Re: [PATCH] mm: moving dirty pages balancing to pdfludh entirely

From: Nikita Danilov
Date: Wed Jul 05 2006 - 11:00:11 EST


Ananiev, Leonid I writes:
> Nikita Danilov writes:
> > suppose you have more than MAX_PDFLUSH_THREADS
> Do you consider that the drawback of the patch is in that the value
> MAX_PDFLUSH_THREADS is not well known high or this limit is not deleted

I am more concerned, that this patch _limits_ maximal possible writeback
concurrency to MAX_PDFLUSH_THREADS.

> at all? The limit could be deleted after patching because the line

That sounds a bit too extreme, given that pdflush is used for a lot of
things other than background write-out.

> + if (writeback_in_progress(bdi)) {
> keeps off creating extra pdflush threads.

What about replacing

pdflush_operation(background_writeout, 0);

with

if (pdflush_operation(background_writeout, 0))
/*
* Fall back to synchronous writeback if all pdflush
* threads are busy.
*/
writeback_inodes(&wbc);

? This will combine increased concurrency in your target case (single
writer) with some safety net in the case of multiple writers and
multiple devices.

>
> Leonid

Nikita.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/