From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F54DC32793 for ; Wed, 18 Jan 2023 13:40:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229802AbjARNkb (ORCPT ); Wed, 18 Jan 2023 08:40:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230341AbjARNjw (ORCPT ); Wed, 18 Jan 2023 08:39:52 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C94F066FB8; Wed, 18 Jan 2023 05:09:56 -0800 (PST) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1674047362; h=from:from:reply-to:subject:subject: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=/6TzDShPYUNhKSU2xPYdtTZMZX/aEdeeSUD3KZBBydU=; b=ZhAjyVrqwVngYKwtheIJfVNwxQmS9uVXWR0gRK08TYomkEtNgb3u3+LN/9zg04hgZ6clfq MRReHEto9s5y6J/buGPwvTWEgh4qEOOTk6Msb8h9y1oK0eljwB5p8hhkGtv9KSOntnxXhc NAtgSUNCPh0Dm63vb2EVbREry3gKEcJ0SfSeygbQP1UbqC9g3/S766hX7R5tG1cuxVmTV5 QBJbbv770/wNOKgLI954c9YNaJV194Xl4iacOUTCAV+8SazK50/Q320e6LbOGlwSKSoGmt OE9EmM+7ZA8TsxLXROdt3Ssm9Bn7QeOKtUI2zCuLyyCjs2Pb16UHfsXH7YyBoA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1674047362; h=from:from:reply-to:subject:subject: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=/6TzDShPYUNhKSU2xPYdtTZMZX/aEdeeSUD3KZBBydU=; b=/qObata+kcBzO4TB56IOdgKgFcxEk9ZLP3fzlG0WDJgqiEKiI+uZ2uJ8XvMscADLovljyh 6N4opwSGTDvnWTDg== To: Johan Hovold Cc: Johan Hovold , Marc Zyngier , x86@kernel.org, platform-driver-x86@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Hsin-Yi Wang , Mark-PK Tsai Subject: Re: [PATCH v4 19/19] irqdomain: Switch to per-domain locking In-Reply-To: References: <20230116135044.14998-1-johan+linaro@kernel.org> <20230116135044.14998-20-johan+linaro@kernel.org> <87mt6gkez4.ffs@tglx> Date: Wed, 18 Jan 2023 14:09:22 +0100 Message-ID: <87o7qwhtvh.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 18 2023 at 10:51, Johan Hovold wrote: > On Tue, Jan 17, 2023 at 10:50:39PM +0100, Thomas Gleixner wrote: >> On Mon, Jan 16 2023 at 14:50, Johan Hovold wrote: >> > The IRQ domain structures are currently protected by the global >> > irq_domain_mutex. Switch to using more fine-grained per-domain locking, >> > which may potentially speed up parallel probing somewhat. >> >> Does it or not? >> >> If not then why adding all this churn for no real value? > > It probably doesn't make much difference, but Marc wanted per-domain > locking: > > > I'd really like to avoid a global mutex. At the very least this should > > be a per-domain mutex, otherwise this will serialise a lot more than > > what is needed. Sure it serializes more than what is needed, but the real question is whether it matters. If it does not matter then I prefer KISS over a just because we can optimization. Thanks, tglx