"Stephen C. Tweedie" wrote:

Hi,

On Fri, 07 Jan 2000 00:32:48 +0300, Hans Reiser [off-list ref] said:

quoted

Andrea Arcangeli wrote:

quoted

BTW, I thought Hans was talking about places that can't sleep (because of
some not schedule-aware lock) when he said "place that cannot call
balance_dirty()".

quoted

You were correct.  I think Stephen and I are missing in communicating here.

Fine, I was just looking at it from the VFS point of view, not the
specific filesystem.  In the worst case, a filesystem can always simply
defer marking the buffer as dirty until after the locking window has
passed, so there's obviously no fundamental problem with having a
blocking mark_buffer_dirty.  If we want a non-blocking version too, with
the requirement that the filesystem then to a manual rebalance once it
is safe to do so, that will work fine too.

--Stephen

Yes, but then you have to track what you defer.  Code complication.

I just want to leave things as they are until we have time to do SMP right.

When we do SMP right, then a mark_buffer_dirty() which causes schedule is not a
problem.  Let's deal with this in 2.5....

Hans

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