On Thu, 18 Jun 2020 09:52:56 +0800 Lu Baolu <baolu...@linux.intel.com> wrote:
> Hi Alex, > > Thanks for the report. > > On 6/18/20 4:06 AM, Alex Williamson wrote: > > On Sat, 16 May 2020 14:21:01 +0800 > > Lu Baolu<baolu...@linux.intel.com> wrote: > > > >> From: Tom Murphy<murph...@tcd.ie> > >> > >> There's no need for the non-dma_ops path to keep track of IOVAs. The > >> whole point of the non-dma_ops path is that it allows the IOVAs to be > >> handled separately. The IOVA handling code removed in this patch is > >> pointless. > >> > >> Signed-off-by: Tom Murphy<murph...@tcd.ie> > >> Signed-off-by: Lu Baolu<baolu...@linux.intel.com> > >> --- > >> drivers/iommu/intel-iommu.c | 95 +++++++++++++------------------------ > >> 1 file changed, 32 insertions(+), 63 deletions(-) > > This commit results in a massive increase in memory use from the VT-d > > code. I have a 16GB system where I reserve 7168 2MB hugespages for VM > > usage (14GB), leaving the host with 2GB. I can no longer even boot the > > host in this configuration. Bisecting to this commit, I find that > > reverting this change shows the following memory usage difference > > immediately after boot (no hugepages, nosmp, single user, > > intel_iommu=on iommu=pt): > > > > @e70b081c6f37: > > total used free shared buff/cache > > available > > Mem: 16090860 2219372 13673044 1040 198444 > > 13602664 > > Swap: 2097148 0 2097148 > > > > reverting e70b081c6f37: > > total used free shared buff/cache > > available > > Mem: 16090852 101648 15789156 1040 200048 > > 15719572 > > Swap: 2097148 0 2097148 > > > > More than 2GB of additional memory used! There's also a notable stall > > during bootup for this allocation: > > > > [ 9.703360] DMAR: No ATSR found > > [ 9.709768] DMAR: dmar0: Using Queued invalidation > > [ 9.719370] DMAR: dmar1: Using Queued invalidation > > > > ### 4+ seconds! ### > > > > [ 14.076387] pci 0000:00:00.0: Adding to iommu group 0 > > [ 14.086515] pci 0000:00:01.0: Adding to iommu group 1 > > [ 14.096635] pci 0000:00:02.0: Adding to iommu group 2 > > Can you please try below changes? > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index 887f184b900d..7eb29167e8f9 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -2705,7 +2705,9 @@ static int __init si_domain_init(int hw) > end >> agaw_to_width(si_domain->agaw))) > continue; > > - ret = iommu_domain_identity_map(si_domain, > start, end); > + ret = iommu_domain_identity_map(si_domain, > + mm_to_dma_pfn(start >> PAGE_SHIFT), > + mm_to_dma_pfn(end >> PAGE_SHIFT)); > if (ret) > return ret; > } Yes, this resolves it. Used memory after boot returns to similar numbers as without this commit. Thanks, Alex _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
