From: Goswin von Brederlow <brederlo@informatik.uni-tuebingen.de>
To: Andrea Arcangeli <andrea@suse.de>
Cc: Mel Gorman <mel@skynet.ie>,
Goswin von Brederlow <brederlo@informatik.uni-tuebingen.de>,
Andrew Morton <akpm@linux-foundation.org>,
Joern Engel <joern@logfs.org>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Christoph Lameter <clameter@sgi.com>,
torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
William Lee Irwin III <wli@holomorphy.com>,
David Chinner <dgc@sgi.com>, Jens Axboe <jens.axboe@oracle.com>,
Badari Pulavarty <pbadari@gmail.com>,
Maxim Levitsky <maximlevitsky@gmail.com>,
Fengguang Wu <fengguang.wu@gmail.com>,
swin wang <wangswin@gmail.com>,
totty.lu@gmail.com, hugh@veritas.com
Subject: Re: [00/41] Large Blocksize Support V7 (adds memmap support)
Date: Mon, 17 Sep 2007 00:56:07 +0200 [thread overview]
Message-ID: <87lkb643ug.fsf@informatik.uni-tuebingen.de> (raw)
In-Reply-To: <20070916185052.GG6708@v2.random> (Andrea Arcangeli's message of "Sun, 16 Sep 2007 20:50:52 +0200")
Andrea Arcangeli <andrea@suse.de> writes:
> You ignore one other bit, when "/usr/bin/free" says 1G is free, with
> config-page-shift it's free no matter what, same goes for not mlocked
> cache. With variable order page cache, /usr/bin/free becomes mostly a
> lie as long as there's no 4k fallback (like fsblock).
% free
total used free shared buffers cached
Mem: 1398784 1372956 25828 0 225224 321504
-/+ buffers/cache: 826228 572556
Swap: 1048568 20 1048548
When has free ever given any usefull "free" number? I can perfectly
fine allocate another gigabyte of memory despide free saing 25MB. But
that is because I know that the buffer/cached are not locked in.
On the other hand 1GB can instantly vanish when I start a xen domain
and anything relying on the free value would loose.
The only sensible thing for an application concerned with swapping is
to whatch the swapping and then reduce itself. Not the amount
free. Although I wish there were some kernel interface to get a
preasure value of how valuable free pages would be right now. I would
like that for fuse so a userspace filesystem can do caching without
cripling the kernel.
MfG
Goswin
next prev parent reply other threads:[~2007-09-16 22:56 UTC|newest]
Thread overview: 187+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-11 6:03 [00/41] Large Blocksize Support V7 (adds memmap support) Christoph Lameter
2007-09-10 18:52 ` Nick Piggin
2007-09-11 12:05 ` Andrea Arcangeli
2007-09-11 20:03 ` Christoph Lameter
2007-09-11 12:12 ` Jörn Engel
2007-09-10 21:13 ` Nick Piggin
2007-09-11 16:02 ` Goswin von Brederlow
2007-09-11 20:07 ` Christoph Lameter
2007-09-11 20:29 ` Jörn Engel
2007-09-11 20:41 ` Christoph Lameter
2007-09-11 23:26 ` Andrea Arcangeli
2007-09-12 0:04 ` Christoph Lameter
2007-09-12 8:20 ` Andrea Arcangeli
2007-09-15 8:44 ` Andrew Morton
2007-09-15 12:14 ` Goswin von Brederlow
2007-09-15 15:51 ` Andrea Arcangeli
2007-09-15 20:14 ` Goswin von Brederlow
2007-09-15 22:30 ` Andrea Arcangeli
2007-09-16 13:54 ` Goswin von Brederlow
2007-09-16 15:08 ` Andrea Arcangeli
2007-09-16 21:08 ` Mel Gorman
2007-09-16 22:48 ` Goswin von Brederlow
2007-09-17 9:30 ` Mel Gorman
2007-09-16 17:46 ` Jörn Engel
2007-09-16 18:15 ` Linus Torvalds
2007-09-16 18:21 ` Jörn Engel
2007-09-16 18:44 ` Linus Torvalds
2007-09-16 22:51 ` Goswin von Brederlow
2007-09-23 17:44 ` Jörn Engel
2007-09-16 22:06 ` Goswin von Brederlow
2007-09-16 22:40 ` Jörn Engel
2007-09-16 18:15 ` Mel Gorman
2007-09-16 18:50 ` Andrea Arcangeli
2007-09-16 20:54 ` Mel Gorman
2007-09-16 21:31 ` Andrea Arcangeli
