From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f51.google.com (mail-wm1-f51.google.com [209.85.128.51]) (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 864093A6B83 for ; Fri, 22 May 2026 08:07:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779437257; cv=none; b=gGYEYagctdV1MvVccPV31R0d9jFZSBC9CYfaJqf9gu5E4uqkyHLtb0gKsXBCjM2kyneligOEQFHE7V6Fv4Gt1umipEn9jDGgFUGojHk7BW+bUJqKWLER0FOXm2nvBULDnC74VAF0NTcJlKnbD8izFHCZbFJtqySoYVjuqobQxN4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779437257; c=relaxed/simple; bh=cf90c8kEq9ntPS+lGbFuVQLu5a/kvkOrYBO4KWpVtzI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SjvjcVfPKoZ8pJXzZi9Ag+90B/TR7XxtYvMKo3/fPDu4nWh9EvEibr1IiSf68mqyvxJ0JrRUMZvhKeShb4maj36I+KD4okr3D2mQNY/s0DVXDKSIR4/MtPXQy9R0mXNkjHP5urqC1IQbG5ePbVRf+IcK34ld3njxdUwju1cWeQo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=RkJhcgqj; arc=none smtp.client-ip=209.85.128.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="RkJhcgqj" Received: by mail-wm1-f51.google.com with SMTP id 5b1f17b1804b1-4903fd19957so9254705e9.1 for ; Fri, 22 May 2026 01:07:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1779437254; x=1780042054; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=NCfWqKpUWwctVcLEDfZQ5LqGQZYGOWGmCGj7yU2aV8s=; b=RkJhcgqjfqQL4d7y6rpMThlk2Xm0DhBnBXIHYrwMn3WOHQqA4T9osgHcQY1kBWbKEz CM3GzXBfMEcFMU8G0WKXZMgHJpgWLSqHYF7Zo3KKGX1D7GzXCjDnPbYvPzXWBo3duWEY nVAQw7oA0geWce7ZME2GrvRrv0hRjZ8J6ElaVoyKNuiwIpw7771kwWwWARgh9oRKAHgP dJ0x4PUXv1zElQHfwcJFVt0KZvDtIC6mgf1xusJYFLVgnbLk5UimBiP2OFwqcx2clGEK QkLgW/MyOR0dr4REz3aa1q+9lVIl/Ngz+RtgWwNuUwPVnms9IOCXHtNAhHb0waRzImcQ iYBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779437254; x=1780042054; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NCfWqKpUWwctVcLEDfZQ5LqGQZYGOWGmCGj7yU2aV8s=; b=XUk+FWRjohyM7u+7Nwzix9fDDMb7kaPODe2MfYqaBAQvX9M9HokkPUjT+2r/g3XkmR zlgkzBmkzdklHNv8t9kjBJij/+Nx0+ngiB7mEu5OFG+m0KHaJA/kD88MBIydw27+XVtx fkpAUy5RnUS3fig2Hr5I88vVRvdJDfUPWCC6SarSGGob6TFjmeb8fmeIlo8fMqjwRkUb oxyJcxUDfJuEbdPwCT8X9ZYAyDLRa5QXb5lcd1sWY1n9+lSl6PYePIg2xT48+VOFXDKl v5pkWd2JiDFxiWA4WDf3YLRpAmbKPubTp48DErXUPpkcl4EpsRJzWYQIePpXA/64esTY Yyuw== X-Forwarded-Encrypted: i=1; AFNElJ9vjd5Su3rTj5soPlJGXM3fX7CjGw/rWbdPTvd+UwUASn1E0FGr0Q0ugJ2HCrsb+zYlJsfy3ntT15/I22M=@vger.kernel.org X-Gm-Message-State: AOJu0Ywv1A5Tekklf7PdWVaC05QSQRkY9kJeHju/ET7YogCMz+ctz/7r FvHNBFeG9SoN05FBzrQa9tPl+yXLdeYXpytQuKh/ulR+8xM9vWfyIcD7NoWNIPAbGLc= X-Gm-Gg: Acq92OHW7NEk+qWkTddOVqO861ZzLxC03DjpUtNoatCBqqj12IM43638oOBlRGha16a jtqElOdgIiXEs9e6aGlCCROo1W4Yyrd3ABen2U42oNJsSRPgUT+t8H017B66xpwjhN9C7hGd6qA 3NbwbDh/mWGjGBHDPf3cgAB/59TAsY+gml50lpWLyu2ZQtl7B/albxGk4g2NpnTOer2V+k56nUT huzLtj9zqHPbCGCHEhuz380d0ZnnrfnOOw1i/eX9XlU71zKu0OIut8Zh87CbtCfAPi3i/l2fWLR Z0aDl4HytWgxqKeLLbFg49Bj8WmYZ4k/xl0nIfG/nEgBF2lzFGBt8dAUZ/dGMwkdQKxegO7ZVRE