From patchwork Mon Jul 15 09:44:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pankaj Raghav (Samsung)" X-Patchwork-Id: 13733218 Received: from mout-p-103.mailbox.org (mout-p-103.mailbox.org [80.241.56.161]) (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 E149617C7D5; Mon, 15 Jul 2024 09:53:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.161 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721037239; cv=none; b=K55oPtHNygzyIyyj0iXYyWyjR2bIZsRmJZnCU1GjSXkcFZCIlbFbc1Yn1eSrXhffgGAy5BmQQRCYYQnRiSyLBjqJAAf0tNU1ExSdUveaYomTlUWaA5+t0tOOaC8dN6d6UJN6ifuvvkGvx+MDZ8BUmjtO6dUSKTy+3/P00vZW+sg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721037239; c=relaxed/simple; bh=tH1qoA+v7Er8l4BtBWAJFrPy9YxStNo7y1QfBIifWJU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lnuBcUUoVWGSXwHEEL/yjduNkwsIuPghDHdRgOWgc/0eLFJyQbS/m/C+6fUXxP2mRz4FYvEVaeT97ZfHQQl/BdWy37RKNou82TA/PWxaUPXCGGDpCb/mgchVuiDq1vOk+JGnKFgUa+j8OlXc9h0uEKlzdnV8DTebe9JbqtStbHs= 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=RVLnDS+N; arc=none smtp.client-ip=80.241.56.161 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="RVLnDS+N" Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:b231:465::1]) (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-103.mailbox.org (Postfix) with ESMTPS id 4WMy3s3l5Jz9sS2; Mon, 15 Jul 2024 11:45:13 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1721036713; 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=iVeOVLNn5PKvSoACNvjh+SwYtpf2/QUWqFh2OAeof8s=; b=RVLnDS+N6kgzLaAN2r/msOIlhnogkVXm7MiGpKj1WBRUh+hwZrEMC2ZAiKPLVbQphJt7h6 zL7X5ZwbMIWvImMkXGhYPh5fxhHue1l29Mf8XoUinLxSxc5DBVxdcqt7zeg1jRbjx1si5+ xAMhuT5CzuqZ6gXHrXe8OvI/GpgvPduOnO8c7nGnMcuAgpYpSjjat3CSUQM3fRYJJWtNuI f0u7PfopX3cC2MS+mxBzgxgdBt7uxtWcW89WKCLYDTi5af2e9LpP+CrXAfrIz2hk6VpTen /vRBrCFrzXX15aO9Dpa6ESEq6fkpDD90CHUtvW9TLDRJrxeB4ivMKTGoa2qyqw== From: "Pankaj Raghav (Samsung)" To: david@fromorbit.com, willy@infradead.org, chandan.babu@oracle.com, djwong@kernel.org, brauner@kernel.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, yang@os.amperecomputing.com, linux-mm@kvack.org, john.g.garry@oracle.com, linux-fsdevel@vger.kernel.org, hare@suse.de, p.raghav@samsung.com, mcgrof@kernel.org, gost.dev@samsung.com, cl@os.amperecomputing.com, linux-xfs@vger.kernel.org, kernel@pankajraghav.com, ryan.roberts@arm.com, hch@lst.de, Zi Yan Subject: [PATCH v10 01/10] fs: Allow fine-grained control of folio sizes Date: Mon, 15 Jul 2024 11:44:48 +0200 Message-ID: <20240715094457.452836-2-kernel@pankajraghav.com> In-Reply-To: <20240715094457.452836-1-kernel@pankajraghav.com> References: <20240715094457.452836-1-kernel@pankajraghav.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 4WMy3s3l5Jz9sS2 From: "Matthew Wilcox (Oracle)" We need filesystems to be able to communicate acceptable folio sizes to the pagecache for a variety of uses (e.g. large block sizes). Support a range of folio sizes between order-0 and order-31. Signed-off-by: Matthew Wilcox (Oracle) Co-developed-by: Pankaj Raghav Signed-off-by: Pankaj Raghav Reviewed-by: Hannes Reinecke Reviewed-by: Darrick J. Wong --- include/linux/pagemap.h | 107 +++++++++++++++++++++++++++++++++++----- mm/filemap.c | 6 +-- mm/readahead.c | 4 +- 3 files changed, 98 insertions(+), 19 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 8026a8a433d36..8d2b5c51461b0 