Messages in this thread | | | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: [patch][9/9] block: remove bio walking | Date | Thu, 9 Sep 2004 16:28:25 +0200 |
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On Thursday 09 September 2004 16:04, Russell King wrote: > On Thu, Sep 09, 2004 at 03:53:13PM +0200, Bartlomiej Zolnierkiewicz wrote: > > On Thursday 09 September 2004 10:03, Russell King wrote: > > > On Wed, Sep 08, 2004 at 09:27:04PM +0200, Bartlomiej Zolnierkiewicz wrote: > > > > [patch] block: remove bio walking > > > > > > > > IDE driver was the only user of bio walking code. > > > > was in -bk10 :-( > > > > > The MMC driver also uses this. Please don't remove. > > > > OK I'll just drop this patch but can't we also use scatterlists in MMC? > > > > The point is that I now think bio walking was a mistake and accessing > > bios directly from low-level drivers is a layering violation (thus > > all the added complexity). Moreover with fixed IDE PIO and without > > bio walking code it should be possible to shrink struct request by > > removing all "current" entries. > > I'm wondering whether it is legal to map onto SG lists and then do PIO. > Provided we don't end up using the DMA API and then using PIO to the > original pages, it should work.
Yes, it actually works fine. See the other patches from the patchkit. :-)
While at it: AFAICS libata does pci_[un]map_sg() for PIO which is wrong.
> I would rather Jens considered your point first before rewriting code.
OK
> However, using the SG lists does finally provide us with a nice way to > ensure that we have the right information to finally fix IDE wrt the > PIO cache issues (dirty cache lines being left in the page cache.)
Could you explain the issue a bit more? - 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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