From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Date: Tue, 01 May 2007 10:00:19 +1000 > > > > Interesting - thanks for working that out. Let's keep linux-mm on cc please. > > > > You can't elide the update_mmu_cache() call on sun4c because that will > > miss some critical TLB setups which are performed there. > > > > The sun4c TLB has two tiers of entries: > > > > 1) segment maps, these hold ptes for a range of addresses > > 2) ptes, mapped into segment maps > > > > update_mmu_cache() on sun4c take care of allocating and setting > > up the segment maps, so if you elide the call this never happens > > and we fault forever. > > Maybe we can move that logic to ptep_set_access_flags()... in fact, the > tlb flush logic should be done there too imho. > > There would still be the update_mmu_cache() that we don't want on > powerpc in all cases I suppose. That can be done by having > ptep_set_access_flags() return a boolean indicating wether > update_mmu_cache() shall be called or not ... Always doing ptep_set_access_flags() and returning a boolean like that might be a good idea. - To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
