From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) (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 8772618B474 for ; Wed, 25 Sep 2024 13:21:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=167.114.26.122 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727270510; cv=none; b=Pai477fhdvIKux7B3tDbfzrwq1WClkz4eUNuc87Wz+BUDZwjKSvOui1hq6d9DuQpJQl70tpopZY8hzmsdlB1dYSPgGkW56LrzQWNIhSBYUEETiwWGZmd8PWMZFekQcvariBPYk0jFc/DAeejF94pMAvr1iEE3eZsLM5D6DuorM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727270510; c=relaxed/simple; bh=b3Uax3+rp7gtwhp//ajM56k9gXFv76k3I57QzMJ/Jic=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=Nr4UjQiYC/Qd2KXCM8HsZDNS9DkMsaOIw0t1LzmR7EwwDfaSsqyPn+g6UDvbm6xaERIuyZn1KluavUAYZdQ+s5R4jmxSmDqbtXMu4r1t6XmMsF+jAIW0j9wJy0ZiWhJJZOx5DpO+CCrUc4esdRiIEWfBsIN/kVL6iC2zEJmWhQk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=nPlSkVvc; arc=none smtp.client-ip=167.114.26.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="nPlSkVvc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1727270508; bh=b3Uax3+rp7gtwhp//ajM56k9gXFv76k3I57QzMJ/Jic=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=nPlSkVvcakqjs0Pf5vAv5qs75CAE4pm0O+LM83/WA1QNYIOxm5VMP5e1CncMDM6mu XTy8gvC3iaHwaKKA+AQ/IbBOi1tZjzfYYh9GEznLuGVk7fiBq6zbYxMy7Ee6FLyjsI O2B1bpVv1NjrSJ/qGcQZBpUEiypcAC7Vn6e+WdcW+I0YRTXyG8bYlBY4RkUXwUWhoO 4z73XTbzvWAAf66z4NXmUehWTL0D9UTdhyNLIwcFC7lrT93Vtn+ec2CTwhC2gxrDuH yOvv0ZJ0AlBhDMuPlHKGjF0zNcqe/S8ofDorLNq6jafLN3z8cUU1nkX6gdtdV5lk0P K0lS1ikXWI4XA== Received: from [192.168.126.112] (unknown [147.75.204.251]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4XDHSM2sF6z1M9H; Wed, 25 Sep 2024 09:21:39 -0400 (EDT) Message-ID: Date: Wed, 25 Sep 2024 15:20:59 +0200 Precedence: bulk X-Mailing-List: lkmm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 1/4] hazptr: Add initial implementation of hazard pointers Content-Language: en-US From: Mathieu Desnoyers To: Boqun Feng Cc: Jonas Oberhauser , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-mm@kvack.org, lkmm@lists.linux.dev, "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Uladzislau Rezki , Steven Rostedt , Lai Jiangshan , Zqiang , Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Mark Rutland , Thomas Gleixner , Kent Overstreet , Linus Torvalds , Vlastimil Babka , maged.michael@gmail.com, Neeraj Upadhyay References: <20240917143402.930114-1-boqun.feng@gmail.com> <20240917143402.930114-2-boqun.feng@gmail.com> <55975a55-302f-4c45-bfcc-192a8a1242e9@huaweicloud.com> <4167e6f5-4ff9-4aaa-915e-c1e692ac785a@efficios.com> <48992c9f-6c61-4716-977c-66e946adb399@efficios.com> In-Reply-To: <48992c9f-6c61-4716-977c-66e946adb399@efficios.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2024-09-25 15:10, Mathieu Desnoyers wrote: [...] Cleaner without goto in the user code: #include #include static inline bool same_ptr(void *a, void *b) { asm goto ( "cmpq %[a], %[b]\n\t" "jne %l[ne]\n\t" : : [a] "r" (a), [b] "r" (b) : : ne); return true; ne: return false; } int x; int v[2]; int main(void) { if (same_ptr(v, v + 1)) x = 1; printf("%d\n", x); return 0; } -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com