From: Nick Piggin <npiggin@suse.de>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, John Stultz <johnstul@us.ibm.com>,
Frank Mayhar <fmayhar@google.com>
Subject: Re: [patch 50/52] mm: implement per-zone shrinker
Date: Fri, 25 Jun 2010 02:00:52 +1000 [thread overview]
Message-ID: <20100624160052.GL10441@laptop> (raw)
In-Reply-To: <87aaqkagn9.fsf@basil.nowhere.org>
On Thu, Jun 24, 2010 at 12:06:50PM +0200, Andi Kleen wrote:
> npiggin@suse.de writes:
>
> > Allow the shrinker to do per-zone shrinking. This means it is called for
> > each zone scanned. The shrinker is now completely responsible for calculating
> > and batching (given helpers), which provides better flexibility.
>
> Beyond the scope of this patch, but at some point this probably needs
> to be even more fine grained. With large number of cores/threads in
> each socket a "zone" is actually shared by quite a large number
> of CPUs now and this can cause problems.
Yes, possibly. At least it is a much better step than the big dumb
global list.
> > +void shrinker_add_scan(unsigned long *dst,
> > + unsigned long scanned, unsigned long total,
> > + unsigned long objects, unsigned int ratio)
> > +{
> > + unsigned long long delta;
> > +
> > + delta = (unsigned long long)scanned * objects * ratio;
> > + do_div(delta, total + 1);
> > + delta /= (128ULL / 4ULL);
>
> Again I object to the magic numbers ...
>
> > + nr += shrink_slab(zone, 1, 1, 1, GFP_KERNEL);
> > + if (nr >= 10)
> > + goto again;
>
> And here.
I don't like them either -- problem is they were inherited from the
old code (actually 128 is the fixed point scale, I do have a define
for it just forgot to use it).
I don't know where 4 came from. And 10 is just a random number someone
picked out of a hat :P
> Overall it seems good, but I have not read all the shrinker callback
> changes in all subsystems.
Thanks for looking over it Andi.
next prev parent reply other threads:[~2010-06-24 16:00 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-24 3:02 [patch 00/52] vfs scalability patches updated npiggin
2010-06-24 3:02 ` [patch 01/52] kernel: add bl_list npiggin
2010-06-24 6:04 ` Eric Dumazet
2010-06-24 14:42 ` Nick Piggin
2010-06-24 16:01 ` Eric Dumazet
2010-06-28 21:37 ` Paul E. McKenney
2010-06-29 6:30 ` Nick Piggin
2010-06-24 3:02 ` [patch 02/52] fs: fix superblock iteration race npiggin
2010-06-29 13:02 ` Christoph Hellwig
2010-06-29 14:56 ` Nick Piggin
2010-06-29 17:35 ` Linus Torvalds
2010-06-29 17:41 ` Nick Piggin
2010-06-29 17:52 ` Linus Torvalds
2010-06-29 17:58 ` Linus Torvalds
2010-06-29 20:04 ` Chris Clayton
2010-06-29 20:14 ` Nick Piggin
2010-06-29 20:38 ` Chris Clayton
2010-06-30 7:13 ` Chris Clayton
2010-06-30 12:51 ` Al Viro
2010-06-24 3:02 ` [patch 03/52] fs: fs_struct rwlock to spinlock npiggin
2010-06-24 3:02 ` [patch 04/52] fs: cleanup files_lock npiggin
2010-06-24 3:02 ` [patch 05/52] lglock: introduce special lglock and brlock spin locks npiggin
2010-06-24 18:15 ` Thomas Gleixner
2010-06-25 6:22 ` Nick Piggin
