From patchwork Mon May 27 21:01:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 13675779 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 A35B316191B; Mon, 27 May 2024 21:01:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716843704; cv=none; b=tc6MUZE7VUrt8/jqbJ8Jcn++xdRmJ0ZMjqI2CES08DMk/T91aapLN3AXj6d1P6zXvoq5PX3IvfPmpO9nbcyCJjW0craLhoU3ocK+ucYL71Dewhkfis1qgVGtJX+oG3cXkDPwm3NjCyp1g621hNho8ONAdyMrZv0ZSby5pOQbmVI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716843704; c=relaxed/simple; bh=d0tVjBIZ50XMn1Z2omCL0kJaG42f2EEBao3K7MDcvwo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=QyFrVJdt3Bk2dooQBHw4M658+Ns5xp5G+ur3Uc957OZN8YmwsiehCGvc3mPIPPsDUWc3JPP8jZJ3EQOYs77Q7FtPySwHilHgzgIPaOm7IOfnn6FZECmdd7XMyuKlmLdnaeJmYwO8r/Y6MtT4y5LFUSR+XSWS8FBVOX6b5IjMWAs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=XsuVjs01; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="XsuVjs01" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=HDLaoQD7cnvad9Y4kohJVJq8Wi/o15RfSw0EInJn85g=; b=XsuVjs01D2A4snvIOF0Tkf2krm Bd4zzZilKsucxO4d0BOVKcbaDAHrIdKrC/JQdKnTEZWBcLQe/jL2CmpPN5agCqjD8lfKIv3ilZs0v 0ZmkrbK8cmhLjJBoRa8kajFepFpRSjfrB5F68CezJOH4HNlVkbUKv0PaeYUOi7B2rA2W3ahfig8U2 0aC3Q35KhX4zT8Zy5RNW67HYbTMe3p8hh1+cYcVjiCHu8mud1r97EcMZCALq8Mp7BkUGpnEmnXEK6 Bw7dE+mGrKkk/Qj7GcnhQpb2qQiFIQyajYIblqZ2/a8+4hT90E46rkoMyQrEzzDf/TYszEv8N1GGy W3n+g2Lg==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sBhTJ-00000007zjV-12Yd; Mon, 27 May 2024 21:01:33 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org, willy@infradead.org, djwong@kernel.org, brauner@kernel.org, david@fromorbit.com, chandan.babu@oracle.com Cc: hare@suse.de, ritesh.list@gmail.com, john.g.garry@oracle.com, ziy@nvidia.com, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, gost.dev@samsung.com, p.raghav@samsung.com, kernel@pankajraghav.com, mcgrof@kernel.org Subject: [PATCH v5.1] fs: Allow fine-grained control of folio sizes Date: Mon, 27 May 2024 22:01:23 +0100 Message-ID: <20240527210125.1905586-1-willy@infradead.org> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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: Darrick J. Wong Reviewed-by: Hannes Reinecke --- For this version, I fixed the TODO that the maximum folio size was not being honoured. I made some other changes too like adding const, moving the location of the constants, checking CONFIG_TRANSPARENT_HUGEPAGE, and dropping some of the functions which aren't needed until later patches. (They can be added in the commits that need them). Also rebased against current Linus tree, so MAX_PAGECACHE_ORDER no longer needs to be moved). include/linux/pagemap.h | 81 +++++++++++++++++++++++++++++++++++------ mm/filemap.c | 6 +-- mm/readahead.c | 4 +- 3 files changed, 73 insertions(+), 18 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 1ed9274a0deb..c6aaceed0de6 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -204,13 +204,18 @@ 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_UNMOVABLE = 8, /* The mapping cannot be moved, ever */ + AS_FOLIO_ORDER_MIN = 16, + AS_FOLIO_ORDER_MAX = 21, /* Bits 16-25 are used for FOLIO_ORDER */ }; +#define AS_FOLIO_ORDER_MIN_MASK 0x001f0000 +#define AS_FOLIO_ORDER_MAX_MASK 0x03e00000 +#define AS_FOLIO_ORDER_MASK (AS_FOLIO_ORDER_MIN_MASK | AS_FOLIO_ORDER_MAX_MASK) + /** * mapping_set_error - record a writeback error in the address_space * @mapping: the mapping in which an error should be set @@ -359,9 +364,48 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) #define MAX_PAGECACHE_ORDER 8 #endif +/* + * 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) + min = MAX_PAGECACHE_ORDER; + if (max > 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 @@ -372,7 +416,23 @@ 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; } /* @@ -381,16 +441,13 @@ static inline void mapping_set_large_folios(struct address_space *mapping) */ static inline bool mapping_large_folio_support(struct address_space *mapping) { - 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 382c3d06bfb1..0557020f130e 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 c1b23989d9ca..66058ae02f2e 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -503,9 +503,9 @@ 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)); }