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -204,14 +204,21 @@ enum mapping_flags { AS_EXITING = 4, /* final truncate in progress */ /* writeback related tags are not used */ AS_NO_WRITEBACK_TAGS = 5, - AS_LARGE_FOLIO_SUPPORT = 6, - AS_RELEASE_ALWAYS, /* Call ->release_folio(), even if no private data */ - AS_STABLE_WRITES, /* must wait for writeback before modifying + AS_RELEASE_ALWAYS = 6, /* Call ->release_folio(), even if no private data */ + AS_STABLE_WRITES = 7, /* must wait for writeback before modifying folio contents */ - AS_UNMOVABLE, /* The mapping cannot be moved, ever */ - AS_INACCESSIBLE, /* Do not attempt direct R/W access to the mapping */ + AS_UNMOVABLE = 8, /* The mapping cannot be moved, ever */ + AS_INACCESSIBLE = 9, /* Do not attempt direct R/W access to the mapping */ + /* Bits 16-25 are used for FOLIO_ORDER */ + AS_FOLIO_ORDER_BITS = 5, + AS_FOLIO_ORDER_MIN = 16, + AS_FOLIO_ORDER_MAX = AS_FOLIO_ORDER_MIN + AS_FOLIO_ORDER_BITS, }; +#define AS_FOLIO_ORDER_MASK ((1u << AS_FOLIO_ORDER_BITS) - 1) +#define AS_FOLIO_ORDER_MIN_MASK (AS_FOLIO_ORDER_MASK << AS_FOLIO_ORDER_MIN) +#define AS_FOLIO_ORDER_MAX_MASK (AS_FOLIO_ORDER_MASK << AS_FOLIO_ORDER_MAX) + /** * mapping_set_error - record a writeback error in the address_space * @mapping: the mapping in which an error should be set @@ -367,9 +374,70 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) #define MAX_XAS_ORDER (XA_CHUNK_SHIFT * 2 - 1) #define MAX_PAGECACHE_ORDER min(MAX_XAS_ORDER, PREFERRED_MAX_PAGECACHE_ORDER) +/* + * mapping_max_folio_size_supported() - Check the max folio size supported + * + * The filesystem should call this function at mount time if there is a + * requirement on the folio mapping size in the page cache. + */ +static inline size_t mapping_max_folio_size_supported(void) +{ + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return 1U << (PAGE_SHIFT + MAX_PAGECACHE_ORDER); + return PAGE_SIZE; +} + +/* + * mapping_set_folio_order_range() - Set the orders supported by a file. + * @mapping: The address space of the file. + * @min: Minimum folio order (between 0-MAX_PAGECACHE_ORDER inclusive). + * @max: Maximum folio order (between @min-MAX_PAGECACHE_ORDER inclusive). + * + * The filesystem should call this function in its inode constructor to + * indicate which base size (min) and maximum size (max) of folio the VFS + * can use to cache the contents of the file. This should only be used + * if the filesystem needs special handling of folio sizes (ie there is + * something the core cannot know). + * Do not tune it based on, eg, i_size. + * + * Context: This should not be called while the inode is active as it + * is non-atomic. + */ +static inline void mapping_set_folio_order_range(struct address_space *mapping, + unsigned int min, + unsigned int max) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return; + + if (min > MAX_PAGECACHE_ORDER) { + VM_WARN_ONCE(1, + "min order > MAX_PAGECACHE_ORDER. Setting min_order to MAX_PAGECACHE_ORDER"); + min = MAX_PAGECACHE_ORDER; + } + + if (max > MAX_PAGECACHE_ORDER) { + VM_WARN_ONCE(1, + "max order > MAX_PAGECACHE_ORDER. Setting max_order to MAX_PAGECACHE_ORDER"); + max = MAX_PAGECACHE_ORDER; + } + + if (max < min) + max = min; + + mapping->flags = (mapping->flags & ~AS_FOLIO_ORDER_MASK) | + (min << AS_FOLIO_ORDER_MIN) | (max << AS_FOLIO_ORDER_MAX); +} + +static inline void mapping_set_folio_min_order(struct address_space *mapping, + unsigned int min) +{ + mapping_set_folio_order_range(mapping, min, MAX_PAGECACHE_ORDER); +} + /** * mapping_set_large_folios() - Indicate the file supports large folios. - * @mapping: The file. + * @mapping: The address space of the file. * * The filesystem should call this function in its inode constructor to * indicate that the VFS can use large folios to cache the contents of @@ -380,7 +448,23 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) */ static inline void mapping_set_large_folios(struct address_space *mapping) { - __set_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); + mapping_set_folio_order_range(mapping, 0, MAX_PAGECACHE_ORDER); +} + +static inline unsigned int +mapping_max_folio_order(const struct address_space *mapping) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return 0; + return (mapping->flags & AS_FOLIO_ORDER_MAX_MASK) >> AS_FOLIO_ORDER_MAX; +} + +static inline unsigned int +mapping_min_folio_order(const struct address_space *mapping) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return 0; + return (mapping->flags & AS_FOLIO_ORDER_MIN_MASK) >> AS_FOLIO_ORDER_MIN; } /* @@ -393,16 +477,13 @@ static inline bool mapping_large_folio_support(struct address_space *mapping) VM_WARN_ONCE((unsigned long)mapping & PAGE_MAPPING_ANON, "Anonymous mapping always supports large folio"); - return IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && - test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); + return mapping_max_folio_order(mapping) > 0; } /* Return the maximum folio size for this pagecache mapping, in bytes. */ -static inline size_t mapping_max_folio_size(struct address_space *mapping) +static inline size_t mapping_max_folio_size(const struct address_space *mapping) { - if (mapping_large_folio_support(mapping)) - return PAGE_SIZE << MAX_PAGECACHE_ORDER; - return PAGE_SIZE; + return PAGE_SIZE << mapping_max_folio_order(mapping); } static inline int filemap_nr_thps(struct address_space *mapping) diff --git a/mm/filemap.c b/mm/filemap.c index d62150418b910..ad5e4a848070e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1933,10 +1933,8 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, if (WARN_ON_ONCE(!(fgp_flags & (FGP_LOCK | FGP_FOR_MMAP)))) fgp_flags |= FGP_LOCK; - if (!mapping_large_folio_support(mapping)) - order = 0; - if (order > MAX_PAGECACHE_ORDER) - order = MAX_PAGECACHE_ORDER; + if (order > mapping_max_folio_order(mapping)) + order = mapping_max_folio_order(mapping); /* If we're not aligned, allocate a smaller folio */ if (index & ((1UL << order) - 1)) order = __ffs(index); diff --git a/mm/readahead.c b/mm/readahead.c index 517c0be7ce665..3e5239e9e1777 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -449,10 +449,10 @@ void page_cache_ra_order(struct readahead_control *ractl, limit = min(limit, index + ra->size - 1); - if (new_order < MAX_PAGECACHE_ORDER) + if (new_order < mapping_max_folio_order(mapping)) new_order += 2; - new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order); + new_order = min(mapping_max_folio_order(mapping), new_order); new_order = min_t(unsigned int, new_order, ilog2(ra->size)); /* See comment in page_cache_ra_unbounded() */