Messages in this thread | | | Date | Thu, 14 Sep 2006 15:40:55 -0700 | From | "Darrick J. Wong" <> | Subject | Re: [PATCH v3] libsas: move ATA bits into a separate module |
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Jeff Garzik wrote:
> I disagree completely with this approach. > > You don't need a table of hooks for the case where libata is disabled in > .config. Thus, it's only useful for the case where libsas is loaded as > a module, but libata is not.
Indeed, I misunderstood what James Bottomley wanted, so I reworked the patch. It has the same functionality as before, but this module uses the module loader/symbol resolver for all the functions in libata, and allows libsas to (optionally) call into sas_ata with weak references by pushing a table of the necessary function pointers into libsas at sas_ata load time. Thus, libsas doesn't need to load libata/sas_ata unless it actually finds a SATA device.
> The libsas code should directly call libata functions. If ATA support > in libsas is disabled in .config, then those functions will never be > called, thus never loaded the libata module.
I certainly can (and now do) call libata functions from sas_ata. However, there are a few cases where libsas needs to call libata (ex. sas_ioctl); for those cases, I think the function pointers are still necessary because I don't want to make libsas require libata. In any case, if ATA support is disabled in .config, sata_is_dev always returns 0, so the dead-code eliminator should zap that out of libsas entirely.
As usual, thank you for any feedback that you have.
Link to version 3: http://sweaglesw.net/~djwong/docs/sas-ata_3.patch
--D
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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