From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 EC1A632F765; Fri, 24 Apr 2026 09:55:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777024528; cv=none; b=mgEV6QyEujAXkF5oEruOLwU5IezaKQQe8h5FPdclGY3AUEpLMpErzWLYca5lL4x5D5BP77GKotm4ysOmLawVFNk4xMfZieljcnkmzSWZWhluCG3wrhhQiNvtmcAxlHF7FZcGOR0evmQfmGtiD813F5zQ1MTCgbZ/egwUilrBXWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777024528; c=relaxed/simple; bh=B+3VBIk4qmI6ZFVHKHZJVYjnsomsgtk3uTy0nU5PpDc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BiMPLsKP9Tqa5y6J+hOosrrAXAWt6gYmapnRrcGaFX1P1lFnyIvZMc8qKwWsRHYy1LdR5aHFoGBaywpayYnx+B+AASITYM0GE1Om6xR8N541gGzBW+EAjTmZiaPkl32eUqjBcsWJ7XBF2RYcP532gN4/JW+gxLcmNNgbnQxES2s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=JX/NmvwL; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="JX/NmvwL" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=yTZeL8gIFJiYZDye2bbHTw0xhW2aKuxmuu1CaFtu798=; b=JX/NmvwLQuDJZSqHhjM6CL1hBL EtcmuZdffYsJjWoySfRWVyarSEDAqh7gL3QxCdXnmEMzpjRyJ6T37gY1NqlV8cAmkEL7krhRNxRZ/ tYda3xpkluwJ343rdxgS1KCXKYIfNtgp/zYxl3C2Iio10UrxeImXc2WV4ZvNaHR1N6MsowDytNMw0 tvQOgsL4KgwQq+CJXRwkGA0wbKGKsAQO3VGaCkpbrbqqE29EBHNXzzPF3/FObwpzwZKdtBeYN8uny go7X4VUgKSrSDbPJ5wyRaG4k+b4kZfvigqngdn/j45gAEyiU99L3S4GS1ld/WGlD1+ursIjH5FFxM zpqEDtVw==; Received: from 2001-1c00-8d85-4b00-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:4b00:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1wGDFr-0000000EX6V-24D3; Fri, 24 Apr 2026 09:55:23 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 1015630301B; Fri, 24 Apr 2026 11:55:23 +0200 (CEST) Date: Fri, 24 Apr 2026 11:55:23 +0200 From: Peter Zijlstra To: kernel test robot Cc: Thomas Gleixner , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, aubrey.li@linux.intel.com, yu.c.chen@intel.com Subject: Re: [linus:master] [sched] 96d1610e0b: will-it-scale.per_process_ops 2.8% regression Message-ID: <20260424095523.GE3126523@noisy.programming.kicks-ass.net> References: <202604241448.365c92f9-lkp@intel.com> 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: <202604241448.365c92f9-lkp@intel.com> On Fri, Apr 24, 2026 at 03:10:07PM +0800, kernel test robot wrote: > > > Hello, > > kernel test robot noticed a 2.8% regression of will-it-scale.per_process_ops on: > > > commit: 96d1610e0b20b5a627773874b4514ae922ad98f6 ("sched: Optimize hrtimer handling") > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > [still regression on linus/master 1d51b370a0f8f642f4fc84c795fbedac0fcdbbd2] > [still regression on linux-next/master 936c21068d7ade00325e40d82bfd2f3f29d9f659] > [still regression on fix commit eef9f648fb0e92618041f019d4bdcf7ae17cb743] > > testcase: will-it-scale > config: x86_64-rhel-9.4 > compiler: gcc-14 > test machine: 48 threads 2 sockets Intel(R) Xeon(R) CPU E5-2697 v2 @ 2.70GHz (Ivy Bridge-EP) with 64G memory > parameters: So this commit has lived in private trees (tglx and mine), has been in tip, in next etc. *WHY* do we only get this report now? This isn't the first time I see a regression report after things have hit Linus' tree. This is starting to get really annoying. The point of having this robot was to catch issues *before* they hit Linus, no? That said, looking back at will-it-scale reports, 2.8 seems to be pretty much in the noise range, no?