Re: Discard support (was Re: [PATCH] swap: send callback when swap slot is freed)

Mark Lord
2009-08-17T20:19:42Z

James Bottomley wrote:
> On Mon, 2009-08-17 at 14:21 -0400, Greg Freemyer wrote:
>> On Mon, Aug 17, 2009 at 1:19 PM, James Bottomley<James.Bottomley@suse.de> wrote:
>>> On Mon, 2009-08-17 at 13:08 -0400, Greg Freemyer wrote:
..
>>>> Non-coalescing is believed detrimental,
>>> It is? Why?
>> For the only compliant SSD in the wild, Mark has shown it to be true
>> via testing.
>
> He only said larger trims take longer. As I said previously, if it's a
> X+nY relationship, then we still benefit from accumulation up to some
> value of n.
..

Err, what I said was, "rm -rf /usr/src/linux" takes over half an hour
with uncoalesced TRIM, and only a scant few seconds in total *with*
coalesced TRIM.