On Wed, 2007-07-25 at 13:19 +0200, Nick Piggin wrote: > Hi, > > Does this patch solve the X problem? Does anyone see anything wrong > with it or know why agp was locking the pages?
We need to do a little bit of auditing here, but I suspect it will turn out all right. I think the reason it locked them in the first place was to avoid AGP pages mapped into process space from being swapped out. I think that should be taken care of by appropriate vma flags nowadays, but we need to double check. It also might have been a way around dodgy refcounting at one point but I think we got that right nowadays (I remember fixing issues in that area when we removed PageReserved from those pages back then). Ben. > -- > AGP should not need to lock pages. They are not protecting any race > because there is no lock_page calls, only SetPageLocked. > > This is causing hangs with d00806b183152af6d24f46f0c33f14162ca1262a. > > Signed-off-by: Nick Piggin <[EMAIL PROTECTED]> > > diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c > index d535c40..3db4f40 100644 > --- a/drivers/char/agp/generic.c > +++ b/drivers/char/agp/generic.c > @@ -1170,7 +1170,6 @@ void *agp_generic_alloc_page(struct agp_ > map_page_into_agp(page); > > get_page(page); > - SetPageLocked(page); > atomic_inc(&agp_bridge->current_memory_agp); > return page_address(page); > } > @@ -1187,7 +1186,6 @@ void agp_generic_destroy_page(void *addr > page = virt_to_page(addr); > unmap_page_from_agp(page); > put_page(page); > - unlock_page(page); > free_page((unsigned long)addr); > atomic_dec(&agp_bridge->current_memory_agp); > } > diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c > index a124060..2f319f4 100644 > --- a/drivers/char/agp/intel-agp.c > +++ b/drivers/char/agp/intel-agp.c > @@ -213,7 +213,6 @@ static void *i8xx_alloc_pages(void) > } > global_flush_tlb(); > get_page(page); > - SetPageLocked(page); > atomic_inc(&agp_bridge->current_memory_agp); > return page_address(page); > } > @@ -229,7 +228,6 @@ static void i8xx_destroy_pages(void *add > change_page_attr(page, 4, PAGE_KERNEL); > global_flush_tlb(); > put_page(page); > - unlock_page(page); > __free_pages(page, 2); > atomic_dec(&agp_bridge->current_memory_agp); > } > diff --git a/drivers/char/agp/sgi-agp.c b/drivers/char/agp/sgi-agp.c > index cda608c..98cf8ab 100644 > --- a/drivers/char/agp/sgi-agp.c > +++ b/drivers/char/agp/sgi-agp.c > @@ -51,7 +51,6 @@ static void *sgi_tioca_alloc_page(struct > return NULL; > > get_page(page); > - SetPageLocked(page); > atomic_inc(&agp_bridge->current_memory_agp); > return page_address(page); > } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
