From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 7C53F25A641; Tue, 28 Jan 2025 13:29:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738070943; cv=none; b=u/MSVcmZnHLc8L2d2yLRwnnA2yIp65Zg1BNHaRAxBAvVufHaBGKRfmJEg+HXG6PzW7mJgQOyHgOslpXeRlBjM0FADxs0+Uh9SToOSvCESa1LNROLlg65KYkPuBOgv3i+WVdJsXkVtLasGPAPKORVPLR2+Evf3aAEqSUgufs+s/0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738070943; c=relaxed/simple; bh=PrGeKq/cekNtXGN1zCTehiAgqi/kdPssC9gRbMyTsCQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DEJV1yL4Ziy4NFjebfoaD478/2SQIxAa+tlPrm7H57pOWrGBvI+eUsBbLV+ezXzIjJJ/2Y1CV/HKctKKjbVI0bubmbCOygIbhcY+WS/U2GmHgaiSAreeZh2BdQPED8rjx0aNJVaBQxr1c33soZk64uaVP6JLhhL0UhVhJdA7rX4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=gRQxCYDg; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="gRQxCYDg" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=vHxSgCjH7Naq9fEg2BykBRzu4+AX2crR6qBiGVHNJ6U=; b=gRQxCYDghfIccrNaLLDgq71koW cbn8M55jMoaw/7Gu43iSQumys+MFp2fdEB3wKLkORWjTHBdKyI6uFK9kMCSu67SLMtau0DSIe6NOR IDGmN4MMja+Vsm9aAO2uwgPFrwiaOqvx8tMgzYg9HcTBARv472856ZZfxCz57r8KOtLuDMYf00Bf+ zf+ti+iwA9uS310ecDukRGjsu07e9Watp/S+4EKV6JC2G/YY8E64s7TJPQ/iJyQKndK3gdff6jjXr zGfhedTNZmktMSP7O66WYU5nMciSAPqTpEvXNjyI4quHeItKTBiZU1odouzgtMLGHoPqeA4InM249 TCH5MwPA==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tcle4-0000000AeXF-18uI; Tue, 28 Jan 2025 13:28:48 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 9BD5F30050D; Tue, 28 Jan 2025 14:28:47 +0100 (CET) Date: Tue, 28 Jan 2025 14:28:47 +0100 From: Peter Zijlstra To: David Hildenbrand Cc: kernel test robot , Qi Zheng , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, Andrew Morton , Dave Hansen , Andy Lutomirski , Catalin Marinas , David Rientjes , Hugh Dickins , Jann Horn , Lorenzo Stoakes , Matthew Wilcox , Mel Gorman , Muchun Song , Peter Xu , Will Deacon , Zach O'Keefe , Dan Carpenter , Rik van Riel Subject: Re: [linus:master] [x86] 4817f70c25: stress-ng.mmapaddr.ops_per_sec 63.0% regression Message-ID: <20250128132847.GB505@noisy.programming.kicks-ass.net> References: <202501281734.d408a35b-lkp@intel.com> <46ea4509-0f38-4b22-bd91-f05c68db2562@redhat.com> <20250128113100.GB7145@noisy.programming.kicks-ass.net> <2c599f1f-f63b-4504-a026-46bf73954124@redhat.com> Precedence: bulk X-Mailing-List: oe-lkp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2c599f1f-f63b-4504-a026-46bf73954124@redhat.com> On Tue, Jan 28, 2025 at 12:39:51PM +0100, David Hildenbrand wrote: > On 28.01.25 12:31, Peter Zijlstra wrote: > > > I recall a recent series to select MMU_GATHER_RCU_TABLE_FREE on x86 > > > unconditionally (@Peter, @Rik). > > > > Those changes should not have made it to Linus yet. > > > > /me updates git and checks... > > > > nope, nothing changed there ... yet > > Sorry, I wasn't quite clear. CONFIG_PT_RECLAIM made it upstream, which has > "select MMU_GATHER_RCU_TABLE_FREE" in kconfig. > > So I'm wondering if the degradation we see in this report is due to > MMU_GATHER_RCU_TABLE_FREE being selected by CONFIG_PT_RECLAIM, and we'd get > the same result (degradation) when unconditionally enabling > MMU_GATHER_RCU_TABLE_FREE. Ah, yes, put a RHEL based config (as is the case here) should already have it selected due to PARAVIRT. But the thing is, that same paravirt crud will then map paravirt_tlb_remove_table() to tlb_remove_page() on native, effectively disabling the whole thing again. It's only for actual virt stuff, that tlb_remove_table() is used. These patches from Rik take all this stuff out and always use tlb_remove_table().