Re: [PATCH v3] x86, kdump: Set crashkernel_low automatically
On 03/18/2013 04:26 PM, Yinghai Lu wrote: > > now only have: > swiotlb overflow buffer > > v_overflow_buffer = alloc_bootmem_low_pages_nopanic( > PAGE_ALIGN(io_tlb_overflow)); > > and > /* > * When the IOMMU overflows we return a fallback buffer. This > sets the size. > */ > static unsigned long io_tlb_overflow = 32*1024; > > so it is 32K, and I round it to 8M. > So put that into prose, understandable by someone who hasn't followed this discussion (say, five years from now), and make that part of the commit. -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3] x86, kdump: Set crashkernel_low automatically
On Mon, Mar 18, 2013 at 3:52 PM, H. Peter Anvin wrote: > On 03/18/2013 02:25 PM, Yinghai Lu wrote: >> Current code does not set low range for crashkernel if the user >> does not specify that. >> >> That cause regressions on system that does not support intel_iommu >> properly. >> >> Chao said that his system does work well on 3.8 without extra parameter. >> even iommu does not work with kdump. >> >> Set crashkernel_low automatically if the user does not specify that. >> >> For system that does support IOMMU with kdump properly, user could >> specify crashkernel_low=0 to save that 72M low ram. >> >> -v3: add swiotlb_size() according to Konrad. >> >> Reported-by: WANG Chao >> Tested-by: WANG Chao >> Signed-off-by: Yinghai Lu > > Can we get a bit more of an explanation instead of "and etc 8M"? At > least a hint of what kind of objects would go in there... now only have: swiotlb overflow buffer v_overflow_buffer = alloc_bootmem_low_pages_nopanic( PAGE_ALIGN(io_tlb_overflow)); and /* * When the IOMMU overflows we return a fallback buffer. This sets the size. */ static unsigned long io_tlb_overflow = 32*1024; so it is 32K, and I round it to 8M. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3] x86, kdump: Set crashkernel_low automatically
On 03/18/2013 02:25 PM, Yinghai Lu wrote: > Current code does not set low range for crashkernel if the user > does not specify that. > > That cause regressions on system that does not support intel_iommu > properly. > > Chao said that his system does work well on 3.8 without extra parameter. > even iommu does not work with kdump. > > Set crashkernel_low automatically if the user does not specify that. > > For system that does support IOMMU with kdump properly, user could > specify crashkernel_low=0 to save that 72M low ram. > > -v3: add swiotlb_size() according to Konrad. > > Reported-by: WANG Chao > Tested-by: WANG Chao > Signed-off-by: Yinghai Lu Can we get a bit more of an explanation instead of "and etc 8M"? At least a hint of what kind of objects would go in there... -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
