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 78FAD154449; Tue, 2 Jul 2024 10:23:57 +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=1719915838; cv=none; b=pnkv5eSdkYGLDaWZ87SlmTFRU7nxih4S5ZTg0m9WPzXonD3fUuJIHn3PZ8quOVEEkq3gF1SjAQYTY1k2BCQPef5ILdictQztC/bijR8VaZ/A6Mr1zmHf5rZ/KJYx7dnIY4B1K/f6ZqS8nxjt/nV5gET0eSl95HapbNjbD8NXovU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719915838; c=relaxed/simple; bh=qa4CkARPGsFqAiGL1ve5C5ZCSijr/lHdCXNuTNLg2FY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=e7ISb7FDwcurKlzWG+L/rTsbVwaIzcq0VzRjwvG6D/GE6sLS4ViHI+rbrhdB4qZzg6LJ9mJviF7feozmK8viEmZ5THW7QzTxwCJW//HfDyBEYyhkYnmwDs6XD+p5NArk7Vt3r3DRV6iSwhxhj4VekZWBgAuo/F8qnTVUx4iltxs= 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=kGUDfGYy; arc=none smtp.client-ip=90.155.92.199 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="kGUDfGYy" 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=qa4CkARPGsFqAiGL1ve5C5ZCSijr/lHdCXNuTNLg2FY=; b=kGUDfGYy6kZfabLc3NZBycQA8f SunCUsB1kh0ibA+xuFK8YKZIAiK4q8X/afBzEF86ZgHw6IJRmaM32RlHdtaTM/lYxHJZ/8FeUpXZT +A9XSC1Q7857XhrXRgsT7sULtIurNahdx7iRA3eMFZNRrRZWC/N2S0shOplkyUAqbSfOYsrfNrnNU nmVz3XV7d1qan2PShzSLQWhF6dszGRiQg5/WTTUt+HP4BB9IdzBA0AGhBl7ay7VKoHYGycJ+CsPqK Bsu6ci7wAo5hB1gfX7LDjQH7FcyPqMIZosWlC4t9IC30mUs/vI73N4iuXsRkKVlT7AaWwEaFyfcFB nfjAvxhQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOafy-00000009o48-0WPy; Tue, 02 Jul 2024 10:23:54 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id B1E9C300694; Tue, 2 Jul 2024 12:23:53 +0200 (CEST) Date: Tue, 2 Jul 2024 12:23:53 +0200 From: Peter Zijlstra To: Andrii Nakryiko Cc: linux-trace-kernel@vger.kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, oleg@redhat.com, mingo@redhat.com, bpf@vger.kernel.org, jolsa@kernel.org, paulmck@kernel.org, clm@meta.com Subject: Re: [PATCH v2 00/12] uprobes: add batched register/unregister APIs and per-CPU RW semaphore Message-ID: <20240702102353.GG11386@noisy.programming.kicks-ass.net> References: <20240701223935.3783951-1-andrii@kernel.org> 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: <20240701223935.3783951-1-andrii@kernel.org> On Mon, Jul 01, 2024 at 03:39:23PM -0700, Andrii Nakryiko wrote: > This patch set, ultimately, switches global uprobes_treelock from RW spinlock > to per-CPU RW semaphore, which has better performance and scales better under > contention and multiple parallel threads triggering lots of uprobes. Why not RCU + normal lock thing?