Messages in this thread |  | | Date | Wed, 7 Feb 2001 00:36:29 +0000 | From | "Stephen C. Tweedie" <> | Subject | Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait |
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Hi,
On Tue, Feb 06, 2001 at 07:25:19PM -0500, Ingo Molnar wrote: > > On Wed, 7 Feb 2001, Stephen C. Tweedie wrote: > > > No, it is a problem of the ll_rw_block interface: buffer_heads need to > > be aligned on disk at a multiple of their buffer size. Under the Unix > > raw IO interface it is perfectly legal to begin a 128kB IO at offset > > 512 bytes into a device. > > then we should either fix this limitation, or the raw IO code should split > the request up into several, variable-size bhs, so that the range is > filled out optimally with aligned bhs.
That gets us from 512-byte blocks to 4k, but no more (ll_rw_block enforces a single blocksize on all requests but that relaxing that requirement is no big deal). Buffer_heads can't deal with data which spans more than a page right now.
--Stephen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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