On Wed, 03 Feb 2010 12:00:58 -0500 Jeff Garzik <jgarzik@xxxxxxxxx> wrote: > On 02/03/2010 11:40 AM, James Bottomley wrote: > > The fix to libata looks to be just that it should kmap all the time > > rather than trying to fiddle with the page to see if its higmem. For > > kmap on a normal page, we should just return the offset map address and > > do all the flushing. > > libata tests PageHighMem() because it was measurably faster to do things > the current way (which includes local_irq_save/restore, only for > highmem) on boxes where it actually matters. > > It seems more efficient to add a flush where necessary, than > unconditionally punish everyone... kmap_atomic() tests PageHighMem() too - it's pretty lightweight for lowmem pages. Anyway, I'd draw your attention to this claim in the changelog: "This patch allows the ARM boards to use a rootfs on CompactFlash with the PATA platform driver." Immediate-term, we should be looking for a small fix for this issue which is acceptable for 2.6.33 and 2.6.32 and earlier. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
