From: Tejun Heo <tj@kernel.org> mainline inclusion from mainline-v6.12-rc1 commit 6f34d8d382d64e7d8e77f5a9ddfd06f4c04937b0 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ID7HLY Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- While bypassing, tasks are scheduled in FIFO order which favors tasks that hog CPUs. This can slow down e.g. unloading of the BPF scheduler. While bypassing, guaranteeing timely forward progress is the main goal. There's no point in giving long slices. Shorten the time slice used while bypassing from 20ms to 5ms. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David Vernet <void@manifault.com> Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Signed-off-by: cheliequan <cheliequan@inspur.com> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/sched/ext.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 8889549a55bf..790a6f6db130 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -13,6 +13,7 @@ #define SCX_OP_IDX(op) (offsetof(struct sched_ext_ops, op) / sizeof(void (*)(void))) enum scx_consts { + SCX_SLICE_BYPASS = SCX_SLICE_DFL / 4, SCX_DSP_DFL_MAX_BATCH = 32, SCX_DSP_MAX_LOOPS = 32, SCX_WATCHDOG_MAX_TIMEOUT = 30 * HZ, @@ -1953,6 +1954,7 @@ static bool scx_rq_online(struct rq *rq) static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags, int sticky_cpu) { + bool bypassing = scx_rq_bypassing(rq); struct task_struct **ddsp_taskp; unsigned long qseq; @@ -1970,7 +1972,7 @@ static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags, if (!scx_rq_online(rq)) goto local; - if (scx_rq_bypassing(rq)) + if (bypassing) goto global; if (p->scx.ddsp_dsq_id != SCX_DSQ_INVALID) @@ -2025,7 +2027,7 @@ static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags, global: touch_core_sched(rq, p); /* see the comment in local: */ - p->scx.slice = SCX_SLICE_DFL; + p->scx.slice = bypassing ? SCX_SLICE_BYPASS : SCX_SLICE_DFL; dispatch_enqueue(find_global_dsq(p), p, enq_flags); } -- 2.34.1