Dear Jan > -----Original Message----- > From: Jan Beulich [mailto:JBeulich@xxxxxxxx] > Sent: Tuesday, February 17, 2015 6:09 PM > To: Wang, Xiaoming > Cc: chris@xxxxxxxxxxxxxxxxxx; david.vrabel@xxxxxxxxxx; > lauraa@xxxxxxxxxxxxxx; heiko.carstens@xxxxxxxxxx; linux@xxxxxxxxxxx; > Liu, Chuansheng; Zhang, Dongxing; takahiro.akashi@xxxxxxxxxx; > akpm@xxxxxxxxxxxxxxxxxxxx; linux-mips@xxxxxxxxxxxxxx; ralf@linux- > mips.org; xen-devel@xxxxxxxxxxxxxxxxxxxx; boris.ostrovsky@xxxxxxxxxx; > konrad.wilk@xxxxxxxxxx; d.kasatkin@xxxxxxxxxxx; pebolle@xxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [Xen-devel] [PATCH v4] modify the IO_TLB_SEGSIZE and > IO_TLB_DEFAULT_SIZE configurable as flexible requirement about SW- > IOMMU. > > >>> On 17.02.15 at 07:51, <xiaoming.wang@xxxxxxxxx> wrote: > > --- a/Documentation/kernel-parameters.txt > > +++ b/Documentation/kernel-parameters.txt > > @@ -3438,10 +3438,12 @@ bytes respectively. Such letter suffixes can > > also be entirely omitted. > > it if 0 is given (See > Documentation/cgroups/memory.txt) > > > > swiotlb= [ARM,IA-64,PPC,MIPS,X86] > > - Format: { <int> | force } > > + Format: { <int> | force | <int> | <int>} > > <int> -- Number of I/O TLB slabs > > force -- force using of bounce buffers even if they > > wouldn't be automatically used by the kernel > > + <int> -- Maximum allowable number of contiguous > slabs to map > > + <int> -- The size of SW-MMU mapped. > > This makes no sense - the new numbers added aren't position independent > (nor were the previous <int> and "force"). > Use "," can separate them one by one. We do it at lib/swiotlb.c > Also you are (supposedly) removing all uses of IO_TLB_DEFAULT_SIZE, yet > you don't seem to remove the definition itself. > I have change all uses of IO_TLB_DEFAULT_SIZE to io_tlb_default_size in lib/swiotlb.c > Finally - are arbitrary numbers really okay for the newly added command line > options? I.e. shouldn't you add some checking of their validity? > I have validity these code is OK. Example: BOARD_KERNEL_CMDLINE += swiotlb=, ,512,268435456 Io_tlb_segsize has been changed from 128 to 512 Io_tlb_default_size has been changed from 64M to 268435456 (256M) > Jan Xiaoming.
