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? And even if you do have another usb mapping, is that a real problem? USB keyboards and mice are very slow. 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
