From: Pekka Enberg <penberg@cs.helsinki.fi>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@sgi.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
netdev@vger.kernel.org,
Trond Myklebust <trond.myklebust@fys.uio.no>,
Thomas Graf <tgraf@suug.ch>, David Miller <davem@davemloft.net>,
James Bottomley <James.Bottomley@SteelEye.com>,
Mike Christie <michaelc@cs.wisc.edu>,
Andrew Morton <akpm@linux-foundation.org>,
Daniel Phillips <phillips@google.com>
Subject: Re: [PATCH 08/40] mm: kmem_cache_objsize
Date: Fri, 04 May 2007 21:45:55 +0300 [thread overview]
Message-ID: <463B7F63.8070508@cs.helsinki.fi> (raw)
In-Reply-To: <1178303538.2767.9.camel@lappy>
On Fri, 2007-05-04 at 11:30 -0700, Christoph Lameter wrote:
> > Hmmm... Maybe lets have
> >
> > unsigned kmem_estimate_pages(struct kmem_cache *slab_cache, int objects)
> >
> > which would calculate the worst case memory scenario for allocation the
> > number of indicated objects?
On Fri, 4 May 2007, Peter Zijlstra wrote:
> Perfectly fine with me, Pekka, any objections?
Again, slab has no way of actually estimating how many pages you need
for a given number of objects. So we end up calculating some upper bound
which doesn't belong in mm/slab.c. I am perfectly okay with:
(1) kmem_nr_bytes_per_object which is what Peter has now
or alternatively,
(2) kmem_nr_objects_per_page which I think Christoph suggested
Both of them, the slab knows the answer, and doesn't need to guess. It's
up to the caller to figure out what the acceptable upper bound is.
Pekka
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next prev parent reply other threads:[~2007-05-04 18:45 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-04 10:26 [PATCH 00/40] Swap over Networked storage -v12 Peter Zijlstra
2007-05-04 10:26 ` [PATCH 01/40] mm: page allocation rank Peter Zijlstra
2007-05-04 10:26 ` [PATCH 02/40] mm: slab allocation fairness Peter Zijlstra
2007-05-16 20:41 ` Christoph Lameter
2007-05-04 10:26 ` [PATCH 03/40] mm: allow PF_MEMALLOC from softirq context Peter Zijlstra
2007-05-04 10:26 ` [PATCH 04/40] mm: serialize access to min_free_kbytes Peter Zijlstra
2007-05-04 10:26 ` [PATCH 05/40] mm: emergency pool Peter Zijlstra
2007-05-04 10:26 ` [PATCH 06/40] mm: __GFP_EMERGENCY Peter Zijlstra
2007-05-04 10:26 ` [PATCH 07/40] mm: allow mempool to fall back to memalloc reserves Peter Zijlstra
2007-05-04 10:26 ` [PATCH 08/40] mm: kmem_cache_objsize Peter Zijlstra
2007-05-04 10:54 ` Pekka Enberg
2007-05-04 16:09 ` Christoph Lameter
2007-05-04 16:15 ` Peter Zijlstra
2007-05-04 16:23 ` Christoph Lameter
2007-05-04 16:30 ` Peter Zijlstra
2007-05-04 16:36 ` Christoph Lameter
2007-05-04 17:59 ` Peter Zijlstra
2007-05-04 18:04 ` Christoph Lameter
2007-05-04 18:21 ` Peter Zijlstra
2007-05-04 18:30 ` Christoph Lameter
2007-05-04 18:32 ` Peter Zijlstra
2007-05-04 18:45 ` Pekka Enberg [this message]
2007-05-04 18:47 ` Christoph Lameter
2007-05-04 18:54 ` Pekka Enberg
2007-05-04 19:59 ` Christoph Lameter
2007-05-05 9:00 ` Pekka J Enberg
2007-05-04 18:41 ` Pekka Enberg
2007-05-04 18:46 ` Christoph Lameter
2007-05-04 18:53 ` Pekka Enberg
2007-05-04 19:58 ` Christoph Lameter
2007-05-04 10:27 ` [PATCH 09/40] mm: optimize gfp_to_rank() Peter Zijlstra
2007-05-04 10:27 ` [PATCH 10/40] selinux: tag avc cache alloc as non-critical Peter Zijlstra
2007-05-04 10:27 ` [PATCH 11/40] net: wrap sk->sk_backlog_rcv() Peter Zijlstra
