From: Dave Hansen <dave@sr71.net>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Hugh Dickins <hughd@google.com>,
Wu Fengguang <fengguang.wu@intel.com>, Jan Kara <jack@suse.cz>,
Mel Gorman <mgorman@suse.de>,
linux-mm@kvack.org, Andi Kleen <ak@linux.intel.com>,
Matthew Wilcox <matthew.r.wilcox@intel.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Hillf Danton <dhillf@gmail.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv4 04/39] radix-tree: implement preload for multiple contiguous elements
Date: Tue, 21 May 2013 11:58:06 -0700 [thread overview]
Message-ID: <519BC3BE.3070702@sr71.net> (raw)
In-Reply-To: <1368321816-17719-5-git-send-email-kirill.shutemov@linux.intel.com>
On 05/11/2013 06:23 PM, Kirill A. Shutemov wrote:
> Currently radix_tree_preload() only guarantees enough nodes to insert
> one element. It's a hard limit. For transparent huge page cache we want
> to insert HPAGE_PMD_NR (512 on x86-64) entires to address_space at once.
^^entries
> This patch introduces radix_tree_preload_count(). It allows to
> preallocate nodes enough to insert a number of *contiguous* elements.
Would radix_tree_preload_contig() be a better name, then?
...
> On 64-bit system:
> For RADIX_TREE_MAP_SHIFT=3, old array size is 43, new is 107.
> For RADIX_TREE_MAP_SHIFT=4, old array size is 31, new is 63.
> For RADIX_TREE_MAP_SHIFT=6, old array size is 21, new is 30.
>
> On 32-bit system:
> For RADIX_TREE_MAP_SHIFT=3, old array size is 21, new is 84.
> For RADIX_TREE_MAP_SHIFT=4, old array size is 15, new is 46.
> For RADIX_TREE_MAP_SHIFT=6, old array size is 11, new is 19.
>
> On most machines we will have RADIX_TREE_MAP_SHIFT=6.
Thanks for adding that to the description. The array you're talking
about is just pointers, right?
107-43 = 64. So, we have 64 extra pointers * NR_CPUS, plus 64 extra
radix tree nodes that we will keep around most of the time. On x86_64,
that's 512 bytes plus 64*560 bytes of nodes which is ~35k of memory per CPU.
That's not bad I guess, but I do bet it's something that some folks want
to configure out. Please make sure to call out the actual size cost in
bytes per CPU in future patch postings, at least for the common case
(64-bit non-CONFIG_BASE_SMALL).
> Since only THP uses batched preload at the , we disable (set max preload
> to 1) it if !CONFIG_TRANSPARENT_HUGEPAGE_PAGECACHE. This can be changed
> in the future.
"at the..." Is there something missing in that sentence?
No major nits, so:
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
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next prev parent reply other threads:[~2013-05-21 18:58 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-12 1:22 [PATCHv4 00/39] Transparent huge page cache Kirill A. Shutemov
2013-05-12 1:22 ` [PATCHv4 01/39] mm: drop actor argument of do_generic_file_read() Kirill A. Shutemov
2013-05-21 18:22 ` Dave Hansen
2013-05-12 1:22 ` [PATCHv4 02/39] block: implement add_bdi_stat() Kirill A. Shutemov
2013-05-21 18:25 ` Dave Hansen
2013-05-22 11:06 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 03/39] mm: implement zero_huge_user_segment and friends Kirill A. Shutemov
2013-05-23 10:32 ` Hillf Danton
2013-05-23 11:32 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 04/39] radix-tree: implement preload for multiple contiguous elements Kirill A. Shutemov
2013-05-21 18:58 ` Dave Hansen [this message]
2013-05-22 12:03 ` Kirill A. Shutemov
2013-05-22 14:20 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 05/39] memcg, thp: charge huge cache pages Kirill A. Shutemov
2013-05-21 19:04 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 06/39] thp, mm: avoid PageUnevictable on active/inactive lru lists Kirill A. Shutemov
2013-05-21 19:17 ` Dave Hansen
2013-05-22 12:34 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 07/39] thp, mm: basic defines for transparent huge page cache Kirill A. Shutemov
2013-05-23 10:36 ` Hillf Danton
2013-05-23 15:49 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 08/39] thp: compile-time and sysfs knob for thp pagecache Kirill A. Shutemov
2013-05-22 11:19 ` Hillf Danton
2013-05-12 1:23 ` [PATCHv4 09/39] thp, mm: introduce mapping_can_have_hugepages() predicate Kirill A. Shutemov
2013-05-21 19:28 ` Dave Hansen
2013-05-22 13:51 ` Kirill A. Shutemov
2013-05-22 15:31 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 10/39] thp: account anon transparent huge pages into NR_ANON_PAGES Kirill A. Shutemov
2013-05-21 19:32 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 11/39] thp: represent file thp pages in meminfo and friends Kirill A. Shutemov
2013-05-21 19:34 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 12/39] thp, mm: rewrite add_to_page_cache_locked() to support huge pages Kirill A. Shutemov
2013-05-21 19:59 ` Dave Hansen
2013-05-23 14:36 ` Kirill A. Shutemov
2013-05-23 16:00 ` Dave Hansen
2013-05-28 11:59 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 13/39] mm: trace filemap: dump page order Kirill A. Shutemov
