Hi Konrad, On 24/06/16 11:46, Konrad Rzeszutek Wilk wrote: > On Fri, Jun 24, 2016 at 10:57:29AM +0800, Jisheng Zhang wrote: >> Dear Konrad, >> >> On Thu, 23 Jun 2016 12:06:10 -0400 Konrad Rzeszutek Wilk wrote: >> >>> On June 23, 2016 10:30:34 AM EDT, Catalin Marinas <catalin.marinas@xxxxxxx> wrote: >>>> On Thu, Jun 23, 2016 at 05:43:40PM +0530, Manjeet Pawar wrote: >>>>> From: Rohit Thapliyal <r.thapliyal@xxxxxxxxxxx> >>>>> >>>>> swiotlb default size of 64M is too big as >>>>> default value therefore it is made configurable >>>>> through command line through swiotlb_size parameter. >>>>> swiotlb allocation shall be done only when the >>>>> swiotlb size is given through command line. >>>>> Otherwise no swiotlb is allocated. >>>> >>>> I already queued this patch: >>>> >>>> http://lkml.kernel.org/g/1465372426-4077-1-git-send-email-jszhang@xxxxxxxxxxx >>>> >>>> If you have any objections to it, please reply there. >>> >>> >>> I do (sorry about duplicate email, the other got rejected by mailing lists). >>> >>> Why not expand the swiotlb= parameter instead of introducing a new one? >> >> Do you mean pass "swiotlb=" for those platforms(most probably, arm64 with less >> than 4GB DDR) which don't need swiotlb? I'm afraid this is not convenient, and > > Why not just have a function that checks the amount of memory? x86 has > that - if it finds that the machine has less than 4GB it will not setup > SWIOTLB? > >> users even don't notice swiotlb parameter. From another side, pass "swiotlb=0" >> will make the swiotlb reserve 64MB instead, so how can we achieve zero reserved >> memory for swiotlb through "swiotlb=" parameter? > > Obviously make the function understand that 0 is to turn it off. >> >> PS: my patch didn't introduce new boot parameter. > > swiotlb_sz ? Note that Jisheng's patch is the one Catalin linked to, *not* this one, and more or less does exactly what you describe. Robin. >> >> I'm not sure I got your meaning, so could you please comment my patch >> directly? >> >> Thanks, >> Jisheng >> >>> >>> Also, why not use the swiotlb by itself? That does the job as well? >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
