From patchwork Fri Oct 21 16:36:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Houghton X-Patchwork-Id: 13015087 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 92D43C433FE for ; Fri, 21 Oct 2022 16:37:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 888A48E0015; Fri, 21 Oct 2022 12:37:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7730F8E0001; Fri, 21 Oct 2022 12:37:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 574E38E0015; Fri, 21 Oct 2022 12:37:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 40C988E0001 for ; Fri, 21 Oct 2022 12:37:35 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 20E561606B2 for ; Fri, 21 Oct 2022 16:37:35 +0000 (UTC) X-FDA: 80045512470.27.6158D76 Received: from mail-ua1-f73.google.com (mail-ua1-f73.google.com [209.85.222.73]) by imf22.hostedemail.com (Postfix) with ESMTP id BD1F8C001E for ; Fri, 21 Oct 2022 16:37:34 +0000 (UTC) Received: by mail-ua1-f73.google.com with SMTP id o17-20020a9f3311000000b003d01d091d4fso2355531uab.2 for ; Fri, 21 Oct 2022 09:37:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=CRJ6pkRKArtLmZe7XMBJjGLJyFbSk0rbbeye9q84C9k=; b=ZQtGwmeXsLEasfxlAVd+Ky+KcZ4u0ied8Nvno8abVpS+XKmDnGeaG7sbDC8DX8DjvM 74vP8xl/C/D6frwkZjH0NjGEaALQrxYOl4qyIHM6NFQ6TqBYFbfRh99+goV7aMS+wqHZ EWOers7WW52iKsOYpfLe1iauG6eIptFtQYmFfmKiotPdEPO4sKbu65xEzDbR/5RG82C/ y77vYpTF7YV+Whm4oAUX1QUUOJtL0b1RKIBN4O1mH8xMYkKU5aZVNAgTr4TGtpelYVZI e9gU8PeJNzs1B5TCPPy55btaAR0P5+I/VVVQLdPgY9hG0sq1HT32TKdmh24otsMY096+ x/yw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=CRJ6pkRKArtLmZe7XMBJjGLJyFbSk0rbbeye9q84C9k=; b=5VNEERqr6GcU5k1jL891F84tv/nl9VLS29cCFrl/cED74YknoL9Cceldl1Ty4gr1U0 yTzJSNsGDTNOLy1dXtdeB9M9dsLIUuwmJsyBSdoqhVRpy4Ad8Fvvv7hT+f37KMFc/xsg 3EXzMRwOvrwbgg81Jm0nxmk+S/H0W3eityZUYFZGDltt3am47w5GIgaMzUloHI0SBNaY xD1FUixATeBpgXRWFpRilWnqxpZ3xQnmhDMUoFMkWg99LHHzVFsZpgb2hNzC/njT241C cSm8e/zzZdekR80jlKbqtWjsDPTUNbNpqkhcRUCLtZ4DarLNjv+9mREPhHCJDPcD2AEr qXHA== X-Gm-Message-State: ACrzQf3DLhdt1W+8jSaxi6oZGGpyOtPLyyEJjUi38cTKSbyyIJ4OhWzH J6mppIFDWpWDAX1VLcjz8F3jKPLg4wdug22E X-Google-Smtp-Source: AMsMyM58r3yVRAL1NhZoJpcVLFGz0JqMpwGwsUiw6+Jq6Q4QwSneC2a182VZO4sfXGLadr38QjPrDD4kaXOFzTvM X-Received: from jthoughton.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2a4f]) (user=jthoughton job=sendgmr) by 2002:a05:6102:3678:b0:3a7:6056:9e7a with SMTP id bg24-20020a056102367800b003a760569e7amr12639659vsb.62.1666370254111; Fri, 21 Oct 2022 09:37:34 -0700 (PDT) Date: Fri, 21 Oct 2022 16:36:35 +0000 In-Reply-To: <20221021163703.3218176-1-jthoughton@google.com> Mime-Version: 1.0 References: <20221021163703.3218176-1-jthoughton@google.com> X-Mailer: git-send-email 2.38.0.135.g90850a2211-goog Message-ID: <20221021163703.3218176-20-jthoughton@google.com> Subject: [RFC PATCH v2 19/47] hugetlb: make hugetlb_follow_page_mask HGM-enabled From: James Houghton To: Mike Kravetz , Muchun Song , Peter Xu Cc: David Hildenbrand , David Rientjes , Axel Rasmussen , Mina Almasry , "Zach O'Keefe" , Manish Mishra , Naoya Horiguchi , "Dr . David Alan Gilbert" , "Matthew Wilcox (Oracle)" , Vlastimil Babka , Baolin Wang , Miaohe Lin , Yang Shi , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, James Houghton ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666370254; a=rsa-sha256; cv=none; b=Y0CGlIfSnXOrnNS0Ajsn4bGT0YOEkcoUglcvcTs+/cITL0Wya1/lPnZMN6L8LWVhLGXmHR ao+Sov7x33OMl5Ripbo/ePsyU+f7w9FlrDphxNDLUeSsASR7wXSs5jKBKS0LD/XKffsGke N9m7SxbbONzBQiuNDI4ebWU2hY7klMg= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=ZQtGwmeX; spf=pass (imf22.hostedemail.com: domain of 3zspSYwoKCM84E29F12E9819916z.x97638FI-775Gvx5.9C1@flex--jthoughton.bounces.google.com designates 209.85.222.73 as permitted sender) smtp.mailfrom=3zspSYwoKCM84E29F12E9819916z.x97638FI-775Gvx5.9C1@flex--jthoughton.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666370254; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=CRJ6pkRKArtLmZe7XMBJjGLJyFbSk0rbbeye9q84C9k=; b=BKIA99eLbt5NCz+iky8jRTp2YQUgx37rhaP1zYqtQhJeUmPlXqCnbJVCx3LvE8LmqpaXQC 3v5APy8UucSXRidss7Npn1EY4EPe3qy9OhAed81Q9LtYQ6k6RnfJFq7aCHdBD0jpALB8Tg uQLoFmOIwGwXP4Brv6Kyu2yPxvu4Afg= X-Stat-Signature: 5ocibj7jp9sfmnysrcixiro6dq3qtrij X-Rspamd-Queue-Id: BD1F8C001E Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=ZQtGwmeX; spf=pass (imf22.hostedemail.com: domain of 3zspSYwoKCM84E29F12E9819916z.x97638FI-775Gvx5.9C1@flex--jthoughton.bounces.google.com designates 209.85.222.73 as permitted sender) smtp.mailfrom=3zspSYwoKCM84E29F12E9819916z.x97638FI-775Gvx5.9C1@flex--jthoughton.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1666370254-387935 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: The change here is very simple: do a high-granularity walk. Signed-off-by: James Houghton --- mm/hugetlb.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d76ab32fb6d3..5783a8307a77 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6408,6 +6408,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, struct page *page = NULL; spinlock_t *ptl; pte_t *pte, entry; + struct hugetlb_pte hpte; /* * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via @@ -6429,9 +6430,22 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, return NULL; } - ptl = huge_pte_lock(h, mm, pte); +retry_walk: + hugetlb_pte_populate(&hpte, pte, huge_page_shift(h), + hpage_size_to_level(huge_page_size(h))); + hugetlb_hgm_walk(mm, vma, &hpte, address, + PAGE_SIZE, + /*stop_at_none=*/true); + + ptl = hugetlb_pte_lock(mm, &hpte); entry = huge_ptep_get(pte); if (pte_present(entry)) { + if (unlikely(!hugetlb_pte_present_leaf(&hpte, entry))) { + /* We raced with someone splitting from under us. */ + spin_unlock(ptl); + goto retry_walk; + } + page = pte_page(entry) + ((address & ~huge_page_mask(h)) >> PAGE_SHIFT); /*