I enabled CMA_DEBUG & CMA_DEBUGFS and booted w/ cma=128M so that we can see the CMA state when no allocations fail.
root@d06-4:/sys/kernel/debug/cma/cma-reserved# cat count 32768 root@d06-4:/sys/kernel/debug/cma/cma-reserved# cat used 15630 Looks like we're actually using ~61M - and perhaps the alignment requirements are pushing us over the 64M barrier (cma=64M still results in some cma_alloc failures). ** Attachment added: "dmesg w/ CMA_DEBUG=y" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1823753/+attachment/5254279/+files/dmesg-cma-debug.txt -- 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: Incomplete 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
