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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A0FCC3DA49 for ; Tue, 30 Jul 2024 22:30:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2CB026B0089; Tue, 30 Jul 2024 18:30:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 252F16B008A; Tue, 30 Jul 2024 18:30:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F3D76B008C; Tue, 30 Jul 2024 18:30:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id E31926B0089 for ; Tue, 30 Jul 2024 18:30:14 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 99C69A010E for ; Tue, 30 Jul 2024 22:30:14 +0000 (UTC) X-FDA: 82397863548.01.FF40403 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf26.hostedemail.com (Postfix) with ESMTP id 78DB714000D for ; Tue, 30 Jul 2024 22:30:12 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Rv3KZy9V; spf=pass (imf26.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1722378557; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=y5kNYpg9eUUfaVFQlHs3iXOjdZpeVmxNiRg//4lRozI=; b=sMt5RF8xVbfAgY0UnOySpHb6H5OL/9By1NZP+jqS4in0AyRSLz8MZ3AcpdpPpvUSpWDMkg kTTtqP54BQhGqskki/56lfle9N5N1A5+mDKW6oTxEqoXXZ56djf9VNj7qkQIA8SNvv0yGM GVhsjx78ZCjPEqz3hNDxsmHAlvCQNGI= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1722378557; a=rsa-sha256; cv=none; b=001v3JrNJrVzbtYcXe2nWLIJsV8kwc9yvNNTgeKOYzTfvcOl7VC/XFXvntLGsu+sSm0US/ ghsnMMccXlNZh8mPBLDjJbyqDt8i9OCv67gnyQ6KfrxAZgNEsJjyJ/sogM+lute9g4VCUo vEDwPoqkUDh8ReZVQjkampCfwjoF1Xc= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Rv3KZy9V; spf=pass (imf26.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722378611; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=y5kNYpg9eUUfaVFQlHs3iXOjdZpeVmxNiRg//4lRozI=; b=Rv3KZy9VX6Z2vq4IL/0y0fiuNsujfRHEREhDGI4FRl4bNtuPBv3ZTq3D+Pf8AOWgVtV4Zd x+Z/1ePc0s/fu+d4QAa9Ui+tRYLBI7xN/33Fyf3gZC7hyEAEz8m808TxUUDOnGDdoOlfNa +Kjs4NEkV4ds+83q3qvnjUHtlbPSqvg= Received: from mail-oo1-f69.google.com (mail-oo1-f69.google.com [209.85.161.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-541-81Xed3gPOXuP8xgQIGwb3Q-1; Tue, 30 Jul 2024 18:30:10 -0400 X-MC-Unique: 81Xed3gPOXuP8xgQIGwb3Q-1 Received: by mail-oo1-f69.google.com with SMTP id 006d021491bc7-5d5d0d392dfso856834eaf.0 for ; Tue, 30 Jul 2024 15:30:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722378609; x=1722983409; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=y5kNYpg9eUUfaVFQlHs3iXOjdZpeVmxNiRg//4lRozI=; b=QQiOi2wfhPCKpyOxYB9NSGCsd1on/bt/7n7oRHnqYtpABYy0jz7F5EWQEpGUSjT/Tp 3OG5Q8Oh06vneOc/8WbSpY8TB2uziq19tToSPlrs/9Ta+XYbOwoCUU8vSPWqk3GjhQdD blu/56XNw/+poQ04eCNJ6y8gnBeVvSP3cnH0GlldRwKAxD/WSk/yH0m8mrcpaqTU7rv7 x2q86N2YrCsRWa4hItHghMfLfQ0m1PhtVRRzkkknO0eHRN0hB5QJj7mDd7V+PTrYVGat jIr5e8ULtOFOPkNIMdhlN4x+2/kEzIhg/WNg0VUIxh44PeBCS0oJsMgPdC74uToB+R/J ohdA== X-Forwarded-Encrypted: i=1; AJvYcCVQT/U61fMYgOOzVZ3/3lV+561cFWzXRaWseSj6fn8qZlFhcd50ktW3ZXMMm7ggwbl7H4iHUHbKRVJMuvW7edmdLWQ= X-Gm-Message-State: AOJu0YzBRyNtwmOqn7AUP7NCEo/AfylrTSw/0JCXXvlfuPdiUxsP0YzY GaFn5SficEi3SSh3UHl0q9uyEyiGohn5sOQyq3UEzM6arppvb6PbeVxiXVdW8AZqwZL3t1lbUBX N2WNbZsewSReWUj0WiRYpurMVbbEorYtXj/GB/gxl4FXz/V9n