Commit e73a8f38 authored by Alexey Makhalov's avatar Alexey Makhalov Committed by Borislav Petkov
Browse files

x86/vmware: Enable steal time accounting 



Set paravirt_steal_rq_enabled if steal clock present.
paravirt_steal_rq_enabled is used in sched/core.c to adjust task
progress by offsetting stolen time. Use 'no-steal-acc' off switch (share
same name with KVM) to disable steal time accounting.

Signed-off-by: default avatarAlexey Makhalov <amakhalov@vmware.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200323195707.31242-5-amakhalov@vmware.com
parent ab02bb3f

Documentation/admin-guide/kernel-parameters.txt

+1 −1
Original line number Diff line number Diff line
@@ -3174,7 +3174,7 @@ 
			[X86,PV_OPS] Disable paravirtualized VMware scheduler

			clock and use the default one.



	no-steal-acc	[X86,KVM,ARM64] Disable paravirtualized steal time

	no-steal-acc	[X86,PV_OPS,ARM64] Disable paravirtualized steal time

			accounting. steal time is computed, but won't

			influence scheduler behaviour

arch/x86/kernel/cpu/vmware.c

+12 −1
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ static struct cyc2ns_data vmware_cyc2ns __ro_after_init; 
static int vmw_sched_clock __initdata = 1;

static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);

static bool has_steal_clock;

static bool steal_acc __initdata = true; /* steal time accounting */



static __init int setup_vmw_sched_clock(char *s)

{
@@ -133,6 +134,13 @@ static __init int setup_vmw_sched_clock(char *s) 
}

early_param("no-vmw-sched-clock", setup_vmw_sched_clock);



static __init int parse_no_stealacc(char *arg)

{

	steal_acc = false;

	return 0;

}

early_param("no-steal-acc", parse_no_stealacc);



static unsigned long long notrace vmware_sched_clock(void)

{

	unsigned long long ns;
@@ -306,8 +314,11 @@ static int vmware_cpu_down_prepare(unsigned int cpu) 


static __init int activate_jump_labels(void)

{

	if (has_steal_clock)

	if (has_steal_clock) {

		static_key_slow_inc(&paravirt_steal_enabled);

		if (steal_acc)

			static_key_slow_inc(&paravirt_steal_rq_enabled);

	}



	return 0;

}

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