From: David Rientjes <rientjes@google.com>
To: Dave Hansen <dave@sr71.net>
Cc: Christoph Lameter <cl@linux.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, penberg@kernel.org
Subject: Re: [RFC][PATCH 3/9] mm: page->pfmemalloc only used by slab/skb
Date: Tue, 14 Jan 2014 18:45:38 -0800 (PST) [thread overview]
Message-ID: <alpine.DEB.2.02.1401141842220.32645@chino.kir.corp.google.com> (raw)
In-Reply-To: <52D5B762.3090209@sr71.net>
On Tue, 14 Jan 2014, Dave Hansen wrote:
> >> page->pfmemalloc does not deserve a spot in 'struct page'. It is
> >> only used transiently _just_ after a page leaves the buddy
> >> allocator.
> >
> > Why would we need to do this if we are removing the cmpxchg_double?
>
> Why do we need the patch?
>
> 'struct page' is a mess. It's really hard to follow, and the space in
> the definition is a limited resource. We should not waste that space on
> such a transient and unimportant value as pfmemalloc.
>
I don't have any strong opinions on whether this patch is merged or not,
but I'm not sure it's cleaner to do it with an accessor function that
overloads page->index when its placement within the union inside
struct page makes that obvious, nor is it good that the patch adds more
code than it removes solely because it introduces those accessor
functions.
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next prev parent reply other threads:[~2014-01-15 2:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-14 18:00 [RFC][PATCH 0/9] re-shrink 'struct page' when SLUB is on Dave Hansen
2014-01-14 18:00 ` [RFC][PATCH 1/9] mm: slab/slub: use page->list consistently instead of page->lru Dave Hansen
2014-01-14 19:31 ` Christoph Lameter
2014-01-15 2:31 ` David Rientjes
2014-01-15 6:58 ` Dave Hansen
2014-01-15 7:16 ` David Rientjes
2014-01-16 0:11 ` Kirill A. Shutemov
2014-01-14 18:00 ` [RFC][PATCH 2/9] mm: slub: abstract out double cmpxchg option Dave Hansen
2014-01-14 19:49 ` Christoph Lameter
2014-01-14 21:41 ` Dave Hansen
2014-01-15 2:37 ` David Rientjes
2014-01-16 16:45 ` Christoph Lameter
2014-01-16 17:13 ` Dave Hansen
2014-01-14 18:00 ` [RFC][PATCH 3/9] mm: page->pfmemalloc only used by slab/skb Dave Hansen
2014-01-14 19:49 ` Christoph Lameter
2014-01-14 22:17 ` Dave Hansen
2014-01-15 2:45 ` David Rientjes [this message]
2014-01-16 0:16 ` Kirill A. Shutemov
2014-01-14 18:00 ` [RFC][PATCH 4/9] mm: slabs: reset page at free Dave Hansen
2014-01-15 2:48 ` David Rientjes
2014-01-16 18:35 ` Dave Hansen
2014-01-16 18:32 ` Christoph Lameter
2014-01-14 18:00 ` [RFC][PATCH 5/9] mm: rearrange struct page Dave Hansen
2014-01-16 0:20 ` Kirill A. Shutemov
2014-01-16 18:34 ` Christoph Lameter
2014-01-16 22:29 ` Dave Hansen
2014-01-17 14:58 ` Christoph Lameter
2014-01-14 18:01 ` [RFC][PATCH 6/9] mm: slub: rearrange 'struct page' fields Dave Hansen
2014-01-14 18:01 ` [RFC][PATCH 7/9] mm: slub: remove 'struct page' alignment restrictions Dave Hansen
2014-01-14 18:01 ` [RFC][PATCH 8/9] mm: slub: cleanups after code churn Dave Hansen
2014-01-14 18:01 ` [RFC][PATCH 9/9] mm: fix alignment checks on 32-bit Dave Hansen
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