From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f54.google.com (mail-qv1-f54.google.com [209.85.219.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 994021BAEFB for ; Fri, 30 Aug 2024 18:01:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725040909; cv=none; b=KYgMCPZjIzIFLNs9Layo5wuBGAVnvWvDtYMT6m0R7NR8l9LGZ3QxdG6o/C/fqeaqag63LQXooQxLLBMdxTDV5PK3IKBJy2342bds+OZ0r0VXfsjSWy7muzCd9rxYUiP/0cEeI28HQRqcGZ9mf7MyfpMP4uVmo4g3L/EU44mqaxM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725040909; c=relaxed/simple; bh=Wkn0NEovL5pCoQtw6/Lg6viGcF8IybsMpWYEL2WoUK0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bjnSP4Z9slsb2Fa9RDHyu+L53Ga+C0Gu7OCBHIv00kJBa1V06NSHY4yKwDtfIN2WXSyHVGTpiR1hza+t2v26wWfbLhqEkuJCD09LdSetfMyHgO6bzqJDqdceaR+cE0f+eZLa5GjaTc3u3WKaO9a+UCHz7hAzlP2iVh7G17ueAxM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=manifault.com; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.219.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=manifault.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-qv1-f54.google.com with SMTP id 6a1803df08f44-6c331543ef0so11763646d6.1 for ; Fri, 30 Aug 2024 11:01:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725040906; x=1725645706; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Wkn0NEovL5pCoQtw6/Lg6viGcF8IybsMpWYEL2WoUK0=; b=CZ/uQrAvQPVe5LeChb5dhQMOee5JtRlFQlhU6aRRxRMHWg4rKD8FkmPKWQZyigFGqN NSPkBd0fkNyXfXoflVtspBDD8FBog8WO6mlphUXtfss6Qzw4AO3WwIQps9vnObqlB+S0 X51LwU7IjCV1Zu34n+vx1HvhcL4MsS61bQ+pyjuCydAGa6w0vAhN6DnznxwKEUFhID23 T8v/2SelZh+On3SHhknbwwjOWzY86cKNuZevL00BiVvlXRTmmhHrUumwCF1w/BB0vSs7 tykTwrgssHPSbRR2IdDMLLHhy+7vzs8M+EEJHA2Rfo6sTBMSJvx4sssdh4xsn0mFrVFZ 39vw== X-Gm-Message-State: AOJu0YzEcNGcKkrNpDgZKWLwcDU8ei6N/G0ychVTOF97sCJIKFypRDoR bj6YBazi7EW+7OvMyWRMu/3Ub+wXAocMfwnoQd8mQjqY/kEZNYu0 X-Google-Smtp-Source: AGHT+IGi8PtFIdGpLbtbMSqPQ5nsIzNW3hmafcEJy3zWtjxNxMjT3PYH8lHOx/IGULdUFR1lo94v9Q== X-Received: by 2002:a05:6214:4a01:b0:6bd:70ce:e413 with SMTP id 6a1803df08f44-6c35540cd90mr3362506d6.30.1725040906276; Fri, 30 Aug 2024 11:01:46 -0700 (PDT) Received: from maniforge (c-76-141-129-107.hsd1.il.comcast.net. [76.141.129.107]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6c340bff5bfsm16727946d6.36.2024.08.30.11.01.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Aug 2024 11:01:45 -0700 (PDT) Date: Fri, 30 Aug 2024 13:01:43 -0500 From: David Vernet To: Tejun Heo Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , kernel-team@meta.com Subject: Re: [PATCH v2 2/2 sched_ext/for-6.12] sched_ext: Use sched_clock_cpu() instead of rq_clock_task() in touch_core_sched() Message-ID: <20240830180143.GF5055@maniforge> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="NNswZFIh3UIH4OeF" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.13 (00d56288) (2024-03-09) --NNswZFIh3UIH4OeF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 30, 2024 at 07:54:41AM -1000, Tejun Heo wrote: > Since 3cf78c5d01d6 ("sched_ext: Unpin and repin rq lock from > balance_scx()"), sched_ext's balance path terminates rq_pin in the outerm= ost > function. This is simpler and in line with what other balance functions a= re > doing but it loses control over rq->clock_update_flags which makes > assert_clock_udpated() trigger if other CPUs pins the rq lock. >=20 > The only place this matters is touch_core_sched() which uses the timestamp > to order tasks from sibling rq's. Switch to sched_clock_cpu(). Later, it = may > be better to use per-core dispatch sequence number. >=20 > v2: Use sched_clock_cpu() instead of ktime_get_ns() per David. >=20 > Signed-off-by: Tejun Heo > Fixes: 3cf78c5d01d6 ("sched_ext: Unpin and repin rq lock from balance_scx= ()") > Cc: David Vernet > Cc: Peter Zijlstra Acked-by: David Vernet --NNswZFIh3UIH4OeF Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQRBxU1So5MTLwphjdFZ5LhpZcTzZAUCZtIJBwAKCRBZ5LhpZcTz ZIYJAQCdYxgMELf+q/vFrKrBoEn9X0lxej0CT2EuGACsCXd8VwEAkA624PfK1nuV tZZx1/ohkQFEtv8U54R6wne2YCvjngw= =poOo -----END PGP SIGNATURE----- --NNswZFIh3UIH4OeF--