From: Jakub Kicinski <k...@kernel.org> Date: Sun, 28 Feb 2021 10:55:52 -0800
> On Sun, 28 Feb 2021 18:14:46 +0000 Alexander Lobakin wrote: > > > [1] WARNING in __alloc_pages_nodemask+0x5f8/0x730 mm/page_alloc.c:5014 > > > Call Trace: > > > __alloc_pages include/linux/gfp.h:511 [inline] > > > __alloc_pages_node include/linux/gfp.h:524 [inline] > > > alloc_pages_node include/linux/gfp.h:538 [inline] > > > kmalloc_large_node+0x60/0x110 mm/slub.c:3999 > > > __kmalloc_node_track_caller+0x319/0x3f0 mm/slub.c:4496 > > > __kmalloc_reserve net/core/skbuff.c:150 [inline] > > > __alloc_skb+0x4e4/0x5a0 net/core/skbuff.c:210 > > > __netdev_alloc_skb+0x70/0x400 net/core/skbuff.c:446 > > > netdev_alloc_skb include/linux/skbuff.h:2832 [inline] > > > qrtr_endpoint_post+0x84/0x11b0 net/qrtr/qrtr.c:442 > > > qrtr_tun_write_iter+0x11f/0x1a0 net/qrtr/tun.c:98 > > > call_write_iter include/linux/fs.h:1901 [inline] > > > new_sync_write+0x426/0x650 fs/read_write.c:518 > > > vfs_write+0x791/0xa30 fs/read_write.c:605 > > > ksys_write+0x12d/0x250 fs/read_write.c:658 > > > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Ah, by the way. Have you tried to seek for the root cause, why > > a request for such insanely large (at least 4 Mib) skb happens > > in QRTR? I don't believe it's intended to be like this. > > Now I feel that silencing this error with early return isn't > > really correct approach for this. > > Right, IIUC Eric suggested we limit the length of the allocation > to 64KB because that's the max reasonable skb length, and QRTR tun write > results in generating a single skb. That seems like a good approach. +1 for explicit capping max skb length to 64K. Al
