From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3343279F2 for ; Thu, 6 Jul 2023 09:53:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 277FEC433C9; Thu, 6 Jul 2023 09:53:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688637239; bh=Vme8i+8ZjqtCno6CMa53lKwCLxQgLuTEKq8y8x78RyY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K7oSQpH7enTD5ZMIXGersjb+eY+WfjWQlx23EVs5zrVRdsGfuA5hOU8OQRDadpMGR zEqbLacQL8xgg//uANI/Pl6VhMj39f/bjNmRu4GTXr1mkVZtqlain2RaoXt9HqZtnk 4zCANtybIAn2X5KQX+bN8AO5b0JId3ArIfsZEBOLhQzqDSV/jPXP+Q7n9qBOGO6UX4 hLyzSN9KUXNMpTSWY8PNvQGKLQtLuIAtukPmR47WXlJVgBm+hJ3FC/3YNqgwO8Nbgv 9LfraiT2DNi6NY9hrCpoV8srdK/tTXx63FZCy1rf9Ah0hXz9SmzXYZfwAmnwE1R9SH 6zRSCUyYxRkrQ== Date: Thu, 6 Jul 2023 11:53:56 +0200 From: Frederic Weisbecker To: Peter Zijlstra Cc: Valentin Schneider , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, x86@kernel.org, Nicolas Saenz Julienne , Steven Rostedt , Masami Hiramatsu , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Andy Lutomirski , "Paul E. McKenney" , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Josh Poimboeuf , Kees Cook , Sami Tolvanen , Ard Biesheuvel , Nicholas Piggin , Juerg Haefliger , Nicolas Saenz Julienne , "Kirill A. Shutemov" , Nadav Amit , Dan Carpenter , Chuang Wang , Yang Jihong , Petr Mladek , "Jason A. Donenfeld" , Song Liu , Julian Pidancet , Tom Lendacky , Dionna Glaze , Thomas =?iso-8859-1?Q?Wei=DFschuh?= , Juri Lelli , Daniel Bristot de Oliveira , Marcelo Tosatti , Yair Podemsky Subject: Re: [RFC PATCH 11/14] context-tracking: Introduce work deferral infrastructure Message-ID: References: <20230705181256.3539027-1-vschneid@redhat.com> <20230705181256.3539027-12-vschneid@redhat.com> <20230705224104.GE2813335@hirez.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: bpf@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: <20230705224104.GE2813335@hirez.programming.kicks-ass.net> On Thu, Jul 06, 2023 at 12:41:04AM +0200, Peter Zijlstra wrote: > On Thu, Jul 06, 2023 at 12:23:57AM +0200, Frederic Weisbecker wrote: > > If this is just about a dozen, can we stuff them in the state like in the > > following? We can potentially add more of them especially on 64 bits we could > > afford 30 different works, this is just shrinking the RCU extended quiescent > > state counter space. Worst case that can happen is that RCU misses 65535 > > idle/user <-> kernel transitions and delays a grace period... > > We can make all this a 64bit only feature and use atomic_long_t :-) Works for me :)