From: Andrew Morton <akpm@linux-foundation.org>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>,
Paul Menage <menage@google.com>,
kamezawa.hiroyu@jp.fujitsu.com,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Jens Axboe <jens.axboe@oracle.com>,
"David S. Miller" <davem@davemloft.net>, Jan Kara <jack@suse.cz>,
Jes Sorensen <jes@sgi.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/7] mm: introduce simple_malloc()/simple_free()
Date: Sat, 15 Nov 2008 21:03:34 -0800 [thread overview]
Message-ID: <20081115210334.3870cdf6.akpm@linux-foundation.org> (raw)
In-Reply-To: <20081115205229.765f7ee3@infradead.org>
On Sat, 15 Nov 2008 20:52:29 -0800 Arjan van de Ven <arjan@infradead.org> wrote:
> On Sun, 16 Nov 2008 12:33:15 +0800
> Lai Jiangshan <laijs@cn.fujitsu.com> wrote:
>
> >
> > some subsystem needs vmalloc() when required memory is large.
> > but current kernel has not APIs for this requirement.
> > this patch introduces simple_malloc() and simple_free().
>
> Hi
>
> I kinda really don't like this approach. vmalloc() (and especially,
> vfree()) is a really expensive operation, and vmalloc()'d memory is
> also slower (due to tlb pressure).
And it can fragment, which effectively means a dead box.
> Realistically, people should try hard
> to use small datastructure instead....
Yup, it makes it easier for people to do something which we strongly
discourage. The risk got worse with all these 64-bit machines with
vast amounts of virtual address space. It makes it easier for people
to develop and "test" code which isn't reliable on smaller machines.
next prev parent reply other threads:[~2008-11-16 5:04 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-16 4:33 [PATCH 1/7] mm: introduce simple_malloc()/simple_free() Lai Jiangshan
2008-11-16 4:49 ` Alexey Dobriyan
2008-11-16 8:14 ` David Miller
2008-11-16 18:42 ` KOSAKI Motohiro
2008-11-16 4:52 ` Arjan van de Ven
2008-11-16 5:03 ` Andrew Morton [this message]
2008-11-16 5:35 ` Lai Jiangshan
2008-11-16 5:47 ` Andrew Morton
2008-11-16 5:53 ` Arjan van de Ven
2008-11-16 6:08 ` Eric Dumazet
2008-11-16 8:23 ` David Miller
2008-11-16 8:21 ` David Miller
2008-11-16 8:19 ` David Miller
2008-11-16 18:57 ` Arjan van de Ven
2008-11-16 21:39 ` Dave Airlie
2008-11-16 21:51 ` Arjan van de Ven
2008-11-16 22:42 ` Dave Airlie
2008-11-17 2:08 ` Lai Jiangshan
2008-11-17 4:53 ` Balbir Singh
2008-11-17 5:25 ` KAMEZAWA Hiroyuki
2008-11-17 6:43 ` KOSAKI Motohiro
2008-11-17 7:13 ` Andrew Morton
2008-11-17 7:15 ` David Miller
2008-11-17 8:10 ` KOSAKI Motohiro
2008-11-17 8:24 ` Balbir Singh
2008-11-18 4:39 ` Nick Piggin
2008-11-18 5:16 ` Lai Jiangshan
2008-11-17 4:46 ` Balbir Singh
2008-11-17 4:43 ` Balbir Singh
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