2013-05-21 19:35 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 14/39] thp, mm: rewrite delete_from_page_cache() to support huge pages Kirill A. Shutemov
2013-05-21 20:14 ` Dave Hansen
2013-05-28 12:28 ` Kirill A. Shutemov
2013-06-07 15:10 ` Kirill A. Shutemov
2013-06-07 15:56 ` Dave Hansen
2013-06-10 17:41 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 15/39] thp, mm: trigger bug in replace_page_cache_page() on THP Kirill A. Shutemov
2013-05-21 20:17 ` Dave Hansen
2013-05-28 12:53 ` Kirill A. Shutemov
2013-05-28 16:33 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 16/39] thp, mm: locking tail page is a bug Kirill A. Shutemov
2013-05-21 20:18 ` Dave Hansen
2013-05-22 14:12 ` Kirill A. Shutemov
2013-05-22 14:53 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 17/39] thp, mm: handle tail pages in page_cache_get_speculative() Kirill A. Shutemov
2013-05-21 20:49 ` Dave Hansen
2013-06-27 12:40 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 18/39] thp, mm: add event counters for huge page alloc on write to a file Kirill A. Shutemov
2013-05-21 20:54 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 19/39] thp, mm: allocate huge pages in grab_cache_page_write_begin() Kirill A. Shutemov
2013-05-21 21:14 ` Dave Hansen
2013-05-30 13:20 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 20/39] thp, mm: naive support of thp in generic read/write routines Kirill A. Shutemov
2013-05-21 21:28 ` Dave Hansen
2013-06-07 15:17 ` Kirill A. Shutemov
2013-06-07 15:29 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 21/39] thp, libfs: initial support of thp in simple_read/write_begin/write_end Kirill A. Shutemov
2013-05-21 21:49 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 22/39] thp: handle file pages in split_huge_page() Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 23/39] thp: wait_split_huge_page(): serialize over i_mmap_mutex too Kirill A. Shutemov
2013-05-21 22:05 ` Dave Hansen
2013-06-03 15:02 ` Kirill A. Shutemov
2013-06-03 15:53 ` Dave Hansen
2013-06-03 16:09 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 24/39] thp, mm: truncate support for transparent huge page cache Kirill A. Shutemov
2013-05-21 22:39 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 25/39] thp, mm: split huge page on mmap file page Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 26/39] ramfs: enable transparent huge page cache Kirill A. Shutemov
2013-05-21 22:43 ` Dave Hansen
2013-05-22 14:22 ` Kirill A. Shutemov
2013-05-22 14:55 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 27/39] x86-64, mm: proper alignment mappings with hugepages Kirill A. Shutemov
2013-05-21 22:56 ` Dave Hansen
2013-06-25 14:56 ` Kirill A. Shutemov
2013-06-25 16:46 ` Dave Hansen
2013-05-21 23:20 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 28/39] thp: prepare zap_huge_pmd() to uncharge file pages Kirill A. Shutemov
2013-05-22 7:26 ` Hillf Danton
2013-05-12 1:23 ` [PATCHv4 29/39] thp: move maybe_pmd_mkwrite() out of mk_huge_pmd() Kirill A. Shutemov
2013-05-21 23:23 ` Dave Hansen
2013-05-22 14:37 ` Kirill A. Shutemov
2013-05-22 14:56 ` Dave Hansen
2013-05-21 23:23 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 30/39] thp: do_huge_pmd_anonymous_page() cleanup Kirill A. Shutemov
2013-05-22 11:45 ` Hillf Danton
2013-05-12 1:23 ` [PATCHv4 31/39] thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() Kirill A. Shutemov
2013-05-21 23:38 ` Dave Hansen
2013-05-22 6:51 ` Hillf Danton
2013-05-12 1:23 ` [PATCHv4 32/39] mm: cleanup __do_fault() implementation Kirill A. Shutemov
2013-05-21 23:57 ` Dave Hansen
2013-05-12 1:23 ` [PATCHv4 33/39] thp, mm: implement do_huge_linear_fault() Kirill A. Shutemov
2013-05-22 12:47 ` Hillf Danton
2013-05-22 15:13 ` Kirill A. Shutemov
2013-05-22 12:56 ` Hillf Danton
2013-05-22 15:14 ` Kirill A. Shutemov
2013-05-22 13:24 ` Hillf Danton
2013-05-22 15:26 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 34/39] thp, mm: handle huge pages in filemap_fault() Kirill A. Shutemov
2013-05-22 11:37 ` Hillf Danton
2013-05-22 15:34 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 35/39] mm: decomposite do_wp_page() and get rid of some 'goto' logic Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 36/39] mm: do_wp_page(): extract VM_WRITE|VM_SHARED case to separate function Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 37/39] thp: handle write-protect exception to file-backed huge pages Kirill A. Shutemov
2013-05-23 11:57 ` Hillf Danton
2013-05-23 12:08 ` Kirill A. Shutemov
2013-05-23 12:12 ` Hillf Danton
2013-05-23 12:33 ` Kirill A. Shutemov
2013-05-12 1:23 ` [PATCHv4 38/39] thp: vma_adjust_trans_huge(): adjust file-backed VMA too Kirill A. Shutemov
2013-05-23 11:01 ` Hillf Danton
2013-05-12 1:23 ` [PATCHv4 39/39] thp: map file-backed huge pages on fault Kirill A. Shutemov
2013-05-23 11:36 ` Hillf Danton
2013-05-23 11:48 ` Kirill A. Shutemov
2013-05-21 18:37 ` [PATCHv4 00/39] Transparent huge page cache Dave Hansen
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