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 X-Spam-Level: X-Spam-Status: No, score=-20.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_RED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD9F4C4332D for ; Mon, 15 Mar 2021 17:49:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A56E864EED for ; Mon, 15 Mar 2021 17:49:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232196AbhCORtI (ORCPT ); Mon, 15 Mar 2021 13:49:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:44182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234935AbhCORsm (ORCPT ); Mon, 15 Mar 2021 13:48:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DC0B564F18; Mon, 15 Mar 2021 17:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1615830477; bh=x7//+Le+Sor0ocMyscy42am57iDVLnfkbDi0nbwJpOc=; h=Date:From:To:Subject:From; b=sB6IHrN7GpI5GLAbnImbX5QDXz2P8ZiDy2Zz6BEKIUEBt1oL2/hv2zdDVtPjRzXZ4 eBLz2a4jYpuHRVQuhP1rjwEDAGPKvlWSpVquSKKHF+fi/ROzGQPn/uWRNtSNKQrTAR 0bOjXPjpzyb58voYsYAxyoAV1WMrrRFYJyqubOVk= Date: Mon, 15 Mar 2021 10:47:56 -0700 From: akpm@linux-foundation.org To: aarcange@redhat.com, adobriyan@gmail.com, airlied@linux.ie, daniel@ffwll.ch, david@gibson.dropbear.id.au, galpress@amazon.com, hch@lst.de, jack@suse.cz, jannh@google.com, jgg@ziepe.ca, kirill@shutemov.name, ktkhai@virtuozzo.com, linmiaohe@huawei.com, linux-graphics-maintainer@vmware.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, peterx@redhat.com, rppt@linux.vnet.ibm.com, sroland@vmware.com, willy@infradead.org, wzam@amazon.com Subject: [merged] hugetlb-dedup-the-code-to-add-a-new-file_region.patch removed from -mm tree Message-ID: <20210315174756.Xf6t5eCY8%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: hugetlb: dedup the code to add a new file_region has been removed from the -mm tree. Its filename was hugetlb-dedup-the-code-to-add-a-new-file_region.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Peter Xu Subject: hugetlb: dedup the code to add a new file_region Patch series "mm/hugetlb: Early cow on fork, and a few cleanups", v5. As reported by Gal [1], we still miss the code clip to handle early cow for hugetlb case, which is true. Again, it still feels odd to fork() after using a few huge pages, especially if they're privately mapped to me.. However I do agree with Gal and Jason in that we should still have that since that'll complete the early cow on fork effort at least, and it'll still fix issues where buffers are not well under control and not easy to apply MADV_DONTFORK. The first two patches (1-2) are some cleanups I noticed when reading into the hugetlb reserve map code. I think it's good to have but they're not necessary for fixing the fork issue. The last two patches (3-4) are the real fix. I tested this with a fork() after some vfio-pci assignment, so I'm pretty sure the page copy path could trigger well (page will be accounted right after the fork()), but I didn't do data check since the card I assigned is some random nic. https://github.com/xzpeter/linux/tree/fork-cow-pin-huge [1] https://lore.kernel.org/lkml/27564187-4a08-f187-5a84-3df50009f6ca@amazon.com/ Introduce hugetlb_resv_map_add() helper to add a new file_region rather than duplication the similar code twice in add_reservation_in_range(). Link: https://lkml.kernel.org/r/20210217233547.93892-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20210217233547.93892-2-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Mike Kravetz Reviewed-by: Miaohe Lin Cc: Gal Pressman Cc: Matthew Wilcox Cc: Wei Zhang Cc: Mike Rapoport Cc: Christoph Hellwig Cc: David Gibson Cc: Jason Gunthorpe Cc: Jann Horn Cc: Kirill Tkhai Cc: Kirill Shutemov Cc: Andrea Arcangeli Cc: Jan Kara Cc: Alexey Dobriyan Cc: Daniel Vetter Cc: David Airlie Cc: Roland Scheidegger Cc: VMware Graphics Signed-off-by: Andrew Morton --- mm/hugetlb.c | 51 +++++++++++++++++++++++++------------------------ 1 file changed, 27 insertions(+), 24 deletions(-) --- a/mm/hugetlb.c~hugetlb-dedup-the-code-to-add-a-new-file_region +++ a/mm/hugetlb.c @@ -331,6 +331,24 @@ static void coalesce_file_region(struct } } +static inline long +hugetlb_resv_map_add(struct resv_map *map, struct file_region *rg, long from, + long to, struct hstate *h, struct hugetlb_cgroup *cg, + long *regions_needed) +{ + struct file_region *nrg; + + if (!regions_needed) { + nrg = get_file_region_entry_from_cache(map, from, to); + record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); + list_add(&nrg->link, rg->link.prev); + coalesce_file_region(map, nrg); + } else + *regions_needed += 1; + + return to - from; +} + /* * Must be called with resv->lock held. * @@ -346,7 +364,7 @@ static long add_reservation_in_range(str long add = 0; struct list_head *head = &resv->regions; long last_accounted_offset = f; - struct file_region *rg = NULL, *trg = NULL, *nrg = NULL; + struct file_region *rg = NULL, *trg = NULL; if (regions_needed) *regions_needed = 0; @@ -375,18 +393,11 @@ static long add_reservation_in_range(str /* Add an entry for last_accounted_offset -> rg->from, and * update last_accounted_offset. */ - if (rg->from > last_accounted_offset) { - add += rg->from - last_accounted_offset; - if (!regions_needed) { - nrg = get_file_region_entry_from_cache( - resv, last_accounted_offset, rg->from); - record_hugetlb_cgroup_uncharge_info(h_cg, h, - resv, nrg); - list_add(&nrg->link, rg->link.prev); - coalesce_file_region(resv, nrg); - } else - *regions_needed += 1; - } + if (rg->from > last_accounted_offset) + add += hugetlb_resv_map_add(resv, rg, + last_accounted_offset, + rg->from, h, h_cg, + regions_needed); last_accounted_offset = rg->to; } @@ -394,17 +405,9 @@ static long add_reservation_in_range(str /* Handle the case where our range extends beyond * last_accounted_offset. */ - if (last_accounted_offset < t) { - add += t - last_accounted_offset; - if (!regions_needed) { - nrg = get_file_region_entry_from_cache( - resv, last_accounted_offset, t); - record_hugetlb_cgroup_uncharge_info(h_cg, h, resv, nrg); - list_add(&nrg->link, rg->link.prev); - coalesce_file_region(resv, nrg); - } else - *regions_needed += 1; - } + if (last_accounted_offset < t) + add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, + t, h, h_cg, regions_needed); VM_BUG_ON(add < 0); return add; _ Patches currently in -mm which might be from peterx@redhat.com are hugetlb-pass-vma-into-huge_pte_alloc-and-huge_pmd_share.patch hugetlb-pass-vma-into-huge_pte_alloc-and-huge_pmd_share-fix.patch hugetlb-userfaultfd-forbid-huge-pmd-sharing-when-uffd-enabled.patch hugetlb-userfaultfd-forbid-huge-pmd-sharing-when-uffd-enabled-fix.patch mm-hugetlb-move-flush_hugetlb_tlb_range-into-hugetlbh.patch hugetlb-userfaultfd-unshare-all-pmds-for-hugetlbfs-when-register-wp.patch userfaultfd-selftests-use-user-mode-only.patch userfaultfd-selftests-remove-the-time-check-on-delayed-uffd.patch userfaultfd-selftests-dropping-verify-check-in-locking_thread.patch userfaultfd-selftests-only-dump-counts-if-mode-enabled.patch userfaultfd-selftests-unify-error-handling.patch