* Dave Hansen ([EMAIL PROTECTED]) wrote: > On Thu, 2007-11-15 at 16:51 -0500, Mathieu Desnoyers wrote: > > * Dave Hansen ([EMAIL PROTECTED]) wrote: > > > > On Tue, 2007-11-13 at 14:33 -0500, Mathieu Desnoyers wrote: > > > > linux-2.6-lttng/mm/page_io.c 2007-11-13 09:49:35.000000000 -0500 > > > > @@ -114,6 +114,7 @@ int swap_writepage(struct page *page, st > > > > rw |= (1 << BIO_RW_SYNC); > > > > count_vm_event(PSWPOUT); > > > > set_page_writeback(page); > > > > + trace_mark(mm_swap_out, "address %p", page_address(page)); > > > > unlock_page(page); > > > > submit_bio(rw, bio); > > > > out: > > > > > > I'm not sure all this page_address() stuff makes any sense on highmem > > > systems. How about page_to_pfn()? > > > > Knowing which page frame number has been swapped out is not always as > > relevant as knowing the page's virtual address (when it has one). Saving > > both the PFN and the page's virtual address could give us useful > > information when the page is not mapped. > > For most (all?) architectures, the PFN and the virtual address in the > kernel's linear are interchangeable with pretty trivial arithmetic. All > pages have a pfn, but not all have a virtual address. Thus, I suggested > using the pfn. What kind of virtual addresses are you talking about? >
Hrm, in asm-generic/memory_model.h, we have various versions of __page_to_pfn. Normally they all cast the result to (unsigned long), except for : #elif defined(CONFIG_SPARSEMEM_VMEMMAP) /* memmap is virtually contigious. */ #define __pfn_to_page(pfn) (vmemmap + (pfn)) #define __page_to_pfn(page) ((page) - vmemmap) So I guess the result is a pointer ? Should this be expected ? Mathieu -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - 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/