XEijlbcB/pX/Ar2MskYbVmcw4Z85SUs12TZgkFgsoQbUeH1v3aOnBjTeLVK6N2Artf9E1PSYHaa ljOnzvUJjTJA9mfeG1uFLBoIlteA== X-Received: by 2002:a05:600c:1992:b0:48a:9428:5522 with SMTP id 5b1f17b1804b1-490426bc7dcmr28379815e9.16.1779437253852; Fri, 22 May 2026 01:07:33 -0700 (PDT) Received: from pathway.suse.cz ([176.114.240.130]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-490417a3be1sm17297285e9.3.2026.05.22.01.07.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 May 2026 01:07:33 -0700 (PDT) Date: Fri, 22 May 2026 10:06:35 +0200 From: Petr Mladek To: Andrew Morton Cc: Feng Tang , paulmck@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] lib/nmi_backtrace: print out the CPUs which fail to respond to NMI Message-ID: References: <20260521030336.92172-1-feng.tang@linux.alibaba.com> <20260521153716.0e6da8366d3e2004e9e7cf97@linux-foundation.org> <20260521205326.06557d667beab85a21fd0a6f@linux-foundation.org> 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: <20260521205326.06557d667beab85a21fd0a6f@linux-foundation.org> On Thu 2026-05-21 20:53:26, Andrew Morton wrote: > On Fri, 22 May 2026 09:46:26 +0800 Feng Tang wrote: > > > > It's a nitpick, but > > > > > > : /* Wait for up to 10 seconds for all CPUs to do the backtrace */ > > > : for (i = 0; i < 10 * 1000; i++) { > > > : if (cpumask_empty(to_cpumask(backtrace_mask))) > > > : break; > > > : mdelay(1); > > > : touch_softlockup_watchdog(); > > > : } > > > : > > > : if (!cpumask_empty(to_cpumask(backtrace_mask))) { > > > : pr_warn("After 10 seconds, these CPUS still haven't responded to the NMI: %*pbl\n", > > > > > > Here we're hard-coding "10" in two places and in a comment. It would > > > be nicer to do > > > > > > #define FOO_TIMEOUT 10 > > > > > > then use that throughout. > > > > > > (bonus points for figuring out how to paste that "10" into the > > > pr_warn() control string rather than using %d!) > > > > How about this followon patch? > > Looks great. But you missed the fun part! > > --- a/lib/nmi_backtrace.c~lib-nmi_backtrace-print-out-the-cpus-which-fail-to-respond-to-nmi-fix-fix > +++ a/lib/nmi_backtrace.c > @@ -16,6 +16,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -79,8 +80,8 @@ void nmi_trigger_cpumask_backtrace(const > } > > if (!cpumask_empty(to_cpumask(backtrace_mask))) { > - pr_warn("After %d seconds, these CPUS still haven't responded to the NMI: %*pbl\n", > - NMI_BT_TIMEOUT_SEC, cpumask_pr_args(to_cpumask(backtrace_mask))); > + pr_warn("After " __stringify(NMI_BT_TIMEOUT_SEC) " seconds, these CPUS still haven't responded to the NMI: %*pbl\n", > + cpumask_pr_args(to_cpumask(backtrace_mask))); > > nmi_backtrace_stall_check(to_cpumask(backtrace_mask)); > } > _ With all the followup fixes, LGTM: Reviewed-by: Petr Mladek Best Regards, Petr