Dear David > -----Original Message----- > From: David Vrabel [mailto:david.vra...@citrix.com] > Sent: Tuesday, February 10, 2015 5:46 PM > To: Wang, Xiaoming; Konrad Rzeszutek Wilk > Cc: linux-m...@linux-mips.org; pebo...@tiscali.nl; Zhang, Dongxing; > lau...@codeaurora.org; d.kasat...@samsung.com; > heiko.carst...@de.ibm.com; linux-ker...@vger.kernel.org; ralf@linux- > mips.org; ch...@chris-wilson.co.uk; takahiro.aka...@linaro.org; > david.vra...@citrix.com; li...@horizon.com; xen- > de...@lists.xenproject.org; boris.ostrov...@oracle.com; Liu, Chuansheng; > a...@linux-foundation.org > Subject: Re: [Xen-devel] [PATCH] modify the IO_TLB_SEGSIZE to > io_tlb_segsize configurable as flexible requirement about SW-IOMMU. > > On 06/02/15 00:10, Wang, Xiaoming wrote: > > > > > >> -----Original Message----- > >> From: Konrad Rzeszutek Wilk [mailto:konrad.w...@oracle.com] > >> Sent: Friday, February 6, 2015 3:33 AM > >> To: Wang, Xiaoming > >> Cc: r...@linux-mips.org; boris.ostrov...@oracle.com; > >> david.vra...@citrix.com; linux-m...@linux-mips.org; linux- > >> ker...@vger.kernel.org; xen-de...@lists.xenproject.org; akpm@linux- > >> foundation.org; li...@horizon.com; lau...@codeaurora.org; > >> heiko.carst...@de.ibm.com; d.kasat...@samsung.com; > >> takahiro.aka...@linaro.org; ch...@chris-wilson.co.uk; > >> pebo...@tiscali.nl; Liu, Chuansheng; Zhang, Dongxing > >> Subject: Re: [PATCH] modify the IO_TLB_SEGSIZE to io_tlb_segsize > >> configurable as flexible requirement about SW-IOMMU. > >> > >> On Fri, Feb 06, 2015 at 07:01:14AM +0800, xiaomin1 wrote: > >>> The maximum of SW-IOMMU is limited to 2^11*128 = 256K. > >>> While in different platform and different requirements this seems > improper. > >>> So modify the IO_TLB_SEGSIZE to io_tlb_segsize as configurable is > >>> make > >> sense. > >> > >> More details please. What is the issue you are hitting? > >> > > Example: > > If 1M bytes are requied. There has an error like. > > Instead of allowing the bouncing of such large buffers, could the gadget > driver be modified to submit the buffers to the hardware in smaller chunks? > > David
Our target is try to make IO_TLB_SEGSIZE configurable. Neither 256 bytes or 1M bytes seems suitable value, I think. It's better to use the tactics something like kmem_cache_create in kmalloc function. But SW-IOMMU seems more lighter. So we choose variable rather than function. Xiaoming. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