2010-06-25 9:50 ` Thomas Gleixner
2010-06-25 10:11 ` Nick Piggin
2010-06-24 3:02 ` [patch 06/52] fs: scale files_lock npiggin
2010-06-24 7:52 ` Peter Zijlstra
2010-06-24 15:00 ` Nick Piggin
2010-06-24 3:02 ` [patch 07/52] fs: brlock vfsmount_lock npiggin
2010-06-24 3:02 ` [patch 08/52] fs: scale mntget/mntput npiggin
2010-06-24 3:02 ` [patch 09/52] fs: dcache scale hash npiggin
2010-06-24 3:02 ` [patch 10/52] fs: dcache scale lru npiggin
2010-06-24 3:02 ` [patch 11/52] fs: dcache scale nr_dentry npiggin
2010-06-24 3:02 ` [patch 12/52] fs: dcache scale dentry refcount npiggin
2010-06-24 3:02 ` [patch 13/52] fs: dcache scale d_unhashed npiggin
2010-06-24 3:02 ` [patch 14/52] fs: dcache scale subdirs npiggin
2010-06-24 7:56 ` Peter Zijlstra
2010-06-24 9:50 ` Andi Kleen
2010-06-24 15:53 ` Nick Piggin
2010-06-24 3:02 ` [patch 15/52] fs: dcache scale inode alias list npiggin
2010-06-24 3:02 ` [patch 16/52] fs: dcache RCU for multi-step operaitons npiggin
2010-06-24 7:58 ` Peter Zijlstra
2010-06-24 15:03 ` Nick Piggin
2010-06-24 17:22 ` john stultz
2010-06-24 17:26 ` john stultz
2010-06-25 6:45 ` Nick Piggin
2010-06-24 3:02 ` [patch 17/52] fs: dcache remove dcache_lock npiggin
2010-06-24 3:02 ` [patch 18/52] fs: dcache reduce dput locking npiggin
2010-06-24 3:02 ` [patch 19/52] fs: dcache per-bucket dcache hash locking npiggin
2010-06-24 3:02 ` [patch 20/52] fs: dcache reduce dcache_inode_lock npiggin
2010-06-24 3:02 ` [patch 21/52] fs: dcache per-inode inode alias locking npiggin
2010-06-24 3:02 ` [patch 22/52] fs: dcache rationalise dget variants npiggin
2010-06-24 3:02 ` [patch 23/52] fs: dcache percpu nr_dentry npiggin
2010-06-24 3:02 ` [patch 24/52] fs: dcache reduce d_parent locking npiggin
2010-06-24 8:44 ` Peter Zijlstra
2010-06-24 15:07 ` Nick Piggin
2010-06-24 15:32 ` Paul E. McKenney
2010-06-24 16:05 ` Nick Piggin
2010-06-24 16:41 ` Paul E. McKenney
2010-06-28 21:50 ` Paul E. McKenney
2010-07-07 14:35 ` Nick Piggin
2010-06-24 3:02 ` [patch 25/52] fs: dcache DCACHE_REFERENCED improve npiggin
2010-06-24 3:02 ` [patch 26/52] fs: icache lock s_inodes list npiggin
2010-06-24 3:02 ` [patch 27/52] fs: icache lock inode hash npiggin
2010-06-24 3:02 ` [patch 28/52] fs: icache lock i_state npiggin
2010-06-24 3:02 ` [patch 29/52] fs: icache lock i_count npiggin
2010-06-30 7:27 ` Dave Chinner
2010-06-30 12:05 ` Nick Piggin
2010-07-01 2:36 ` Dave Chinner
2010-07-01 7:54 ` Nick Piggin
2010-07-01 9:36 ` Nick Piggin
2010-07-01 16:21 ` Frank Mayhar
2010-07-03 2:03 ` Andrew Morton
2010-07-03 3:41 ` Nick Piggin
2010-07-03 4:31 ` Andrew Morton
2010-07-03 5:06 ` Nick Piggin
2010-07-03 5:18 ` Nick Piggin
2010-07-05 22:41 ` Dave Chinner
2010-07-06 4:34 ` Nick Piggin
2010-07-06 10:38 ` Theodore Tso
2010-07-06 13:04 ` Nick Piggin
2010-07-07 17:00 ` Frank Mayhar
2010-06-24 3:02 ` [patch 30/52] fs: icache lock lru/writeback lists npiggin
2010-06-24 8:58 ` Peter Zijlstra
2010-06-24 15:09 ` Nick Piggin
2010-06-24 15:13 ` Peter Zijlstra
2010-06-24 3:02 ` [patch 31/52] fs: icache atomic inodes_stat npiggin
