I only had time to look briefly, but here's a few notes. Firstly, a workaround for now is passing cma=0 on the kernel command line.
I feel like there must be something wrong here if everything just works fine with CMA turned off, because obviously devices are getting CMA allocations when they don't really need them. I'm not familiar with CMA, but my assumption would be that you want as small a region as possible for it and thus you want to only use it for devices where it's actually necessary. Shooting from the hip I'd guess that one of two things is wrong, either some devices are doing their allocations wrong and getting CMA memory when they don't need it, or the DMA allocator is over zealous in its use of CMA. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1823753 Title: arm64: cma_alloc errors at boot Status in linux package in Ubuntu: Confirmed Bug description: On some arm64 systems[*] we are seeing a spew of messages on the console: [ 19.534097] cma: cma_alloc: alloc failed, req-size: 64 pages, ret: -12 [ 19.534109] cma: cma_alloc: alloc failed, req-size: 16 pages, ret: -12 [ 19.534113] cma: cma_alloc: alloc failed, req-size: 64 pages, ret: -12 [ 19.534126] cma: cma_alloc: alloc failed, req-size: 16 pages, ret: -12 [ 19.534130] cma: cma_alloc: alloc failed, req-size: 64 pages, ret: -12 [ 19.534142] cma: cma_alloc: alloc failed, req-size: 16 pages, ret: -12 [ 19.534146] cma: cma_alloc: alloc failed, req-size: 64 pages, ret: -12 [ 19.534157] cma: cma_alloc: alloc failed, req-size: 16 pages, ret: -12 [ 19.534161] cma: cma_alloc: alloc failed, req-size: 64 pages, ret: -12 [ 19.534173] cma: cma_alloc: alloc failed, req-size: 16 pages, ret: -12 [ 19.534177] cma: cma_alloc: alloc failed, req-size: 64 pages, ret: -12 This appears to be non-fatal - impacted systems all eventually boot. But, at least in the case of the HP m400, it slows down boot enough that MAAS' default timeout will expire before completing deployment. [*] Observed on a HiSilicon D06 w/ SMMU disabled in the BIOS, as well as an HP m400 (APM X-Gene) cartridge - although, not on another one that - in theory - should be identical. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1823753/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
