Re: Page Fault Scalability patch V19 [4/4]: Drop use ofpage_table_lock in do_anonymous_page

[Andi Kleen]

Christoph Lameter <clameter@xxxxxxx> writes:

> Do not use the page_table_lock in do_anonymous_page. This will significantly
> increase the parallelism in the page fault handler in SMP systems. The patch
> also modifies the definitions of _mm_counter functions so that rss and anon_rss
> become atomic.

I still think it's a bad idea to add arbitary process size limits like this:

>  
> +#ifdef CONFIG_ATOMIC_TABLE_OPS
> +/*
> + * Atomic page table operations require that the counters are also
> + * incremented atomically
> +*/
> +#define set_mm_counter(mm, member, value) atomic_set(&(mm)->member, value)
> +#define get_mm_counter(mm, member) ((unsigned long)atomic_read(&(mm)->member))
> +#define update_mm_counter(mm, member, value) atomic_add(value, &(mm)->member)
> +#define MM_COUNTER_T atomic_t

Can you use atomic64_t on 64bit systems at least? 

-Andi
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