From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1F0D717C7CE for ; Tue, 5 Nov 2024 16:37:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730824671; cv=none; b=q8Cp6hHa1/PeWlr8BsozOyFCgkLWVKb6ypagbu2sdyKMMzO5osuJRUw3N2lutTgx4y2oak80DInVLar9Nm7aDI0/lx3zt++FPkXmvb5zTkx+vZiJ1LCmu045HhTzzwv3Y9I7FZDklfNbn+6MSol16bQAPBYHn3L33ZpbRTtNNhU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730824671; c=relaxed/simple; bh=tkNABRAnUSJHDOsH6KR9qu5hhsSYQ898jeL2mWKRexg=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=LKaVZvgaMQN8RyTzdOYfE620ByDmlOFu0PWe6UkP2dACKAr/HJ56Dz6SyD4jGZMKYVn24QeEmtVXP9ldWyY/2I4+N2/DNFocWBhIFJQtvj1x0uIGanh1emzYz7Fqqa/Rl/Bl/ZVtHjm2eHXdBiBNAQ4sDO+aTJ2/QREm/Q0ziXc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tpH+KaHO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="tpH+KaHO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52E29C4CECF; Tue, 5 Nov 2024 16:37:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730824670; bh=tkNABRAnUSJHDOsH6KR9qu5hhsSYQ898jeL2mWKRexg=; h=Subject:To:Cc:From:Date:From; b=tpH+KaHOWrOJRnVWZBK/ViNe7FTbOjxq3X4AysDRPsjxmHgpRz2crLn6IEMduxhvk oMjt/d6BmMfLokrKaa+Ma/L57oWYANbNabpgTGbXjCtR/ATKOnfcrLo/YQQ7TLSELd LMqHwg0iHO98PiOBJpPTWLAxVBgyvJHbGNH5Cf9s= Subject: FAILED: patch "[PATCH] mm: allow set/clear page_type again" failed to apply to 6.6-stable tree To: yuzhao@google.com,akpm@linux-foundation.org,muchun.song@linux.dev,stable@vger.kernel.org,willy@infradead.org Cc: From: Date: Tue, 05 Nov 2024 17:37:25 +0100 Message-ID: <2024110524-patience-rice-79e2@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 9d08ec41a0645283d79a2e642205d488feaceacf # git commit -s git send-email --to '' --in-reply-to '2024110524-patience-rice-79e2@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9d08ec41a0645283d79a2e642205d488feaceacf Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Sat, 19 Oct 2024 22:22:12 -0600 Subject: [PATCH] mm: allow set/clear page_type again Some page flags (page->flags) were converted to page types (page->page_types). A recent example is PG_hugetlb. >From the exclusive writer's perspective, e.g., a thread doing __folio_set_hugetlb(), there is a difference between the page flag and type APIs: the former allows the same non-atomic operation to be repeated whereas the latter does not. For example, calling __folio_set_hugetlb() twice triggers VM_BUG_ON_FOLIO(), since the second call expects the type (PG_hugetlb) not to be set previously. Using add_hugetlb_folio() as an example, it calls __folio_set_hugetlb() in the following error-handling path. And when that happens, it triggers the aforementioned VM_BUG_ON_FOLIO(). if (folio_test_hugetlb(folio)) { rc = hugetlb_vmemmap_restore_folio(h, folio); if (rc) { spin_lock_irq(&hugetlb_lock); add_hugetlb_folio(h, folio, false); ... It is possible to make hugeTLB comply with the new requirements from the page type API. However, a straightforward fix would be to just allow the same page type to be set or cleared again inside the API, to avoid any changes to its callers. Link: https://lkml.kernel.org/r/20241020042212.296781-1-yuzhao@google.com Fixes: d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") Signed-off-by: Yu Zhao Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Signed-off-by: Andrew Morton diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 1b3a76710487..cc839e4365c1 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -975,12 +975,16 @@ static __always_inline bool folio_test_##fname(const struct folio *folio) \ } \ static __always_inline void __folio_set_##fname(struct folio *folio) \ { \ + if (folio_test_##fname(folio)) \ + return; \ VM_BUG_ON_FOLIO(data_race(folio->page.page_type) != UINT_MAX, \ folio); \ folio->page.page_type = (unsigned int)PGTY_##lname << 24; \ } \ static __always_inline void __folio_clear_##fname(struct folio *folio) \ { \ + if (folio->page.page_type == UINT_MAX) \ + return; \ VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \ folio->page.page_type = UINT_MAX; \ } @@ -993,11 +997,15 @@ static __always_inline int Page##uname(const struct page *page) \ } \ static __always_inline void __SetPage##uname(struct page *page) \ { \ + if (Page##uname(page)) \ + return; \ VM_BUG_ON_PAGE(data_race(page->page_type) != UINT_MAX, page); \ page->page_type = (unsigned int)PGTY_##lname << 24; \ } \ static __always_inline void __ClearPage##uname(struct page *page) \ { \ + if (page->page_type == UINT_MAX) \ + return; \ VM_BUG_ON_PAGE(!Page##uname(page), page); \ page->page_type = UINT_MAX; \ }