqwQPuGr3qrR0lutUmaov45Qez admV9fVIY0z3SEx9AoLRJBHo5aCn8hNGEn9mRDFFYvzbFT+zDoObS3fZAVm0MBssKcPlQI 1PK8c578h8ND1hUzNeLSXd4CKqdun60nrrQ310WtEnnD5b6p1ch3swgdl4kc2g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1632485331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=SBUHTNr0sCPxkBiTM2SkIyDC24mPjzNNzFCj27YDFMU=; b=4n7ArgCxkJXLSq4ISErp2O0BC9f9yksbARwk8NCmVGD2Q7dm7tZqeEEgBlWb8xYHQsfCwj 9Cn+bMRMSlCqyHAQ== To: maninder1.s@samsung.com, "fweisbec@gmail.com" , "mingo@kernel.org" Cc: "linux-kernel@vger.kernel.org" , Vaneet Narang , AMIT SAHRAWAT , Chung-Ki Woo Subject: Re: [Issue] timer callback registered with mod_timer is getting called beforetime In-Reply-To: <20210924065310epcms5p69dd47a510faaa6bf68c243e02f2d0186@epcms5p6> References: <20210924065310epcms5p69dd47a510faaa6bf68c243e02f2d0186@epcms5p6> Date: Fri, 24 Sep 2021 14:08:50 +0200 Message-ID: <87mto2dvl9.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 24 2021 at 12:23, Maninder Singh wrote: ? > As we checekd code if CPU responsible for updating jiffies value(lets > say CPU0) has interrupts disabled for 60 ms and in mean time other > CPU(CPU1) registers new timer for (jiffies + x) value. its callback > will be called before time. So you run some stuff for 60ms with interrupts disabled and now you are asking what's wrong? The answer is simply: Keeping interrupts disabled for 60ms is wrong. Anything else is just a symptom. Thanks, tglx