From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) (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 DDDD22E8E00; Thu, 24 Jul 2025 14:50:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753368643; cv=none; b=Xwcpj/XamDFit4sJlyBSDVrm0FQaWDIZzmSTqrO84436gRqih4myWYvxqrl77UC87Gzdtcf0K4FSTNMi+ZmmG4mDnwf/lJrRWaBcf4fnZxE1gbQvG08VNOs+HMKka61pIhmDp0Rq6fsstjPavD6kAGJgunsVvbfDdIsvtekFy9A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753368643; c=relaxed/simple; bh=3yvTRW5FhiAKs+vOBuG4HDRUaaXxURgqxp/7gqTmM9g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u99tfd1Qf/aYV/qi6ZfDisaoN9/l4AwyVFOjTroTthc/B+6W4t8snS/yIjBv8Ey0kfng4jw09oPd2uI7QcdXTNqcQXRjMT+gkUnBuC+gjgWrj/PDaLwfxspXEqcbo8wn8qE7/hWtPkbRdx8M+YQxLimJ0M/YDi9oiHLmN905DuA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pankajraghav.com; spf=pass smtp.mailfrom=pankajraghav.com; dkim=pass (2048-bit key) header.d=pankajraghav.com header.i=@pankajraghav.com header.b=bmODlJne; arc=none smtp.client-ip=80.241.56.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pankajraghav.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pankajraghav.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pankajraghav.com header.i=@pankajraghav.com header.b="bmODlJne" Received: from smtp102.mailbox.org (smtp102.mailbox.org [IPv6:2001:67c:2050:b231:465::102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4bnv7f3dscz9stm; Thu, 24 Jul 2025 16:50:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1753368638; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kgGhybuB+tAZvqsghR5tZCuaExpLC7iQdGM6Ue4YApc=; b=bmODlJnet//564H9GeC9UKYZRU0b9X8jENtT/ImDqDE/BSUhU8rDT7sLaQXjai9cqvVPzC XRTh5RmBQ1OSw7iUsTEHZpj07zzID1a8hden/+Ko29ENEAmGxnE9WXBP/ZCpE6TdMcVWFY ziPtCk32ubRHQP9Re7bDQ5LcoGHYZ1HRESsfNTQRdlI7cFMrm5aCsx6seEQ8RRP0sUdfvl sEIV5w7JLjAF4BSoGp8kJuKfvhw5slZnmYfIQJcNvK1EQx3HCXMNi0n23ze48W2IQslE6a asi3QmBg3iL+GjW4H1HswQbOAienOX5tDKRH0fN+Qa6qnvMZ7lHZs/hA3JtlHw== Authentication-Results: outgoing_mbo_mout; dkim=none; spf=pass (outgoing_mbo_mout: domain of kernel@pankajraghav.com designates 2001:67c:2050:b231:465::102 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com From: "Pankaj Raghav (Samsung)" To: Suren Baghdasaryan , Ryan Roberts , Baolin Wang , Borislav Petkov , Ingo Molnar , "H . Peter Anvin" , Vlastimil Babka , Zi Yan , Mike Rapoport , Dave Hansen , Michal Hocko , David Hildenbrand , Lorenzo Stoakes , Andrew Morton , Thomas Gleixner , Nico Pache , Dev Jain , "Liam R . Howlett" , Jens Axboe Cc: linux-kernel@vger.kernel.org, willy@infradead.org, linux-mm@kvack.org, x86@kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Darrick J . Wong" , mcgrof@kernel.org, gost.dev@samsung.com, kernel@pankajraghav.com, hch@lst.de, Pankaj Raghav Subject: [RFC v2 3/4] mm: add largest_zero_folio() routine Date: Thu, 24 Jul 2025 16:50:00 +0200 Message-ID: <20250724145001.487878-4-kernel@pankajraghav.com> In-Reply-To: <20250724145001.487878-1-kernel@pankajraghav.com> References: <20250724145001.487878-1-kernel@pankajraghav.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4bnv7f3dscz9stm From: Pankaj Raghav Add largest_zero_folio() routine so that huge_zero_folio can be used directly when CONFIG_STATIC_HUGE_ZERO_FOLIO is enabled. This will return ZERO_PAGE folio if CONFIG_STATIC_HUGE_ZERO_FOLIO is disabled or if we failed to allocate a huge_zero_folio. Co-developed-by: David Hildenbrand Signed-off-by: David Hildenbrand Signed-off-by: Pankaj Raghav --- include/linux/huge_mm.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 78ebceb61d0e..c44a6736704b 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -716,4 +716,21 @@ static inline int split_folio_to_order(struct folio *folio, int new_order) return split_folio_to_list_to_order(folio, NULL, new_order); } +/* + * largest_zero_folio - Get the largest zero size folio available + * + * This function will return huge_zero_folio if CONFIG_STATIC_HUGE_ZERO_FOLIO + * is enabled. Otherwise, a ZERO_PAGE folio is returned. + * + * Deduce the size of the folio with folio_size instead of assuming the + * folio size. + */ +static inline struct folio *largest_zero_folio(void) +{ + struct folio *folio = get_static_huge_zero_folio(); + + if (folio) + return folio; + return page_folio(ZERO_PAGE(0)); +} #endif /* _LINUX_HUGE_MM_H */ -- 2.49.0