Re: CONFIG_BIGMEM and rawio

Manfred Spraul (manfreds@colorfullife.com)
Sat, 04 Sep 1999 00:34:23 +0200


"Stephen C. Tweedie" wrote:
> There are two different ways forward here.
>
> The quick and easy hack to get raw IO working is to do precisely what
> the swap code does. That works fully synchronously, so it's easy to do.

Since bounce_user_kiobuf() is required anyway, I would prefer this
aproach:
it looks like a 2 line fix.

> [ or: ]
> The harder problem is to
> hide it inside ll_rw_block(), which we _do_ want to do if we move the
> page cache to high memory.

Is that planed for 2.[34]?
If not, then I'd wait: I don't like a large in-advance solution for a
not exactly defined problem [possible OOM problems]

Note that currently, kswapd automagically ignores pages from bigmem if
it cannot allocate the bounce buffer [mm/vmscan.c, line 159]. It will be
difficult to do that in ll_rw_block().

--
	Manfred

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