alloc_net_device() allocates the fixed-channel netvsc_device with kzalloc_obj(). The runtime fragmentation drill reaches this allocation from netvsc_device_add(): windows-2025 reports an order-7 allocation failure with about 99 MiB free, while windows-latest stalls at channel open until the guest timeout.
This object is guest-private control-plane metadata, not DMA backing. Use kvzalloc_obj() so the allocation can fall back to vmalloc when a high-order kmalloc cannot be satisfied. Zero initialization is preserved. The RCU workqueue cleanup uses kvfree() to release either backing. Rollback trigger: revert if channel setup fails with vmalloc capacity available or teardown leaves netvsc_device allocations outstanding. Signed-off-by: Emerson Busson <[email protected]> --- drivers/net/hyperv/netvsc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 0d017f836b9e..8ea7c993baac 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -144,7 +144,7 @@ static void __free_netvsc_device(struct netvsc_device *nvdev) vfree(nvdev->chan_table[i].mrc.slots); } - kfree(nvdev); + kvfree(nvdev); } static void free_netvsc_device(struct work_struct *w) @@ -171,7 +171,7 @@ static struct netvsc_device *alloc_net_device(void) { struct netvsc_device *net_device; - net_device = kzalloc_obj(struct netvsc_device); + net_device = kvzalloc_obj(struct netvsc_device); if (!net_device) return NULL; -- 2.43.0
