From: dave@sr71.net (Dave Hansen)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 3/4] mm/vmalloc.c: Allow lowmem to be tracked in vmalloc
Date: Fri, 15 Nov 2013 07:53:34 -0800 [thread overview]
Message-ID: <5286437E.6040905@sr71.net> (raw)
In-Reply-To: <5285A896.3030204@codeaurora.org>
On 11/14/2013 08:52 PM, Laura Abbott wrote:
> free (ptr) {
> if (is_vmalloc_addr(ptr)
> vfree
> else
> kfree
> }
>
> so my hypothesis would be that any path would have to be willing to take
> the penalty of vmalloc anyway. The actual cost would depend on the
> vmalloc / kmalloc ratio. I haven't had a chance to get profiling data
> yet to see the performance difference.
Well, either that, or these kinds of things where it is a fallback:
> hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
> if (hc == NULL)
> hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@sr71.net>
To: Laura Abbott <lauraa@codeaurora.org>,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org
Cc: Neeti Desai <neetid@codeaurora.org>
Subject: Re: [RFC PATCH 3/4] mm/vmalloc.c: Allow lowmem to be tracked in vmalloc
Date: Fri, 15 Nov 2013 07:53:34 -0800 [thread overview]
Message-ID: <5286437E.6040905@sr71.net> (raw)
In-Reply-To: <5285A896.3030204@codeaurora.org>
On 11/14/2013 08:52 PM, Laura Abbott wrote:
> free (ptr) {
> if (is_vmalloc_addr(ptr)
> vfree
> else
> kfree
> }
>
> so my hypothesis would be that any path would have to be willing to take
> the penalty of vmalloc anyway. The actual cost would depend on the
> vmalloc / kmalloc ratio. I haven't had a chance to get profiling data
> yet to see the performance difference.
Well, either that, or these kinds of things where it is a fallback:
> hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
> if (hc == NULL)
> hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
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next prev parent reply other threads:[~2013-11-15 15:53 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-11 23:26 [RFC 0/4] Intermix Lowmem and vmalloc Laura Abbott
2013-11-11 23:26 ` Laura Abbott
2013-11-11 23:26 ` [RFC PATCH 1/4] arm: mm: Add iotable_init_novmreserve Laura Abbott
2013-11-11 23:26 ` Laura Abbott
2013-11-11 23:26 ` [RFC PATCH 2/4] arm: mm: Track lowmem in vmalloc Laura Abbott
2013-11-11 23:26 ` Laura Abbott
2013-11-11 23:26 ` [RFC PATCH 3/4] mm/vmalloc.c: Allow lowmem to be tracked " Laura Abbott
2013-11-11 23:26 ` Laura Abbott
2013-11-11 23:37 ` Kyungmin Park
2013-11-11 23:37 ` Kyungmin Park
2013-11-12 1:23 ` Laura Abbott
2013-11-12 1:23 ` Laura Abbott
2013-11-14 17:45 ` Dave Hansen
2013-11-14 17:45 ` Dave Hansen
2013-11-15 4:52 ` Laura Abbott
2013-11-15 4:52 ` Laura Abbott
2013-11-15 15:53 ` Dave Hansen [this message]
2013-11-15 15:53 ` Dave Hansen
2013-11-26 22:45 ` Andrew Morton
2013-11-26 22:45 ` Andrew Morton
2013-12-03 4:59 ` Laura Abbott
2013-12-03 4:59 ` Laura Abbott
2013-11-11 23:26 ` [RFC PATCH 4/4] mm/vmalloc.c: Treat the entire kernel virtual space as vmalloc Laura Abbott
2013-11-11 23:26 ` Laura Abbott
2013-11-14 17:26 ` Dave Hansen
2013-11-14 17:26 ` Dave Hansen
2013-11-15 5:34 ` Laura Abbott
2013-11-15 5:34 ` Laura Abbott
2013-11-12 0:13 ` [RFC 0/4] Intermix Lowmem and vmalloc Russell King - ARM Linux
2013-11-12 0:13 ` Russell King - ARM Linux
2013-11-12 1:24 ` Laura Abbott
2013-11-12 1:24 ` Laura Abbott
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