From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: vm_ops.page_mkwrite() fails with vmalloc on 2.6.23 From: Stefani Seibold Reply-To: stefani@seibold.net In-Reply-To: <1193738177.27652.69.camel@twins> References: <1193064057.16541.1.camel@matrix> <20071029004002.60c7182a.akpm@linux-foundation.org> <45a44e480710290117u492dbe82ra6344baf8bb1e370@mail.gmail.com> <1193677302.27652.56.camel@twins> <45a44e480710291051s7ffbb582x64ea9524c197b48a@mail.gmail.com> <1193681839.27652.60.camel@twins> <1193696211.5644.100.camel@lappy> <45a44e480710291822w5864b3beofcf432930d3e68d3@mail.gmail.com> <1193738177.27652.69.camel@twins> Content-Type: text/plain Date: Tue, 30 Oct 2007 11:49:16 +0100 Message-Id: <1193741356.13775.2.camel@matrix> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: Jaya Kumar , Andrew Morton , linux-kernel@vger.kernel.org, David Howells , linux-mm@kvack.org, Hugh Dickins List-ID: Hi, the question is how can i get all pte's from a vmalloc'ed memory. Due to the zeroed mapping pointer i dont see how to do this? Am Dienstag, den 30.10.2007, 10:56 +0100 schrieb Peter Zijlstra: > On Mon, 2007-10-29 at 21:22 -0400, Jaya Kumar wrote: > > On 10/29/07, Peter Zijlstra wrote: > > > > > > [ also, remap_vmalloc_range() suffers similar issues, only file and anon > > > have proper rmap ] > > > > > > I'm not sure we want full rmap for remap_pfn/vmalloc_range, but perhaps > > > we could assist drivers in maintaining and using vma lists. > > > > > > I think page_mkclean_one() would work if you'd manually set page->index > > > and iterate the vmas yourself. Although atm I'm not sure of anything so > > > don't pin me on it. > > > > :-) If it's anybody's fault, it's mine for not testing properly. My bad. > > > > In the case of defio, I think it's no trouble to build a list of vmas > > at mmap time and then to iterate through them when it's ready for > > mkclean time as you suggested. I don't fully understand page->index > > yet. I had thought it was only used by swap cache or file map. > > > > On an unrelated note, I was looking for somewhere to stuff a 16 bit > > offset (so that I have a cheap way to know which struct page > > corresponds to which framebuffer block or offset) for another driver. > > I had thought page->index was it but I think I am wrong now. > Yeah, page->index is used along with vma->vmpgoff and vma->vm_start to > determine the address of the page in the given vma: > > address = vma->vm_start + ((page->index - vma->vm_pgoff) << PAGE_SHIFT); > > and from that address the pte can be found by walking the vma->vm_mm > page tables. > > So page->index does what you want it to, identify which part of the > framebuffer this particular page belongs to. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org