diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2015-05-07 03:47:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-05-24 22:19:00 +0300 |
| commit | ce59fec836a9b4dc51cbcf9cb245b59e0ef53bea (patch) | |
| tree | 2927aa4419cc9de7cc50b8f298b75e6dfbf7c40a /drivers/hv/channel_mgmt.c | |
| parent | f38e7dd72337d83cced910cfbf6016475ef85bf7 (diff) | |
| download | linux-ce59fec836a9b4dc51cbcf9cb245b59e0ef53bea.tar.xz | |
Drivers: hv: vmbus: distribute subchannels among all vcpus
Primary channels are distributed evenly across all vcpus we have. When the host
asks us to create subchannels it usually makes us num_cpus-1 offers and we are
supposed to distribute the work evenly among the channel itself and all its
subchannels. Make sure they are all assigned to different vcpus.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/channel_mgmt.c')
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 655c0a09c902..1f1417d19c7e 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -387,6 +387,8 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui int i; bool perf_chn = false; u32 max_cpus = num_online_cpus(); + struct vmbus_channel *primary = channel->primary_channel, *prev; + unsigned long flags; for (i = IDE; i < MAX_PERF_CHN; i++) { if (!memcmp(type_guid->b, hp_devs[i].guid, @@ -407,7 +409,32 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui channel->target_vp = 0; return; } - cur_cpu = (++next_vp % max_cpus); + + /* + * Primary channels are distributed evenly across all vcpus we have. + * When the host asks us to create subchannels it usually makes us + * num_cpus-1 offers and we are supposed to distribute the work evenly + * among the channel itself and all its subchannels. Make sure they are + * all assigned to different vcpus. + */ + if (!primary) + cur_cpu = (++next_vp % max_cpus); + else { + /* + * Let's assign the first subchannel of a channel to the + * primary->target_cpu+1 and all the subsequent channels to + * the prev->target_cpu+1. + */ + spin_lock_irqsave(&primary->lock, flags); + if (primary->num_sc == 1) + cur_cpu = (primary->target_cpu + 1) % max_cpus; + else { + prev = list_prev_entry(channel, sc_list); + cur_cpu = (prev->target_cpu + 1) % max_cpus; + } + spin_unlock_irqrestore(&primary->lock, flags); + } + channel->target_cpu = cur_cpu; channel->target_vp = hv_context.vp_index[cur_cpu]; } |