Re: [PATCH] laptop mode

[Jeff Garzik <jgarzik@pobox.com>]

Jens Axboe wrote:
> On Thu, Oct 09 2003, Marcelo Tosatti wrote:
> 
>>
>>On Thu, 9 Oct 2003, Jeff Garzik wrote:
>>
>>
>>>Linux Kernel Mailing List wrote:
>>>
>>>>ChangeSet 1.1150.1.52, 2003/10/08 10:49:45-03:00, axboe@suse.de
>>>>
>>>>	[PATCH] laptop mode
>>>>	
>>>>	Hi Marcelo,
>>>>	
>>>>	Lots of people have been using this patch with great success, and it's
>>>>	been in the SuSE kernel for some months now too. It is also in the -benh
>>>>	ppc tree
>>>>	
>>>>	Basically, it introduces a write back mode of dirty and journal data
>>>>	that is more suitable for laptops. At the block layer end, it schedules
>>>>	write out of dirty data after the disk has been idle for 5 seconds.
>>>>	
>>>>	Laptop mode can be switched on and off with /proc/sys/vm/laptop_mode.
>>>>	There is also a block_dump sysctl, which if enabled will dump who
>>>>	dirties and writes out data. This is very helpful in pinning down who is
>>>>	causing unnecessary writes to the disk.
>>>
>>>Red Hat just dropped this patch since it was suspected of data 
>>>corruption ;-(
>>
>>Uh, oh... Jens? 
> 
> 
> See my previous mail. I don't see any problems with it, and I've
> certainly not heard of (or experienced myself) problems with the patch.
> I'm waiting for Jeff to expand on his mail, surely he/RH must know more
> about this issue.


That's 100% of my knowledge.  Talk to arjan/davej/sct for more info...

That's what RH's field testing showed us, ignore it if you wish... :)

	Jeff