From: will.huckk@gmail.com (Will Huck)
To: linux-arm-kernel@lists.infradead.org
Subject: Should a swapped out page be deleted from swap cache?
Date: Wed, 20 Feb 2013 08:43:30 +0800 [thread overview]
Message-ID: <51241C32.3050500@gmail.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1302191056390.2248@eggly.anvils>
On 02/20/2013 03:06 AM, Hugh Dickins wrote:
> On Tue, 19 Feb 2013, Will Huck wrote:
>> Another question:
> I don't see the connection to deleting a swapped out page from swap cache.
>
>> Why kernel memory mapping use direct mapping instead of kmalloc/vmalloc which
>> will setup mapping on demand?
> I may misunderstand you, and "kernel memory mapping".
>
> kmalloc does not set up a mapping, it uses the direct mapping already set up.
>
> It would be circular if the basic page allocation primitives used kmalloc,
> since kmalloc relies on the basic page allocation primitives.
>
> vmalloc is less efficient than using the direct mapping (repeated setup
> and teardown, no use of hugepages), but necessary when you want a larger
Is there tlb flush in setup and teardown process? and they also expensive?
> virtual array than you're likely to find from the buddy allocator.
>
> Hugh
WARNING: multiple messages have this Message-ID (diff)
From: Will Huck <will.huckk@gmail.com>
To: Hugh Dickins <hughd@google.com>
Cc: Li Haifeng <omycle@gmail.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: Should a swapped out page be deleted from swap cache?
Date: Wed, 20 Feb 2013 08:43:30 +0800 [thread overview]
Message-ID: <51241C32.3050500@gmail.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1302191056390.2248@eggly.anvils>
On 02/20/2013 03:06 AM, Hugh Dickins wrote:
> On Tue, 19 Feb 2013, Will Huck wrote:
>> Another question:
> I don't see the connection to deleting a swapped out page from swap cache.
>
>> Why kernel memory mapping use direct mapping instead of kmalloc/vmalloc which
>> will setup mapping on demand?
> I may misunderstand you, and "kernel memory mapping".
>
> kmalloc does not set up a mapping, it uses the direct mapping already set up.
>
> It would be circular if the basic page allocation primitives used kmalloc,
> since kmalloc relies on the basic page allocation primitives.
>
> vmalloc is less efficient than using the direct mapping (repeated setup
> and teardown, no use of hugepages), but necessary when you want a larger
Is there tlb flush in setup and teardown process? and they also expensive?
> virtual array than you're likely to find from the buddy allocator.
>
> Hugh
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WARNING: multiple messages have this Message-ID (diff)
From: Will Huck <will.huckk@gmail.com>
To: Hugh Dickins <hughd@google.com>
Cc: Li Haifeng <omycle@gmail.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: Should a swapped out page be deleted from swap cache?
Date: Wed, 20 Feb 2013 08:43:30 +0800 [thread overview]
Message-ID: <51241C32.3050500@gmail.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1302191056390.2248@eggly.anvils>
On 02/20/2013 03:06 AM, Hugh Dickins wrote:
> On Tue, 19 Feb 2013, Will Huck wrote:
>> Another question:
> I don't see the connection to deleting a swapped out page from swap cache.
>
>> Why kernel memory mapping use direct mapping instead of kmalloc/vmalloc which
>> will setup mapping on demand?
> I may misunderstand you, and "kernel memory mapping".
>
> kmalloc does not set up a mapping, it uses the direct mapping already set up.
>
> It would be circular if the basic page allocation primitives used kmalloc,
> since kmalloc relies on the basic page allocation primitives.
>
> vmalloc is less efficient than using the direct mapping (repeated setup
> and teardown, no use of hugepages), but necessary when you want a larger
Is there tlb flush in setup and teardown process? and they also expensive?
> virtual array than you're likely to find from the buddy allocator.
>
> Hugh
next prev parent reply other threads:[~2013-02-20 0:43 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 10:48 Should a swapped out page be deleted from swap cache? Li Haifeng
2013-02-18 10:48 ` Li Haifeng
2013-02-18 10:48 ` Li Haifeng
2013-02-18 18:06 ` Hugh Dickins
2013-02-18 18:06 ` Hugh Dickins
2013-02-18 18:06 ` Hugh Dickins
2013-02-19 0:39 ` Will Huck
2013-02-19 0:39 ` Will Huck
2013-02-19 0:39 ` Will Huck
2013-02-19 19:06 ` Hugh Dickins
2013-02-19 19:06 ` Hugh Dickins
2013-02-19 19:06 ` Hugh Dickins
2013-02-20 0:43 ` Will Huck [this message]
2013-02-20 0:43 ` Will Huck
2013-02-20 0:43 ` Will Huck
2013-02-19 2:04 ` Li Haifeng
2013-02-19 2:04 ` Li Haifeng
2013-02-19 2:04 ` Li Haifeng
2013-02-19 2:38 ` Will Huck
2013-02-19 2:38 ` Will Huck
2013-02-19 2:38 ` Will Huck
2013-02-19 6:53 ` Li Haifeng
2013-02-19 6:53 ` Li Haifeng
2013-02-19 6:53 ` Li Haifeng
2013-02-19 9:38 ` Sha Zhengju
2013-02-19 9:38 ` Sha Zhengju
2013-02-19 9:38 ` Sha Zhengju
2013-02-19 18:49 ` Hugh Dickins
2013-02-19 18:49 ` Hugh Dickins
2013-02-19 18:49 ` Hugh Dickins
2013-02-19 8:32 ` Ric Mason
2013-02-19 8:32 ` Ric Mason
2013-02-19 8:32 ` Ric Mason
2013-02-19 18:56 ` Hugh Dickins
2013-02-19 18:56 ` Hugh Dickins
2013-02-19 18:56 ` Hugh Dickins
2013-02-20 0:40 ` Ric Mason
2013-02-20 0:40 ` Ric Mason
2013-02-20 0:40 ` Ric Mason
2013-03-06 5:34 ` Li Haifeng
2013-03-06 5:34 ` Li Haifeng
2013-03-06 5:34 ` Li Haifeng
2013-03-06 11:04 ` Ric Mason
2013-03-06 11:04 ` Ric Mason
2013-03-06 11:04 ` Ric Mason
2013-03-06 11:10 ` Ric Mason
2013-03-06 11:10 ` Ric Mason
2013-03-06 11:10 ` Ric Mason
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