On 14/04/2020 17:51, Vitaly Kuznetsov wrote:
> Colin King <colin.king@xxxxxxxxxxxxx> writes:
>
>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>
>> The pointer primary_channel is being assigned with a value that is never,
>> The assignment is redundant and can be removed.
>>
>> Addresses-Coverity: ("Unused value")
>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>> ---
>> drivers/hv/channel_mgmt.c | 2 --
>> 1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
>> index ffd7fffa5f83..f7bbb8dc4b0f 100644
>> --- a/drivers/hv/channel_mgmt.c
>> +++ b/drivers/hv/channel_mgmt.c
>> @@ -425,8 +425,6 @@ void hv_process_channel_removal(struct vmbus_channel *channel)
>>
>> if (channel->primary_channel == NULL) {
>> list_del(&channel->listentry);
>> -
>> - primary_channel = channel;
>> } else {
>> primary_channel = channel->primary_channel;
>> spin_lock_irqsave(&primary_channel->lock, flags);
>
> If I'm looking at the right source (5.7-rc1) it *is* beeing used:
>
> if (channel->primary_channel == NULL) {
> list_del(&channel->listentry);
>
> primary_channel = channel;
> } else {
> primary_channel = channel->primary_channel;
> spin_lock_irqsave(&primary_channel->lock, flags);
> list_del(&channel->sc_list);
> spin_unlock_irqrestore(&primary_channel->lock, flags);
> }
>
> /*
> * We need to free the bit for init_vp_index() to work in the case
> * of sub-channel, when we reload drivers like hv_netvsc.
> */
> if (channel->affinity_policy == HV_LOCALIZED)
> cpumask_clear_cpu(channel->target_cpu,
> &primary_channel->alloced_cpus_in_node);
> ^^^^^ HERE ^^^^^
>
I was basing my change on linux-next that has removed a hunk of code:
commit bcefa400900739310e8ef0cb34cbe029c404455c
Author: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
Date: Mon Apr 6 02:15:11 2020 +0200
Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity
logic
The logic is unused since commit 509879bdb30b8 ("Drivers: hv: Introduce
a policy for controlling channel affinity").
This logic assumes that a channel target_cpu doesn't change during the
lifetime of a channel, but this assumption is incompatible with the new
functionality that allows changing the vCPU a channel will interrupt.
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
Link:
https://lore.kernel.org/r/20200406001514.19876-9-parri.andrea@xxxxxxxxx
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 7fb6eb647f14..476592b0bc00 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -433,14 +433,6 @@ void hv_process_channel_removal(struct
vmbus_channel *channel)
spin_unlock_irqrestore(&primary_channel->lock, flags);
}
- /*
- * We need to free the bit for init_vp_index() to work in the case
- * of sub-channel, when we reload drivers like hv_netvsc.
- */
- if (channel->affinity_policy == HV_LOCALIZED)
- cpumask_clear_cpu(channel->target_cpu,
- &primary_channel->alloced_cpus_in_node);
-
