From: Dexuan Cui decui@microsoft.com

A cpumask structure on the stack can cause a warning with CONFIG_NR_CPUS=8192 (e.g. Ubuntu 16.04 and 18.04 use this):

drivers/hv//channel_mgmt.c: In function ‘init_vp_index’: drivers/hv//channel_mgmt.c:702:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Nowadays it looks most distros enable CONFIG_CPUMASK_OFFSTACK=y, and hence we can work around the warning by using cpumask_var_t.

Signed-off-by: Dexuan Cui decui@microsoft.com Cc: K. Y. Srinivasan kys@microsoft.com Cc: Haiyang Zhang haiyangz@microsoft.com Cc: Stephen Hemminger sthemmin@microsoft.com Cc: Stable@vger.kernel.org Signed-off-by: K. Y. Srinivasan kys@microsoft.com --- drivers/hv/channel_mgmt.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index e7598b569bea..d943fa022e34 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -601,16 +601,18 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) bool perf_chn = vmbus_devs[dev_type].perf_device; struct vmbus_channel *primary = channel->primary_channel; int next_node; - struct cpumask available_mask; + cpumask_var_t available_mask; struct cpumask *alloced_mask;

if ((vmbus_proto_version == VERSION_WS2008) || - (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { + (vmbus_proto_version == VERSION_WIN7) || (!perf_chn) || + !alloc_cpumask_var(&available_mask, GFP_KERNEL)) { /* * Prior to win8, all channel interrupts are * delivered on cpu 0. * Also if the channel is not a performance critical * channel, bind it to cpu 0. + * In case alloc_cpumask_var() fails, bind it to cpu 0. */ channel->numa_node = 0; channel->target_cpu = 0; @@ -648,7 +650,7 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) cpumask_clear(alloced_mask); }

- cpumask_xor(&available_mask, alloced_mask, + cpumask_xor(available_mask, alloced_mask, cpumask_of_node(primary->numa_node));

cur_cpu = -1; @@ -666,10 +668,10 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) }

while (true) { - cur_cpu = cpumask_next(cur_cpu, &available_mask); + cur_cpu = cpumask_next(cur_cpu, available_mask); if (cur_cpu >= nr_cpu_ids) { cur_cpu = -1; - cpumask_copy(&available_mask, + cpumask_copy(available_mask, cpumask_of_node(primary->numa_node)); continue; } @@ -699,6 +701,8 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type)

channel->target_cpu = cur_cpu; channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu); + + free_cpumask_var(available_mask); }

static void vmbus_wait_for_unload(void)