2007-09-17 10:13 ` Mel Gorman
2007-09-23 5:50 ` Goswin von Brederlow
2007-09-16 22:56 ` Goswin von Brederlow [this message]
2007-09-18 19:31 ` Andrea Arcangeli
2007-09-23 6:56 ` Goswin von Brederlow
2007-09-24 15:39 ` Andrea Arcangeli
2007-09-16 18:13 ` Mel Gorman
2007-09-16 9:03 ` Nick Piggin
2007-09-17 22:00 ` Christoph Lameter
2007-09-18 0:11 ` Nick Piggin
2007-09-18 20:36 ` Christoph Lameter
2007-09-18 10:00 ` Mel Gorman
2007-09-18 10:49 ` Jörn Engel
2007-09-18 12:31 ` David Chinner
2007-09-16 21:58 ` Goswin von Brederlow
2007-09-17 10:03 ` Mel Gorman
2007-09-23 6:22 ` Goswin von Brederlow
2007-09-24 12:32 ` Kyle Moffett
2007-09-16 17:53 ` Jörn Engel
2007-09-16 21:31 ` Mel Gorman
2007-09-17 22:03 ` Christoph Lameter
2007-09-11 15:36 ` Mel Gorman
2007-09-11 1:44 ` Nick Piggin
2007-09-11 20:11 ` Christoph Lameter
2007-09-11 4:53 ` Nick Piggin
2007-09-11 20:42 ` Christoph Lameter
2007-09-11 5:30 ` Nick Piggin
2007-09-11 21:41 ` Christoph Lameter
2007-09-11 6:06 ` Nick Piggin
2007-09-11 21:52 ` Christoph Lameter
2007-09-11 18:07 ` Nick Piggin
2007-09-12 23:06 ` Christoph Lameter
2007-09-13 20:51 ` Nick Piggin
2007-09-14 17:52 ` Christoph Lameter
2007-09-16 8:22 ` Nick Piggin
2007-09-17 22:05 ` Christoph Lameter
2007-09-18 0:10 ` Nick Piggin
2007-09-18 20:42 ` Christoph Lameter
2007-09-17 11:10 ` Bernd Schmidt
2007-09-17 22:10 ` Christoph Lameter
2007-09-14 16:10 ` Goswin von Brederlow
2007-09-14 17:42 ` Mel Gorman
2007-09-15 0:31 ` Goswin von Brederlow
2007-09-16 21:16 ` Mel Gorman
2007-09-16 22:38 ` Goswin von Brederlow
2007-09-17 8:57 ` Mel Gorman
2007-09-23 6:49 ` Goswin von Brederlow
2007-09-11 20:53 ` Mel Gorman
2007-09-11 6:00 ` Nick Piggin
2007-09-11 21:48 ` Christoph Lameter
2007-09-11 6:17 ` Nick Piggin
2007-09-12 0:00 ` Christoph Lameter
2007-09-12 2:46 ` Nick Piggin
2007-09-12 23:17 ` Christoph Lameter
2007-09-13 9:40 ` Mel Gorman
2007-09-14 2:38 ` Christoph Lameter
2007-09-13 21:20 ` Nick Piggin
2007-09-14 18:08 ` Christoph Lameter
2007-09-14 18:15 ` Christoph Lameter
2007-09-15 0:33 ` Goswin von Brederlow
2007-09-16 8:53 ` Nick Piggin
2007-09-17 22:21 ` Christoph Lameter
2007-09-18 1:16 ` Nick Piggin
2007-09-18 18:30 ` Linus Torvalds
2007-09-18 17:53 ` Nick Piggin
2007-09-18 19:18 ` Andrea Arcangeli
2007-09-18 19:44 ` Linus Torvalds
2007-09-19 0:58 ` Nathan Scott
2007-09-19 1:06 ` Linus Torvalds
2007-09-19 2:45 ` Nathan Scott
2007-09-19 5:09 ` David Chinner
2007-09-19 9:41 ` Alex Tomas
2007-09-19 14:04 ` Andrea Arcangeli
2007-09-20 1:38 ` David Chinner
2007-09-20 14:54 ` Andrea Arcangeli
2007-09-20 18:11 ` Christoph Lameter
2007-09-20 18:07 ` Christoph Lameter
2007-09-21 20:41 ` Hugh Dickins
2007-09-24 21:13 ` Christoph Lameter
2007-09-28 2:46 ` Nick Piggin
2007-09-19 3:41 ` Rene Herman
2007-09-19 3:50 ` Linus Torvalds
2007-09-19 4:26 ` Rene Herman
2007-09-19 4:33 ` Linus Torvalds
2007-09-19 4:56 ` Rene Herman
2007-09-11 21:54 ` Mel Gorman
2007-09-12 14:29 ` Martin J. Bligh
2007-09-12 1:49 ` David Chinner
2007-09-11 15:27 ` Nick Piggin
2007-09-13 1:49 ` David Chinner
2007-09-12 17:23 ` Nick Piggin
2007-09-13 13:03 ` David Chinner
2007-09-13 2:01 ` Nick Piggin
2007-09-13 20:48 ` Nick Piggin
2007-09-17 4:07 ` David Chinner
2007-09-16 21:13 ` Nick Piggin
2007-09-12 2:01 ` Nick Piggin
2007-09-11 21:35 ` Christoph Lameter
2007-09-11 16:47 ` Andrea Arcangeli
2007-09-11 18:31 ` Mel Gorman
2007-09-11 2:26 ` Nick Piggin
2007-09-11 18:25 ` Maxim Levitsky
2007-09-11 3:05 ` Nick Piggin
2007-09-11 21:03 ` Mel Gorman
2007-09-11 19:20 ` Andrea Arcangeli
2007-09-11 20:19 ` Jörn Engel
2007-09-11 20:13 ` Christoph Lameter
