Re: [patch] mm: Convert global dirty_exceeded flag to per-node node_dirty_exceeded

[Andrew Morton <akpm@osdl.org>]

Ravikiran G Thirumalai <kiran@scalex86.org> wrote:
>
> > OK.  That's a bit nasty, isn't it?  It can work well or poorly for
> > different people depending upon vagaries of .config and the linker.
> > 
> > We should find out what it was sharing _with_.  Could you please run
> > 
> > 	nm -n vmlinux| grep -C5 dirty_exceeded
> 
> ffffffff805290c0 b irq_dir
> ffffffff80529838 b root_irq_dir
> ffffffff80529880 B max_pfn
> ffffffff80529888 B min_low_pfn
> ffffffff80529890 B max_low_pfn
> ffffffff80529900 B nr_pagecache
> ffffffff80529908 B nr_swap_pages
> ffffffff80529980 b boot_pageset
> ffffffff8052a980 B laptop_mode
> ffffffff8052a984 B block_dump
> ffffffff8052a988 b dirty_exceeded
> ffffffff8052a990 b total_pages
> ffffffff8052a998 B nr_pdflush_threads
> ffffffff8052a9a0 b last_empty_jifs
> ffffffff8052a9c0 B slab_reclaim_pages
> ffffffff8052a9c4 b slab_break_gfp_order
> ffffffff8052a9c8 b g_cpucache_up
> ffffffff8052a9d0 b cache_chain
> ffffffff8052a9e0 b cache_chain_sem
> ffffffff8052aa00 b offslab_limit
> ffffffff8052aa08 B page_cluster
> 
> Maybe slab_reclaim_pages is the culprit? 
> 

I guess so - pretty much everything else there should be in __read_mostly
anwyay, apart from nr_pagecache.

slab_reclaim_pages is just a silly beancounting thing for overcommit.  We
could give it the approximate-counting treatment like pagecache_acct() I
guess.