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Drivers: hv: vmbus: Don't assign VMbus channel interrupts to isolated CPUs

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When initially assigning a VMbus channel interrupt to a CPU, don’t choose
a managed IRQ isolated CPU (as specified on the kernel boot line with
parameter 'isolcpus=managed_irq,<#cpu>'). Also, when using sysfs to change
the CPU that a VMbus channel will interrupt, don't allow changing to a
managed IRQ isolated CPU.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1653637439-23060-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Saurabh Sengar 2022-05-27 00:43:59 -07:00 committed by Wei Liu
parent f2906aa863
commit 6640b5df1a
2 changed files with 16 additions and 5 deletions
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17
drivers/hv/channel_mgmt.c
View file

@ -21,6 +21,7 @@
#include <linux/cpu.h>
#include <linux/hyperv.h>
#include <asm/mshyperv.h>
#include <linux/sched/isolation.h>
#include "hyperv_vmbus.h"
@ -728,16 +729,20 @@ static void init_vp_index(struct vmbus_channel *channel)
u32 i, ncpu = num_online_cpus();
cpumask_var_t available_mask;
struct cpumask *allocated_mask;
const struct cpumask *hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
u32 target_cpu;
int numa_node;
if (!perf_chn ||
!alloc_cpumask_var(&available_mask, GFP_KERNEL)) {
!alloc_cpumask_var(&available_mask, GFP_KERNEL) ||
cpumask_empty(hk_mask)) {
/*
* If the channel is not a performance critical
* channel, bind it to VMBUS_CONNECT_CPU.
* In case alloc_cpumask_var() fails, bind it to
* VMBUS_CONNECT_CPU.
* If all the cpus are isolated, bind it to
* VMBUS_CONNECT_CPU.
*/
channel->target_cpu = VMBUS_CONNECT_CPU;
if (perf_chn)
@ -758,17 +763,19 @@ static void init_vp_index(struct vmbus_channel *channel)
}
allocated_mask = &hv_context.hv_numa_map[numa_node];
if (cpumask_equal(allocated_mask, cpumask_of_node(numa_node))) {
retry:
cpumask_xor(available_mask, allocated_mask, cpumask_of_node(numa_node));
cpumask_and(available_mask, available_mask, hk_mask);
if (cpumask_empty(available_mask)) {
/*
* We have cycled through all the CPUs in the node;
* reset the allocated map.
*/
cpumask_clear(allocated_mask);
goto retry;
}
cpumask_xor(available_mask, allocated_mask,
cpumask_of_node(numa_node));
target_cpu = cpumask_first(available_mask);
cpumask_set_cpu(target_cpu, allocated_mask);

4
drivers/hv/vmbus_drv.c
View file

@ -21,6 +21,7 @@
#include <linux/kernel_stat.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/sched/isolation.h>
#include <linux/sched/task_stack.h>
#include <linux/delay.h>
@ -1770,6 +1771,9 @@ static ssize_t target_cpu_store(struct vmbus_channel *channel,
if (target_cpu >= nr_cpumask_bits)
return -EINVAL;
if (!cpumask_test_cpu(target_cpu, housekeeping_cpumask(HK_TYPE_MANAGED_IRQ)))
return -EINVAL;
/* No CPUs should come up or down during this. */
cpus_read_lock();