From patchwork Wed Jan 10 09:21:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13515850 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2E2CB3EA8A; Wed, 10 Jan 2024 09:21:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VvT59FfZ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=vemtm26RZJwq2BkJen0DsgudNpnNIQOHTlEDhkpMTMQ=; b=VvT59FfZyGViQ4E9bybilVlr/n E58xcBMqiG7yHbZRyzY+MeZqOUO73LE+/oyqen6J0wutWRO0UD5OylhJ4Mqx1GoUwrpWkQ9ockMTO zyTTGC4l3K2AVsMneNh/767/v9arpPkmZu6jv9Kpv6xyiCQwY2IKXC2f87wwmXRPgcGR0L6ncNvtJ bRz65LMjl5Yq3e1j5b56u9hCiLVBySWQ/Sr/aid4EvqC/7O7zhvFA590kdpkdOalJHAgkUUs+n+Vw EHaNxwv8+03GiryNOsM8jEJ2KcP9yx6govhS285icE+S4S6N7L/QIGjZIj5ny8VRfIkY7q9yV3/yB MgyUdYOw==; Received: from [2001:4bb8:191:2f6b:27f:45ef:e74a:3466] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1rNUlv-00AsAi-1t; Wed, 10 Jan 2024 09:21:16 +0000 From: Christoph Hellwig To: Matthew Wilcox , Hugh Dickins , Chandan Babu R Cc: "Darrick J . Wong" , Andrew Morton , David Howells , Jarkko Sakkinen , Dave Hansen , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Christian Koenig , Huang Rui , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, x86@kernel.org, linux-sgx@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, keyrings@vger.kernel.org Subject: [PATCH 1/2] mm: add a mapping_clear_large_folios helper Date: Wed, 10 Jan 2024 10:21:08 +0100 Message-Id: <20240110092109.1950011-2-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240110092109.1950011-1-hch@lst.de> References: <20240110092109.1950011-1-hch@lst.de> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Users of shmem_kernel_file_setup might not be able to deal with large folios (yet). Give them a way to disable large folio support on their mapping. Signed-off-by: Christoph Hellwig --- include/linux/pagemap.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 06142ff7f9ce0e..352d1f8423292c 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -343,6 +343,20 @@ static inline void mapping_set_large_folios(struct address_space *mapping) __set_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); } +/** + * mapping_clear_large_folios() - Disable large folio support for a mapping + * @mapping: The mapping. + * + * This can be called to undo the effect of mapping_set_large_folios(). + * + * Context: This should not be called while the inode is active as it + * is non-atomic. + */ +static inline void mapping_clear_large_folios(struct address_space *mapping) +{ + __clear_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); +} + /* * Large folio support currently depends on THP. These dependencies are * being worked on but are not yet fixed.