From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.189.121.228 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792916025; b=NPRG2QmnsA252Z3XL/MD42Y85VVYa0JZooLtrS+pTXuEZe3Il71GH9C2NjjL78GV1GEP hOJ3x6XP3Qo/P6xzvwc7zNqmVX+qwwfTtZpenaQcI3nydU5d9jd/G/yLp6ATNd6XVs92R PFYobwG3oupoC4qelh3yF9goDVDS3j2m9LDuXZQamX08S2/naBRqicf8KwbkgwGJ2/SGz DOkFyZLMKjMK7/kxAf495eCVA/X2vzR52EAj9h8+w888Oc4e7+BWBlWYnyzb/nXgSdGz4 iuxC9N2klEY7GAgf2pUfG4DS7OaMw4/0thn32f6gFzTDryjRib2gMg9Z+UTVeHWzajw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792916025; h=DMARC-Filter:Message-ID:DKIM-Signature:Subject:From:To:Cc:Date: In-Reply-To:References:Content-Type:MIME-Version; bh=EKyPeaxDN5KkkiMtpzosRjM1dGahqBT+/A8ey72yYsM=; b=rdl57YrT+a0flCh7vEwydJ/yP4bKtGlKD3m8KOUpiDGxRYOwOcllP6P8kzOU4sZrcC44 iTzEULGbwjiriLswxvG6jDDmP1uwdHlm/xC9jcMa/TH4JKGq3dg1+EhtTtxE0AMcjnp6M +8nXNzSi6yujqu4SMvI3hsnuDasVisq9+gx9+L3V4mAImoRFY9OGt8kHCMhzSa64D8bmC O2/0avmSYJ4YfdnStnizGYpa4ecyyK2XcnfYtNwrWJKV/YE7t6PD5oG+wJOEfh/pFdaUQ oMsm7h7+A8Cn2eibRe3w/CuC/fFKoiXA32m5z5VWSMkhslBMxgu+O2gDpnd9INJkhCA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=itx.no; spf=pass smtp.mailfrom=itx.no; dkim=pass header.d=itx.no header.i=@itx.no header.a=rsa-sha256 header.s=mx.itx.no header.b=mpHpmLKt; arc=none smtp.remote-ip=91.189.121.228 Received: from mx.itxnorge.no (itx-kvm-14.itxnorge.no [91.189.121.228]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AA48606A31B for ; Sun, 25 Oct 2026 08:13:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6AA48606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=itx.no Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=itx.no Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=itx.no header.i=@itx.no header.a=rsa-sha256 header.s=mx.itx.no header.b=mpHpmLKt Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=itx.no; s=mx.itx.no; t=1792916015; 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=EKyPeaxDN5KkkiMtpzosRjM1dGahqBT+/A8ey72yYsM=; b=mpHpmLKtfUYngs2u5aGFdd2Vuvbj9ForenHZMhaaTK8Wd8S6bBsIMSURN1CL+UkcC5nWDL 0yazXsiOL52l5e9NiabzpkHDQTMyRMLJZ2JgcaPd1haTNmZSQsYD0doGB8hQdlTRR+uNrn 19qIh7hpeCYs3x+mg2LpUJroky9Wg/0= Subject: Re: WARNING: kernel/sched/cputime.c:481 at kcpustat_dyntick_stop+0x8b/0xa0, CPU#0: swapper/0/0 (was: [PATCH v3] sched/cputime: Don't account idle time twice after dyntick-idle) From: Stian Halseth To: Paul Menzel Cc: Frederic Weisbecker , Thomas Gleixner , Anna-Maria Behnsen , Ingo Molnar , Peter Zijlstra , Shrikanth Hegde , regressions@lists.linux.dev, linux-kernel@vger.kernel.org Date: Sun, 25 Oct 2026 09:13:34 +0100 In-Reply-To: References: <20261007142950.547604-1-stian@itx.no> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-8XBARo2aAwhejeO4wymt" X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 --=-8XBARo2aAwhejeO4wymt Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Paul, On Sun, 2026-10-25 at 08:27 +0100, Paul Menzel wrote: >=20 > On a Dell XPS 13 9360 (Intel Kaby Lake, 4 CPUs), Linus=E2=80=99 master fr= om > the 7.4 merge window, warned once during boot (of five boots having > your change included), in the first idle period of CPU 0: Thanks for the report. I believe the warning _is_ the bug here, and that the accounting itself is correct. Currently running tests on a follow up patch, suggesting to remove WARN_ON_ONCE, with a comment explaining why. Once tests are done, I'll finish writing up the commit message which explains my reasoning in detail. Should follow shortly. /Stian --=-8XBARo2aAwhejeO4wymt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTK1ph9OaYoND1R57zoeAEuJe36VgUCat26LgAKCRDoeAEuJe36 VrAbAQC19We8l643k08zZUDFsT/IUjYFUG0kCWRvV/btl80NNgD+LKGhV/5e1Akv kyMMdGZ0X3eI4Fp3plX3OyJihMmbSgQ= =uPfL -----END PGP SIGNATURE----- --=-8XBARo2aAwhejeO4wymt--