From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (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 E9B7FA23 for ; Sat, 8 Feb 2025 03:17:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738984669; cv=none; b=HHcoKmQxTxIzYJvCDQLvGohlOE47Os5YRWh/Pn83Wik69yJrlynJrZ4Qhma6xh/YCgIqOeD3GnKmEtEc9wr2NSYIDZwe4AgYku9jyoxtXUyPd9HG8EDy5xZgwHrJs1nDet6c+MFBg9Iy4myxawwWzQWUnYULUYBQ600uqUxv5pI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738984669; c=relaxed/simple; bh=/UPr5zPx5T4FSgK65mwgjPcgywZ4qh8s3ZC4e1gvk/M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=n4QPQ1u0AtJVfm121XhHiEOiSmHv8PYGP34hiwzML7x9ra4CYShzxBF//eS0t7QJwCFRP/mDza/8mCCZAhvqazM0C17bzqIJ7NUtM7cOJSRCqn4ddvc6IHj9eeARPY9nkO2YQKLbYU8kcWLoSRw/wPhwbH3MlP5ch7LC8adTZK0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=OcRAQPve; arc=none smtp.client-ip=178.60.130.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="OcRAQPve" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=JelDmvVCl54XiASmEJAB3CTSP86k4kOSQrqZHzkfw2g=; b=OcRAQPve0gXqkJK5PYQZiAOl2q Y7mTExz2R44OC0LXKvrNWJmeox+vs+C24b3O4CwQ8Q02E+Pwe1Mbc2t1vfkUHgbuCbbgqz/7pT5pE c8amTn/hmICzhW/pehfI3Ju4axJEc6mnB+aJ+OtfqXrCLJYwxHOOrYOQRwtO7CO4FGVnuWIQPxX+3 AjDG5oHgYur54cUFJ08nYvqyf1kdqfLRL/NaCOzGlEi480RwApxpSUMFtgt7r7WuuKZAGFeZfHh8T GhLXeu9RmSUC+cXzlfnyJ1YGoXIz9sj8VDZyKRYaYWDN/UZW9rwhN281t9GZ37wxCk5qttdv+JCXo aq4ptcmw==; Received: from [58.29.143.236] (helo=[192.168.1.6]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1tgbLQ-006Eux-QL; Sat, 08 Feb 2025 04:17:31 +0100 Message-ID: Date: Sat, 8 Feb 2025 12:17:26 +0900 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] sched_ext: Add a core event and update scx schedulers To: Andrea Righi , Tejun Heo Cc: void@manifault.com, kernel-dev@igalia.com, linux-kernel@vger.kernel.org References: <20250207031338.393045-1-changwoo@igalia.com> From: Changwoo Min Content-Language: en-US, ko-KR, en-US-large, ko In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Tejun and Andrea, On 25. 2. 8. 06:45, Andrea Righi wrote: > On Fri, Feb 07, 2025 at 11:38:31AM -1000, Tejun Heo wrote: >> I'm not sure. BPF schedulers should be able to avoid getting the default >> slice. Hopefully, with the added visibility, this should be easier now. I'm >> not sure how much overriding the default value in ops helps in terms of >> control. It's a very half-way measure. Instead, how about we add tracepoint >> to scx_add_event() so that folks who want to get backtrace of specific >> events can get them easily so that it's easier to debug where these counts >> are coming from? Let's just make it easier to avoid these events. > > Yeah, that's a valid point, the implicit SCX_SLICE_DFL should be seen as a > countermeasure for unhandled situations. Instead of fixing the > countermeasure itself we should try to prevent it, if it proves to be > problematic. And I like the idea of having a way to backtrace specific > events. I agree that adding a tracepoint to scx_add_event() and __scx_add_event() is a defenitely useful extension to further investigate what's going on. I will take a look. Regards, Changwoo Min