Re: [patch] mm: speedup in __early_pfn_to_nid

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 03/24/2013 04:37 AM, Yinghai Lu wrote:
> +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
> +int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
> +			 unsigned long *start_pfn, unsigned long *end_pfn)
> +{
> +	struct memblock_type *type = &memblock.memory;
> +	int mid = memblock_search(type, (phys_addr_t)pfn << PAGE_SHIFT);

I'm really eager to see how much time can we save using binary search compared to
linear search in this case :)

(quote)
> A 4 TB (single rack) UV1 system takes 512 seconds to get through
> the zone code.  This performance optimization reduces the time
> by 189 seconds, a 36% improvement.
>
> A 2 TB (single rack) UV2 system goes from 212.7 seconds to 99.8 seconds,
> a 112.9 second (53%) reduction.
(quote)

thanks,
linfeng

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]