Messages in this thread |  | | Date | Fri, 29 Sep 2000 17:49:04 -0600 | From | "Jeff V. Merkey" <> | Subject | Re: reading 1 hardsector size, not one block size |
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Al,
This is going to be a continuing problem for non-Unix file systems like NTFS and NWFS that rely on the ability to read and write variable length sector runs. At some point, the AIO subsystem needs to get fixed. I submitted a patch based on Linus' suggestion that the check in ll_rw_block() be removed to allow folks to chain variable length sector requests. After I did, half the disk drivers seemed to croak and break. I doubt 2.4 could be changed, but 2.5 needs this or it's going to keep biting. The whole buffer head chaining crap is too memory intensive.
How about
<disk, starting sector, sector count, callback> for the request? Forcing us to use a 512 byte block size sucks up tons of memory and creates too much overhead to get high performance numbers. I notice very significant performance differences when using 512 blocks in NWFS and EXT2 with 1024 and 4K block sizes.
Jeff
Alexander Viro wrote: > > On Sat, 30 Sep 2000, Anton Altaparmakov wrote: > > > All those problems disappear as soon as you change BLOCK_SIZE to 512. And > > Have you actually tried that? Go ahead, just do full backup before the > experiment... > > - > 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/ - 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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