From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout02.his.huawei.com (canpmsgout02.his.huawei.com [113.46.200.217]) (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 A9643258ECB; Thu, 18 Dec 2025 02:18:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.217 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766024293; cv=none; b=Ym17H5lo69ELhuNL/g6rdxdjtX9nB+ze9ej9TKBegfoQWEcrdGAIb6XvMkRZ42Xaz9whEsKx4WXqDE/scmcxoki2R142WtTQph+y25A4ke7GL+xkkfNc65O+TQ5Gl+mtnIrBarLAbSMnsP+oHWhn0Tcy9TRjPDP3RPvngjbrN/k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766024293; c=relaxed/simple; bh=c8rJ6JMxZp9DaGNwOiUd7KigxG1YrnCIPSv6q0EhAh4=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=IWkknJ3RCv14zka4JOIATFUNetBqaQY44qQ9L8x+dK9Jra0994IGa8MK5FzjPd6WZCnvQY/o0JKHnsUrpjBNKcRg9yqbd07b1wFv2GD+7zmJ1O92rGfEGaCdJBkWxo2sOg5mkGFY9x8IpxoYS5pWQr6Irld/iETXoRVDkkGNDuU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=z8xS0Ku0; arc=none smtp.client-ip=113.46.200.217 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="z8xS0Ku0" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=mU9pFxcO0/m/HH3q3YJxOTDrfSR1HD2/oA7Tnb2zAg0=; b=z8xS0Ku07NSfMV0+Eyjw0tVZd+2KlX5/xZ9iNMjLJk7g7Ezu8uLL02LLnDzGNeOgBxj7LLSFL pyoGHKtcJlGOTfIO1UHDoVdjdSIj4M7daExWaLqQIJP/W/0uNfuyblKB5WilT14RNWJiKCJnB6D VJhJ83pyUdWc45DEopxByOQ= Received: from mail.maildlp.com (unknown [172.19.163.174]) by canpmsgout02.his.huawei.com (SkyGuard) with ESMTPS id 4dWvQ81r27zcb2h; Thu, 18 Dec 2025 10:15:12 +0800 (CST) Received: from dggemv705-chm.china.huawei.com (unknown [10.3.19.32]) by mail.maildlp.com (Postfix) with ESMTPS id F115814022E; Thu, 18 Dec 2025 10:18:06 +0800 (CST) Received: from kwepemq500010.china.huawei.com (7.202.194.235) by dggemv705-chm.china.huawei.com (10.3.19.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 18 Dec 2025 10:18:06 +0800 Received: from [10.173.125.37] (10.173.125.37) by kwepemq500010.china.huawei.com (7.202.194.235) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 18 Dec 2025 10:18:05 +0800 Subject: Re: [PATCH v2 1/3] mm: fixup pfnmap memory failure handling to use pgoff To: Ankit Agrawal CC: Neo Jia , Zhi Wang , Krishnakant Jaju , Yishai Hadas , "kevin.tian@intel.com" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Vikram Sethi , Jason Gunthorpe , Matt Ochs , "jgg@ziepe.ca" , Shameer Kolothum , "alex@shazbot.org" , "akpm@linux-foundation.org" , "nao.horiguchi@gmail.com" References: <20251213044708.3610-1-ankita@nvidia.com> <20251213044708.3610-2-ankita@nvidia.com> From: Miaohe Lin Message-ID: Date: Thu, 18 Dec 2025 10:18:05 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemq500010.china.huawei.com (7.202.194.235) On 2025/12/18 2:10, Ankit Agrawal wrote: >>>        i_mmap_lock_read(mapping); >>>        rcu_read_lock(); >>> @@ -2226,9 +2230,12 @@ static void collect_procs_pfn(struct address_space *mapping, >>>                t = task_early_kill(tsk, true); >>>                if (!t) >>>                        continue; >>> -             vma_interval_tree_foreach(vma, &mapping->i_mmap, pfn, pfn) { >>> -                     if (vma->vm_mm == t->mm) >>> -                             add_to_kill_pfn(t, vma, to_kill, pfn); >>> +             vma_interval_tree_foreach(vma, &mapping->i_mmap, 0, ULONG_MAX) { >>> +                     pgoff_t pgoff; >> >> IIUC, all vma will be traversed to find the final pgoff. This might not be a good idea >> because rcu lock is held and this traversal might take a really long time. Or am I miss >> something? > > Hi Miaohe, the VMAs on the registered address space will be checked. For the nvgrace-gpu > user of this API in 3/3, there are only 3 VMAs on the registered address space (that are > associated with the vfio file). Oh, I see. Thanks for your explanation. :)