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| author | Saurabh Sengar <ssengar@linux.microsoft.com> | 2024-08-01 06:55:36 +0200 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2024-08-24 00:06:51 +0200 |
| commit | 87c9741a38c4fa63ff3525c3191fb8a4a69b4ff6 (patch) | |
| tree | c5af76c62e4884ddb0f570c32b552af474060a79 /drivers/hv/vmbus_drv.c | |
| parent | Linux 6.11-rc4 (diff) | |
| download | linux-87c9741a38c4fa63ff3525c3191fb8a4a69b4ff6.tar.xz linux-87c9741a38c4fa63ff3525c3191fb8a4a69b4ff6.zip | |
Drivers: hv: vmbus: Optimize boot time by concurrent execution of hv_synic_init()
Currently on a very large system with 1780 CPUs, hv_acpi_init() takes
around 3 seconds to complete. This is because of sequential synic
initialization for each CPU performed by hv_synic_init().
Schedule these tasks parallelly so that each CPU executes hv_synic_init()
in parallel to take full advantage of multiple CPUs.
This solution saves around 2 seconds of boot time on a 1780 CPU system,
which is around 66% improvement in the existing logic.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Srivatsa S. Bhat (Microsoft) <srivatsa@csail.mit.edu>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1722488136-6223-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1722488136-6223-1-git-send-email-ssengar@linux.microsoft.com>
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index c857dc3975be..7242c4920427 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1306,6 +1306,13 @@ static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id) return IRQ_HANDLED; } +static void vmbus_percpu_work(struct work_struct *work) +{ + unsigned int cpu = smp_processor_id(); + + hv_synic_init(cpu); +} + /* * vmbus_bus_init -Main vmbus driver initialization routine. * @@ -1316,7 +1323,8 @@ static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id) */ static int vmbus_bus_init(void) { - int ret; + int ret, cpu; + struct work_struct __percpu *works; ret = hv_init(); if (ret != 0) { @@ -1355,12 +1363,32 @@ static int vmbus_bus_init(void) if (ret) goto err_alloc; + works = alloc_percpu(struct work_struct); + if (!works) { + ret = -ENOMEM; + goto err_alloc; + } + /* * Initialize the per-cpu interrupt state and stimer state. * Then connect to the host. */ - ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online", - hv_synic_init, hv_synic_cleanup); + cpus_read_lock(); + for_each_online_cpu(cpu) { + struct work_struct *work = per_cpu_ptr(works, cpu); + + INIT_WORK(work, vmbus_percpu_work); + schedule_work_on(cpu, work); + } + + for_each_online_cpu(cpu) + flush_work(per_cpu_ptr(works, cpu)); + + /* Register the callbacks for possible CPU online/offline'ing */ + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online", + hv_synic_init, hv_synic_cleanup); + cpus_read_unlock(); + free_percpu(works); if (ret < 0) goto err_alloc; hyperv_cpuhp_online = ret; |