From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) (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 0919917085A; Sat, 28 Sep 2024 11:50:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=14.137.139.154 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727524238; cv=none; b=qRzNiEwWdVnZwUCNKDa1T2Fbl8BhhXJvGioem8haQUYDIO6lEbnZYxKgGY5XgBGRswhL/ftebp7VF3fNnyUZOznEb7/hT8l6u9ZzEDdNDTTCsokMMkHWZDwiQbF+Et75dMYPMYBLU2UDLFdVOasQN//OtvcLG6UNiWscp5wVgOE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727524238; c=relaxed/simple; bh=8P3Zw7MFYAZvL1cGHyTuojhG3OvEjU0fxG4TGXibf5s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=X0vaKZVpKU9+za7ireHkf0ubYbcKsVQrdZhDXlhFbHqDaJxlBuLkMSU62LexizeUFxPMcLXp0GpswE56MvHgNqP6wwaKeONS/R6GCNfUDscBiKUjzs7+xq/9pMK4ZYn/5vB9TMiaoCbZXkDTNGOTQJLodwW6kaPVBQ8C/6ed/co= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=14.137.139.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.18.186.29]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4XG4kC4QzHz9v7JM; Sat, 28 Sep 2024 19:24:51 +0800 (CST) Received: from mail02.huawei.com (unknown [7.182.16.27]) by mail.maildlp.com (Postfix) with ESMTP id 8CB4E1401F0; Sat, 28 Sep 2024 19:50:32 +0800 (CST) Received: from [10.81.205.100] (unknown [10.81.205.100]) by APP2 (Coremail) with SMTP id GxC2BwBHqcl47fdm4VvRAQ--.57124S2; Sat, 28 Sep 2024 12:50:31 +0100 (CET) Message-ID: <42709627-8bb9-4f9f-beeb-dde9bd420022@huaweicloud.com> Date: Sat, 28 Sep 2024 13:50:13 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 1/1] hpref: Hazard Pointers with Reference Counter To: Mathieu Desnoyers , Boqun Feng , "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, Will Deacon , Peter Zijlstra , Alan Stern , John Stultz , Linus Torvalds , Frederic Weisbecker , Joel Fernandes , Josh Triplett , Uladzislau Rezki , Steven Rostedt , Lai Jiangshan , Zqiang , Ingo Molnar , Waiman Long , Mark Rutland , Thomas Gleixner , Vlastimil Babka , maged.michael@gmail.com, Mateusz Guzik , rcu@vger.kernel.org, linux-mm@kvack.org, lkmm@lists.linux.dev References: <20240921164210.256278-1-mathieu.desnoyers@efficios.com> <2ca589bc-2a60-48ef-95a0-d9ee4a814dea@efficios.com> From: Jonas Oberhauser In-Reply-To: <2ca589bc-2a60-48ef-95a0-d9ee4a814dea@efficios.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID:GxC2BwBHqcl47fdm4VvRAQ--.57124S2 X-Coremail-Antispam: 1UD129KBjvdXoW7GFW7JF1ftF4UXr1DZry5Jwb_yoWxAwcEvw nrCa15Ar43JF4xW347JF13GrWfJrWvkr4UJw18CF47Zry5ZFnxCFn3CryIy3WfG3yUC3s0 qryrX3yUZr9xWjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbx8YFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwV A0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x02 67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267 AKxVW8JVW8Jr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2 j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7x kEbVWUJVW8JwACjcxG0xvEwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AK xVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F4 0E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_Wryl IxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxV AFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j 6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jxCz tUUUUU= X-CM-SenderInfo: 5mrqt2oorev25kdx2v3u6k3tpzhluzxrxghudrp/ Thanks for your response, Am 9/28/2024 um 1:33 PM schrieb Mathieu Desnoyers: > > This is a userspace prototype. This will behave similarly to a userspace > spinlock in that case, which is not great in terms of CPU usage, but > should eventually unblock the waiter, unless it has a RT priority that > really prevents any progress from the emergency slot owner. > > On my TODO list, I have a bullet about integrating with sys_futex to > block on wait, wake up on slot release. I would then use the wait/wakeup > code based on sys_futex already present in liburcu. Oh, I see. I think if it is for userspace then it really should use wait/wakeup as you said. Best wishes, jonas