Re: [PATCH 1/8] block: limit default readahead size for small devices
From: Christoph Hellwig <hch@infradead.org>
Date: 2011-11-21 10:00:08
Also in:
linux-fsdevel, lkml
From: Christoph Hellwig <hch@infradead.org>
Date: 2011-11-21 10:00:08
Also in:
linux-fsdevel, lkml
On Mon, Nov 21, 2011 at 05:18:20PM +0800, Wu Fengguang wrote:
This looks reasonable: smaller device tend to be slower (USB sticks as well as micro/mobile/old hard disks). Given that the non-rotational attribute is not always reported, we can take disk size as a max readahead size hint. This patch uses a formula that generates the following concrete limits:
Given that you mentioned the rotational flag and device size in this mail, as well as benchmarking with an intel SSD - did you measure how useful large read ahead sizes still are with highend Flash device that have extremly high read IOP rates? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>