On Tue, Jul 03, 2007 at 08:23:07AM +0200, Oliver Neukum wrote: > Am Dienstag, 3. Juli 2007 schrieb Greg KH: > > On Mon, Jul 02, 2007 at 10:33:12PM -0700, Yinghai Lu wrote: > > > On 7/2/07, Greg KH <[EMAIL PROTECTED]> wrote: > > > > On Mon, Jul 02, 2007 at 03:36:37PM -0700, Yinghai Lu wrote: > > > > > [PATCH 3/4] usb: allocated usb releated dma buffer with kmalloc_node > > > > > > > > > > For amd64 based two way system. USB always on node0. but dma buffer > > > > > for > > > > urb > > > > > allocated via kmalloc always get ram on node1. So change to > > > > > kmalloc_node > > > > to > > > > > get dma_buffer on corresponding node > > > > > > > > Are all of these changes really necessary? You are doing this for some > > > > allocations that take a _long_ time when sending to the device due to > > > > the speed of the device. > > > > > > > > I could possibly see this making a difference on some drivers, but for > > > > the core, and for the basic USB structures, I can't imagine it is really > > > > worth it. > > > > > > > > Or do you have numbers showing the differences here? > > > > > > > > Patch included fully below for the benifit of the usb list, which you > > > > should have cc:ed... > > > > > > dma buffer could be allocated via alloc_pages_coherent. or > > > kmalloc/dma_map_single. > > > alloc_pages_coherent get the dma_buffer on corresponding node. > > > but kmalloc/dma_map_single always get dma_buffer on last node. or say > > > device is on HT chain node0, it will get dma buffer on node 7 of 8 > > > socket system. > > > also on two way system with 4G+4G RAM conf. device on node 0 will get > > > dma_buffer above 4G, and if the dma_mask is less 32bit, will need > > > extra iommu mapping. > > > In my mcp55+io55 system, it show dma_map_single is keepping called by > > > usb input: keyboard/mouse (8/0x40 bytes), and forcedeth. (0x670bytes) > > > > Ok, so two drivers might need this, but not the whole usb core, right? > > If those two drivers need the extended allocator, why not use it where > it is beneficial, even if the benefit is small?
What is the benefit? Speed isn't an issue here, so what is? thanks, greg k-h ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
