Re: [RFC][PATCH 5/7] writeback: use 64MB MAX_WRITEBACK_PAGES

Theodore Tso
2009-09-09T23:30:05Z

On Wed, Sep 09, 2009 at 10:51:46PM +0800, Wu Fengguang wrote:
> + * The maximum number of pages to writeout in a single periodic/background
> + * writeback operation. 64MB means I_SYNC may be hold for up to 1 second.
> + * This is not a big problem since we normally do kind of trylock on I_SYNC
> + * for non-data-integrity writes. Userspace tasks doing throttled writeback
> + * do not use this value.

What's your justification for using 64MB? Where are you getting 1
second from? On a fast RAID array 64MB can be written in much less
than 1 second.

More generally, I assume your patches conflict with Jens' per-bdi patches?

- Ted