From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3E3581EEA2A for ; Tue, 18 Feb 2025 07:49:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739864965; cv=none; b=YiRDGEQMkeM3HeZprRT5lyV8Du6klyNgfQUAja7tqaa196HO0ByiHmtZLh1Sy5RLWdM+Q9Ut7e24dzj/1bhTNsid9urdNK3onO14vURkHuOTYJvELVMlhg9B11IlcKjaAbh9v/92k/nQKtXnocnnFv+fb+iCAP+shE2oXxVm6LQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739864965; c=relaxed/simple; bh=GkKM+DBOVd6orqINq/RQKJoYmvqEfIBoyz/KfGtJob0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=a8bN4ApFd2KTcXQwWEOyF1Ptz0PeXv03sgJIp8mivtsw02zLCgdkLNlxoGQ5N3DDRaEsA3D7fpSj+Zxcv+hgm+WlPi2ZXhAAG8m4DKPnknr4Ur6USZPoIINhLGDsl5cwgx2v42h3FuJo9WpfxAjYk8nDIi5YpTOCUnVx0+KB8nE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=O+b2CziQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="O+b2CziQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9646FC4CEE2; Tue, 18 Feb 2025 07:49:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739864965; bh=GkKM+DBOVd6orqINq/RQKJoYmvqEfIBoyz/KfGtJob0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=O+b2CziQI7QBIXRcVlCnvy5ky1X8c21WGDfIkounmiyZyG/vLjdrK0+gdRVNq/qe+ aMTnIo081BdrszrIrscjueQ6ioi7qyOCmD1sk7Tn6gb66SYCLf2FCeG/I9IkubTS1G nj6l3H/rdy4ijnFbwxXKv4llKeMtCxJupXiKUVx8= Date: Tue, 18 Feb 2025 08:49:22 +0100 From: Greg KH To: jaywang-amazon Cc: stable@vger.kernel.org Subject: Re: [PATCH] x86/i8253: Disable PIT timer 0 when not in use Message-ID: <2025021817-jockstrap-urging-d01f@gregkh> References: <20250217202434.11659-1-wanjay@amazon.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250217202434.11659-1-wanjay@amazon.com> On Mon, Feb 17, 2025 at 08:24:34PM +0000, jaywang-amazon wrote: > From: David Woodhouse > > [upstream commit 70e6b7d9ae3c63df90a7bba7700e8d5c300c360] > > Leaving the PIT interrupt running can cause noticeable steal time for > virtual guests. The VMM generally has a timer which toggles the IRQ input > to the PIC and I/O APIC, which takes CPU time away from the guest. Even > on real hardware, running the counter may use power needlessly (albeit > not much). > > Make sure it's turned off if it isn't going to be used. > > Signed-off-by: David Woodhouse > Signed-off-by: Thomas Gleixner > Tested-by: Michael Kelley > Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org > > (cherry picked from commit 70e6b7d9ae3c63df90a7bba7700e8d5c300c3c60) > > Cc: stable@vger.kernel.org # v5.15 > > Signed-off-by: jaywang-amazon Why all the blank space here? And why not cc: all of the people who did this patch on it? Also your name needs to be fixed up. Please work with your coworkers on getting this all right so we don't have to do this type of basic reviewing for you. All of your recent backprots suffer from this and can not be taken, sorry. greg k-h