Commit f01c6f2d authored by Jim Harris's avatar Jim Harris Committed by Konrad Sztyber
Browse files

scheduler: save scheduler period in microseconds (in addition to tsc) 



We need to use TSC internally to determine when to do the scheduling,
but the user interface is in microseconds. To avoid rounding errors
when converting from microseconds => TSC => microseconds, save the
user specified value in microseconds instead.

Fixes issue #3546.

Signed-off-by: default avatarJim Harris <jim.harris@samsung.com>
Change-Id: I01143b047c5db58163b013fb58ca0364634e6365
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/25223


Reviewed-by: default avatarGangCao <gang.cao@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeliu@tencent.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarMichal Berger <michal.berger@intel.com>
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Community CI Samsung <spdk.community.ci.samsung@gmail.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
parent fa3ab738

lib/event/reactor.c

+7 −7
Original line number Diff line number Diff line
@@ -47,7 +47,8 @@ TAILQ_HEAD(, spdk_scheduler) g_scheduler_list 
static struct spdk_scheduler *g_scheduler = NULL;

static struct spdk_reactor *g_scheduling_reactor;

bool g_scheduling_in_progress = false;

static uint64_t g_scheduler_period = 0;

static uint64_t g_scheduler_period_in_tsc = 0;

static uint64_t g_scheduler_period_in_us;

static uint32_t g_scheduler_core_number;

static struct spdk_scheduler_core_info *g_core_infos = NULL;

static struct spdk_cpuset g_scheduler_isolated_core_mask;
@@ -134,15 +135,14 @@ spdk_scheduler_get(void) 
uint64_t

spdk_scheduler_get_period(void)

{

	/* Convert from ticks to microseconds */

	return (g_scheduler_period * SPDK_SEC_TO_USEC / spdk_get_ticks_hz());

	return g_scheduler_period_in_us;

}



void

spdk_scheduler_set_period(uint64_t period)

{

	/* Convert microseconds to ticks */

	g_scheduler_period = period * spdk_get_ticks_hz() / SPDK_SEC_TO_USEC;

	g_scheduler_period_in_us = period;

	g_scheduler_period_in_tsc = period * spdk_get_ticks_hz() / SPDK_SEC_TO_USEC;

}



void
@@ -1029,8 +1029,8 @@ reactor_run(void *arg) 
			}

		}



		if (spdk_unlikely(g_scheduler_period > 0 &&

				  (reactor->tsc_last - last_sched) > g_scheduler_period &&

		if (spdk_unlikely(g_scheduler_period_in_tsc > 0 &&

				  (reactor->tsc_last - last_sched) > g_scheduler_period_in_tsc &&

				  reactor == g_scheduling_reactor &&

				  !g_scheduling_in_progress)) {

			last_sched = reactor->tsc_last;