2007-09-11 20:01 ` Christoph Lameter
2007-09-11 4:43 ` Nick Piggin
2007-09-11 5:17 ` Nick Piggin
2007-09-11 21:27 ` Mel Gorman
2007-09-11 6:03 ` [01/41] Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user Christoph Lameter
2007-09-11 6:03 ` [02/41] Define functions for page cache handling Christoph Lameter
2007-09-11 6:03 ` [03/41] Use page_cache_xxx functions in mm/filemap.c Christoph Lameter
2007-09-11 6:03 ` [04/41] Use page_cache_xxx in mm/page-writeback.c Christoph Lameter
2007-09-11 6:03 ` [05/41] Use page_cache_xxx in mm/truncate.c Christoph Lameter
2007-09-11 6:03 ` [06/41] Use page_cache_xxx in mm/rmap.c Christoph Lameter
2007-09-11 6:03 ` [07/41] Use page_cache_xxx in mm/filemap_xip.c Christoph Lameter
2007-09-11 6:03 ` [08/41] Use page_cache_xxx in mm/migrate.c Christoph Lameter
2007-09-11 6:03 ` [09/41] Use page_cache_xxx in fs/libfs.c Christoph Lameter
2007-09-11 6:04 ` [10/41] Use page_cache_xxx in fs/sync Christoph Lameter
2007-09-11 6:04 ` [11/41] Use page_cache_xxx in fs/buffer.c Christoph Lameter
2007-09-11 6:04 ` [12/41] Use page_cache_xxx in mm/mpage.c Christoph Lameter
2007-09-11 6:04 ` [13/41] Use page_cache_xxx in mm/fadvise.c Christoph Lameter
2007-09-11 6:04 ` [14/41] Use page_cache_xxx in fs/splice.c Christoph Lameter
2007-09-11 6:04 ` [15/41] Use page_cache_xxx in ext2 Christoph Lameter
2007-09-11 6:04 ` [16/41] Use page_cache_xxx in fs/ext3 Christoph Lameter
2007-09-11 6:04 ` [17/41] Use page_cache_xxx in fs/ext4 Christoph Lameter
2007-09-11 6:04 ` [18/41] Use page_cache_xxx in fs/reiserfs Christoph Lameter
2007-09-11 6:04 ` [19/41] Use page_cache_xxx for fs/xfs Christoph Lameter
2007-09-11 6:04 ` [20/41] Use page_cache_xxx in drivers/block/rd.c Christoph Lameter
2007-09-11 6:04 ` [21/41] compound pages: Better PageHead/PageTail handling Christoph Lameter
2007-09-11 6:04 ` [22/41] compound pages: Add new support functions Christoph Lameter
2007-09-11 6:04 ` [23/41] compound pages: vmstat support Christoph Lameter
2007-09-11 6:04 ` [24/41] compound pages: Use new compound vmstat functions in SLUB Christoph Lameter
2007-09-11 6:04 ` [25/41] compound pages: Allow use of get_page_unless_zero with compound pages Christoph Lameter
2007-09-11 6:04 ` [26/41] compound pages: Allow freeing of compound pages via pagevec Christoph Lameter
2007-09-11 6:04 ` [27/41] Large page order operations, zeroing and flushing Christoph Lameter
2007-09-11 6:04 ` [28/41] Futex: Fix PAGE SIZE assumption Christoph Lameter
2007-09-11 6:04 ` [29/41] Fix up reclaim counters Christoph Lameter
2007-09-11 6:04 ` [30/41] Add VM_BUG_ONs to check for correct page order Christoph Lameter
2007-09-11 6:04 ` [31/41] Large Blocksize: Core piece Christoph Lameter
2007-09-11 6:04 ` [32/41] Readahead changes to support large blocksize Christoph Lameter
2007-09-11 6:04 ` [33/41] Large blocksize support in ramfs Christoph Lameter
2007-09-11 6:04 ` [34/41] Large blocksize support for XFS Christoph Lameter
2007-09-11 6:04 ` [35/41] Reiserfs: Fix up mapping_set_gfp_mask() Christoph Lameter
2007-09-11 6:04 ` [36/41] 64k block size support for Ext2/3/4 Christoph Lameter
2007-09-11 6:04 ` [37/41] ext2: fix rec_len overflow for 64KB block size Christoph Lameter
2007-09-11 6:04 ` [38/41] ext3: fix rec_len overflow with " Christoph Lameter
2007-09-11 6:04 ` [39/41] ext4: fix rec_len overflow for " Christoph Lameter
2007-09-11 6:04 ` [40/41] Do not use f_mapping in simple_prepare_write() Christoph Lameter
2007-09-11 6:04 ` [41/41] Mmap support using pte PAGE_SIZE mappings Christoph Lameter
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