On 05/14/2012 04:43 PM, mani wrote:

Dear Kim,

I have a query here ..


    My point is that it would be better for read to not preempt
    write-for-page_reclaim.
    And we can identify it by PG_reclaim. You can get the idea.

I think If there is no page available then no read will proceed.

When read request comes it reclaim the pages (starts the write if

syncable pages ) and get back after reclaiming the pages.
Only then a read request will come to the MMC subsystem.

And i think the reclaim algorithm will reclaim some substantial amount

of pages at a time instead of a single page.
So if we get few pages during the reclamation so there will be no
problem in halting the another write ops for proceeding the reads ?

Can we think of a scenario when we are reclaiming the pages and write
ops is going on where as a high priority read for the interrupt handler
is pending ?

Please correct me if i am wrong.

For example, System can have lots of order-0 pages but little order-big pages.
In this case, for getting big contiguos memory, reclaimer should write out
dirty pages while it can handle order-0 page read request.

Thanks & Regards
Manish

-- 
Kind regards,
Minchan Kim