2010-06-24 3:02 ` [patch 32/52] fs: icache protect inode state npiggin
2010-06-24 3:02 ` [patch 33/52] fs: icache atomic last_ino, iunique lock npiggin
2010-06-24 3:02 ` [patch 34/52] fs: icache remove inode_lock npiggin
2010-06-24 3:02 ` [patch 35/52] fs: icache factor hash lock into functions npiggin
2010-06-24 3:02 ` [patch 36/52] fs: icache per-bucket inode hash locks npiggin
2010-06-24 3:02 ` [patch 37/52] fs: icache lazy lru npiggin
2010-06-24 9:52 ` Andi Kleen
2010-06-24 15:59 ` Nick Piggin
2010-06-30 8:38 ` Dave Chinner
2010-06-30 12:06 ` Nick Piggin
2010-07-01 2:46 ` Dave Chinner
2010-07-01 7:57 ` Nick Piggin
2010-06-24 3:02 ` [patch 38/52] fs: icache RCU free inodes npiggin
2010-06-30 8:57 ` Dave Chinner
2010-06-30 12:07 ` Nick Piggin
2010-06-24 3:02 ` [patch 39/52] fs: icache rcu walk for i_sb_list npiggin
2010-06-24 3:02 ` [patch 40/52] fs: dcache improve scalability of pseudo filesystems npiggin
2010-06-24 3:02 ` [patch 41/52] fs: icache reduce atomics npiggin
2010-06-24 3:02 ` [patch 42/52] fs: icache per-cpu last_ino allocator npiggin
2010-06-24 9:48 ` Andi Kleen
2010-06-24 15:52 ` Nick Piggin
2010-06-24 16:19 ` Andi Kleen
2010-06-24 16:38 ` Nick Piggin
2010-06-24 3:02 ` [patch 43/52] fs: icache per-cpu nr_inodes counter npiggin
2010-06-24 3:02 ` [patch 44/52] fs: icache per-CPU sb inode lists and locks npiggin
2010-06-30 9:26 ` Dave Chinner
2010-06-30 12:08 ` Nick Piggin
2010-07-01 3:12 ` Dave Chinner
2010-07-01 8:00 ` Nick Piggin
2010-06-24 3:02 ` [patch 45/52] fs: icache RCU hash lookups npiggin
2010-06-24 3:02 ` [patch 46/52] fs: icache reduce locking npiggin
2010-06-24 3:02 ` [patch 47/52] fs: keep inode with backing-dev npiggin
2010-06-24 3:03 ` [patch 48/52] fs: icache split IO and LRU lists npiggin
2010-06-24 3:03 ` [patch 49/52] fs: icache scale writeback list locking npiggin
2010-06-24 3:03 ` [patch 50/52] mm: implement per-zone shrinker npiggin
2010-06-24 10:06 ` Andi Kleen
2010-06-24 16:00 ` Nick Piggin [this message]
2010-06-24 16:27 ` Andi Kleen
2010-06-24 16:32 ` Andi Kleen
2010-06-24 16:37 ` Andi Kleen
2010-06-30 6:28 ` Dave Chinner
2010-06-30 12:03 ` Nick Piggin
2010-06-24 3:03 ` [patch 51/52] fs: per-zone dentry and inode LRU npiggin
2010-06-30 10:09 ` Dave Chinner
2010-06-30 12:13 ` Nick Piggin
2010-06-24 3:03 ` [patch 52/52] fs: icache less I_FREEING time npiggin
2010-06-30 10:13 ` Dave Chinner
2010-06-30 12:14 ` Nick Piggin
2010-07-01 3:33 ` Dave Chinner
2010-07-01 8:06 ` Nick Piggin
2010-06-25 7:12 ` [patch 00/52] vfs scalability patches updated Christoph Hellwig
2010-06-25 8:05 ` Nick Piggin
2010-06-30 11:30 ` Dave Chinner
2010-06-30 12:40 ` Nick Piggin
2010-07-01 3:56 ` Dave Chinner
2010-07-01 8:20 ` Nick Piggin
2010-07-01 17:36 ` Andi Kleen
2010-07-01 17:23 ` Nick Piggin
2010-07-01 17:28 ` Andi Kleen
2010-07-06 17:49 ` Nick Piggin
2010-07-01 17:35 ` Linus Torvalds
2010-07-01 17:52 ` Nick Piggin
2010-07-02 4:01 ` Paul E. McKenney
2010-06-30 17:08 ` Frank Mayhar
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