2007-05-04 10:27 ` [PATCH 12/40] net: packet split receive api Peter Zijlstra
2007-05-04 10:27 ` [PATCH 13/40] net: sk_allocation() - concentrate socket related allocations Peter Zijlstra
2007-05-04 10:27 ` [PATCH 14/40] netvm: link network to vm layer Peter Zijlstra
2007-05-04 10:27 ` [PATCH 15/40] netvm: INET reserves Peter Zijlstra
2007-05-04 10:27 ` [PATCH 16/40] netvm: hook skb allocation to reserves Peter Zijlstra
2007-05-04 14:07 ` Arnaldo Carvalho de Melo
2007-05-04 10:27 ` [PATCH 17/40] netvm: filter emergency skbs Peter Zijlstra
2007-05-04 10:27 ` [PATCH 18/40] netvm: prevent a TCP specific deadlock Peter Zijlstra
2007-05-04 10:27 ` [PATCH 19/40] netfilter: notify about NF_QUEUE vs emergency skbs Peter Zijlstra
2007-05-04 10:27 ` [PATCH 20/40] netvm: skb processing Peter Zijlstra
2007-05-04 10:27 ` [PATCH 21/40] uml: rename arch/um remove_mapping() Peter Zijlstra
2007-05-04 10:27 ` [PATCH 22/40] mm: prepare swap entry methods for use in page methods Peter Zijlstra
2007-05-04 10:27 ` [PATCH 23/40] mm: add support for non block device backed swap files Peter Zijlstra
2007-05-04 10:27 ` [PATCH 24/40] mm: methods for teaching filesystems about PG_swapcache pages Peter Zijlstra
2007-05-04 10:27 ` [PATCH 25/40] nfs: remove mempools Peter Zijlstra
2007-05-04 10:27 ` [PATCH 26/40] nfs: teach the NFS client how to treat PG_swapcache pages Peter Zijlstra
2007-05-04 10:27 ` [PATCH 27/40] nfs: disable data cache revalidation for swapfiles Peter Zijlstra
2007-05-04 10:27 ` [PATCH 28/40] nfs: enable swap on NFS Peter Zijlstra
2007-05-04 10:27 ` [PATCH 29/40] nfs: fix various memory recursions possible with swap over NFS Peter Zijlstra
2007-05-04 10:27 ` [PATCH 30/40] nfs: fixup missing error code Peter Zijlstra
2007-05-04 13:10 ` Peter Staubach
2007-05-04 13:18 ` Peter Zijlstra
2007-05-04 10:27 ` [PATCH 31/40] mm: balance_dirty_pages() vs throttle_vm_writeout() deadlock Peter Zijlstra
2007-05-04 10:27 ` [PATCH 32/40] block: add a swapdev callback to the request_queue Peter Zijlstra
2007-05-04 10:27 ` [PATCH 33/40] uml: enable scsi and add iscsi config Peter Zijlstra
2007-05-04 10:27 ` [PATCH 34/40] sock: safely expose kernel sockets to userspace Peter Zijlstra
2007-05-04 10:27 ` [PATCH 35/40] From: Mike Christie <mchristi@redhat.com> Peter Zijlstra
2007-05-04 10:27 ` [PATCH 36/40] iscsi: fixup of the ep_connect patch Peter Zijlstra
2007-05-04 10:27 ` [PATCH 37/40] iscsi: ensure the iscsi kernel fd is not usable in userspace Peter Zijlstra
2007-05-04 10:27 ` [PATCH 38/40] netlink: add SOCK_VMIO support to AF_NETLINK Peter Zijlstra
2007-05-04 10:27 ` [PATCH 39/40] mm: a process flags to avoid blocking allocations Peter Zijlstra
2007-05-04 10:27 ` [PATCH 40/40] iscsi: support for swapping over iSCSI Peter Zijlstra
2007-05-04 15:22 ` [PATCH 00/40] Swap over Networked storage -v12 Daniel Walker
2007-05-04 15:38 ` Peter Zijlstra
2007-05-04 15:59 ` Daniel Walker
2007-05-04 18:09 ` Mike Snitzer
2007-05-04 19:31 ` Daniel Walker
2007-05-04 19:54 ` David Miller, Mike Snitzer
2007-05-04 21:36 ` Arnaldo Carvalho de Melo
2007-05-04 19:27 ` David Miller, Peter Zijlstra
2007-05-04 19:41 ` Peter Zijlstra
2007-05-04 20:02 ` David Miller, Peter Zijlstra
2007-05-04 20:29 ` Jeff Garzik
2007-05-05 9:43 ` Christoph Hellwig
2007-05-05 9:55 ` William Lee Irwin III
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