From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (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 8724B2EBB8D for ; Wed, 11 Mar 2026 13:12:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773234745; cv=none; b=Nd8m2AQgZw5p6hMzYbGT/AR+uXyfvzcjUNN9upTtEoc5tb4nkmMraUIWIH50YMGQtU3FsrHhflbEj9dd2uNrC+ByLGeRcYtwipHH+G2rE0Y9WlW0yhBKWepcA18EFqbxYjhIlKlM25iioLsnVuLbG38XOPCHaeuZ+choT9hN6QU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773234745; c=relaxed/simple; bh=klNijv9VeZCuILMMNUP4dkrWpUjGN6TZWVyYSOEH0mc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D+C5+fw757izTg8+r0LjaJ4Sij5wnwtrG8PEMALFbRUNfOLlbFYEG1qPzylML92d0Mumt6xcVL9/PsmJ40mpeJZGvQ2TVvyUM1ychGAFUX5qttyvzSTYsDHD5H9Xv0NlwuALf3fpCBbWEW1JaVV2s5+cA+ixArfc66xnRN0V+Rs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=Ii2aVCaU; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=SPbAAUrM; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=Ii2aVCaU; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=SPbAAUrM; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="Ii2aVCaU"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="SPbAAUrM"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="Ii2aVCaU"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="SPbAAUrM" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id DEA4B4D357; Wed, 11 Mar 2026 13:12:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1773234742; h=from:from:reply-to: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=eEsFilC8x48DoYuD12G2GruYm9kvDHinwy2SB11tyPg=; b=Ii2aVCaUmi3FKr3X1uFYBKWtVqH/u2MhksnWvTYo4mfnsy0s5DZKKn79tE3EgeHO35iUSN M+QM43lnmKuedhpKTXcEHA0kmxvBKHYe3jPwJBbt/hzICdNUHKwKAuvEddCCuRWKmWEcOe K6X7vOV2W4G6Uq9bC8yiAFjkNs0G6zg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1773234742; h=from:from:reply-to: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=eEsFilC8x48DoYuD12G2GruYm9kvDHinwy2SB11tyPg=; b=SPbAAUrMfx1e5rCaZ+MNJgpVHh8CYQrgYxS3wFutxGvDXUlc2Bkpyj5DruoO24Fn/PVxLd tDTDfoBtsf0rr+Bg== Authentication-Results: smtp-out1.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=Ii2aVCaU; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=SPbAAUrM DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1773234742; h=from:from:reply-to: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=eEsFilC8x48DoYuD12G2GruYm9kvDHinwy2SB11tyPg=; b=Ii2aVCaUmi3FKr3X1uFYBKWtVqH/u2MhksnWvTYo4mfnsy0s5DZKKn79tE3EgeHO35iUSN M+QM43lnmKuedhpKTXcEHA0kmxvBKHYe3jPwJBbt/hzICdNUHKwKAuvEddCCuRWKmWEcOe K6X7vOV2W4G6Uq9bC8yiAFjkNs0G6zg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1773234742; h=from:from:reply-to: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=eEsFilC8x48DoYuD12G2GruYm9kvDHinwy2SB11tyPg=; b=SPbAAUrMfx1e5rCaZ+MNJgpVHh8CYQrgYxS3wFutxGvDXUlc2Bkpyj5DruoO24Fn/PVxLd tDTDfoBtsf0rr+Bg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id CF8853FA27; Wed, 11 Mar 2026 13:12:22 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id tHyiMjZqsWljRgAAD6G6ig (envelope-from ); Wed, 11 Mar 2026 13:12:22 +0000 Received: by incl.suse.cz (Postfix, from userid 1000) id 3A023FE189; Wed, 11 Mar 2026 14:12:22 +0100 (CET) Date: Wed, 11 Mar 2026 14:12:22 +0100 From: Jiri Wiesner To: Thomas Gleixner Cc: LKML , "Paul E. McKenney" , John Stultz , Waiman Long , Peter Zijlstra , Daniel Lezcano , Stephen Boyd , x86@kernel.org, "Gautham R. Shenoy" , Daniel J Blueman , Scott Hamilton , Helge Deller , linux-parisc@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org Subject: Re: [patch 5/5] clocksource: Rewrite watchdog code completely Message-ID: References: <20260123230651.688818373@kernel.org> <20260123231521.926490888@kernel.org> <87y0k21vro.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@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: <87y0k21vro.ffs@tglx> X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_RHS_NOT_FQDN(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; ARC_NA(0.00)[]; MISSING_XM_UA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCPT_COUNT_TWELVE(0.00)[16]; MIME_TRACE(0.00)[0:+]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FREEMAIL_ENVRCPT(0.00)[gmx.de]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; FREEMAIL_CC(0.00)[vger.kernel.org,kernel.org,google.com,redhat.com,infradead.org,linaro.org,amd.com,quora.org,eviden.com,gmx.de,alpha.franken.de]; RCVD_COUNT_THREE(0.00)[3]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns,suse.de:dkim,suse.de:email]; RCVD_TLS_LAST(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Queue-Id: DEA4B4D357 X-Spam-Flag: NO X-Spam-Score: -4.01 X-Spam-Level: On Sun, Mar 08, 2026 at 11:05:31AM +0100, Thomas Gleixner wrote: > On Wed, Feb 25 2026 at 19:13, Jiri Wiesner wrote: > > On Sat, Jan 24, 2026 at 12:18:01AM +0100, Thomas Gleixner wrote: > >> To address this and bring back sanity to the watchdog, rewrite the code > >> completely with a different approach: > >> > >> 1) Restrict the validation against a reference clocksource to the boot > >> CPU, which is usually the CPU/Socket closest to the legacy block which > >> contains the reference source (HPET/ACPI-PM timer). > > > > The UEFI picks the boot CPU so the kernel does not have control over > > that. On the other hand, I think the CPU that is connected to the > > southbridge chip (by DMI or PCIe) will be selected in the majority of > > UEFI implementations. > > Picking a remote node CPU would be insane, but yes BIOSes are insane by > definition. Yes, I was mostly just being paranoid. Please include: Reviewed-by: Jiri Wiesner in the next version of the patchset. -- Jiri Wiesner SUSE Labs