X-Received: by 2002:a4a:a542:0:b0:5c7:b587:40a7 with SMTP id 006d021491bc7-5d5b15373c5mr10749401eaf.1.1722378609513; Tue, 30 Jul 2024 15:30:09 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFJByCxdD1t4UZwfqqPdgCZsn2gbVDdIJGfCxxyPNKDP8T1DbcoLV+Wd5i1D2Eds9HHRRl71Q== X-Received: by 2002:a4a:a542:0:b0:5c7:b587:40a7 with SMTP id 006d021491bc7-5d5b15373c5mr10749390eaf.1.1722378609089; Tue, 30 Jul 2024 15:30:09 -0700 (PDT) Received: from x1n (pool-99-254-121-117.cpe.net.cable.rogers.com. [99.254.121.117]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6bb5bcffd18sm45807036d6.15.2024.07.30.15.30.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jul 2024 15:30:08 -0700 (PDT) Date: Tue, 30 Jul 2024 18:30:06 -0400 From: Peter Xu To: James Houghton Cc: David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Oscar Salvador , Muchun Song , Baolin Wang Subject: Re: [PATCH v2] mm/hugetlb: fix hugetlb vs. core-mm PT locking Message-ID: References: <20240730200341.1642904-1-david@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-Stat-Signature: thq8scw5r1bywgywaw8kfzkm9z8c1wyd X-Rspamd-Queue-Id: 78DB714000D X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1722378612-577807 X-HE-Meta: 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 GpQN51KC ToL1ClmOuvHFL4/F/791KmO0tQMoe9N8qBMprR/3yJERjnDmlmGl7J9gz5XmGMw5dLxsLIJpEa/t3/vF0aFS27N72/DThy0UtnS643V+a9HOSrJhBgpy5+PFghg4duAbES6eg1QifTz2t5gbBDKPe9pu1gwAy0VvD0mCXs2Z4jjFCDwjgz3MMuYRg2AVQX1VilN6OKFXj832CwWBH0Pbbf4VwSMFWsyXepG0Bb5srI54q+McIurz8uhcxruSKuO840vJ/8pt3ajEwP4hkTBWSuwTojZdbh6EBEJ4ox/hHVbYOtKF3OYJ0BebSshyRkF8lPePGF7fQc4fnD5IckCXwTBmLQDRSEfST3Og6 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000003, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jul 30, 2024 at 01:43:35PM -0700, James Houghton wrote: > On Tue, Jul 30, 2024 at 1:03 PM David Hildenbrand wrote: > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index b100df8cb5857..1b1f40ff00b7d 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -2926,6 +2926,12 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd) > > return ptlock_ptr(page_ptdesc(pmd_page(*pmd))); > > } > > > > +static inline spinlock_t *ptep_lockptr(struct mm_struct *mm, pte_t *pte) > > +{ > > + BUILD_BUG_ON(IS_ENABLED(CONFIG_HIGHPTE)); > > + return ptlock_ptr(virt_to_ptdesc(pte)); > > Hi David, > > Small question: ptep_lockptr() does not handle the case where the size > of the PTE table is larger than PAGE_SIZE, but pmd_lockptr() does. > IIUC, for pte_lockptr() and ptep_lockptr() to return the same result > in this case, ptep_lockptr() should be doing the masking that > pmd_lockptr() is doing. Are you sure that you don't need to be doing > it? (Or maybe I am misunderstanding something.) I was just curious and looked at pte_alloc_one(), not too much archs implemented it besides the default (which calls pte_alloc_one_noprof(), and should be order=0 there). I didn't see any arch that actually allocated with non-zero orders. The motorola/m68k one is slightly involved, but still.. nothing I spot yet. Thanks, -- Peter Xu