Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1537866

Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7

Show all headers | View raw

On Wed, Dec 07, 2016 at 08:52:27AM -0600, Christoph Lameter wrote:
> On Wed, 7 Dec 2016, Mel Gorman wrote:
> 
> > SLUB has been the default small kernel object allocator for quite some time
> > but it is not universally used due to performance concerns and a reliance
> > on high-order pages. The high-order concerns has two major components --
> 
> SLUB does not rely on high order pages. It falls back to lower order if
> the higher orders are not available. Its a performance concern.
> 

Ok -- While SLUB does not rely on high-order pages for functional
correctness, it perfoms better if high-order pages are available.

> This is also an issue for various other kernel subsystems that really
> would like to have larger contiguous memory area. We are often seeing
> performance constraints due to the high number of 4k segments when doing
> large scale block I/O f.e.
> 

Which is related to the fundamentals of fragmentation control in
general. At some point there will have to be a revisit to get back to
the type of reliability that existed in 3.0-era without the massive
overhead it incurred. As stated before, I agree it's important but
outside the scope of this patch.

-- 
Mel Gorman
SUSE Labs

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-07 11:20 +0100
  Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Christoph Lameter <cl@linux.com> - 2016-12-07 16:00 +0100
    Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-07 17:00 +0100
      Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Christoph Lameter <cl@linux.com> - 2016-12-07 17:50 +0100
        Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-07 17:50 +0100
          Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Christoph Lameter <cl@linux.com> - 2016-12-07 18:20 +0100
            Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-07 18:40 +0100
  Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Eric Dumazet <eric.dumazet@gmail.com> - 2016-12-07 20:10 +0100
    Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Eric Dumazet <eric.dumazet@gmail.com> - 2016-12-07 20:20 +0100
    Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-07 20:50 +0100
      Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Eric Dumazet <eric.dumazet@gmail.com> - 2016-12-07 21:20 +0100
        Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-07 22:30 +0100
          Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-08 00:30 +0100
            Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Jesper Dangaard Brouer <brouer@redhat.com> - 2016-12-08 09:30 +0100
              Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-08 10:20 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Jesper Dangaard Brouer <brouer@redhat.com> - 2016-12-08 11:50 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-08 12:10 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Jesper Dangaard Brouer <brouer@redhat.com> - 2016-12-08 15:50 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-08 16:20 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Jesper Dangaard Brouer <brouer@redhat.com> - 2016-12-08 18:30 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Mel Gorman <mgorman@techsingularity.net> - 2016-12-08 18:40 +0100
                Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7 Eric Dumazet <eric.dumazet@gmail.com> - 2016-12-08 17:10 +0100

csiph-web