diff options
| author | Tejun Heo <tj@kernel.org> | 2024-09-27 00:56:46 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2024-09-27 00:56:46 +0200 |
| commit | c9c809f4137c3c0f962226c10d245d3ce2fd5b7c (patch) | |
| tree | 32ab9b3beb467721b7f41f14620bdc932caf163e /tools/sched_ext | |
| parent | tools/sched_ext: Receive misc updates from SCX repo (diff) | |
| download | linux-c9c809f4137c3c0f962226c10d245d3ce2fd5b7c.tar.xz linux-c9c809f4137c3c0f962226c10d245d3ce2fd5b7c.zip | |
scx_flatcg: Use a user DSQ for fallback instead of SCX_DSQ_GLOBAL
scx_flatcg was using SCX_DSQ_GLOBAL for fallback handling. However, it is
assuming that SCX_DSQ_GLOBAL isn't automatically consumed, which was true a
while ago but is no longer the case. Also, there are further changes planned
for SCX_DSQ_GLOBAL which will disallow explicit consumption from it. Switch
to a user DSQ for fallback.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Diffstat (limited to 'tools/sched_ext')
| -rw-r--r-- | tools/sched_ext/scx_flatcg.bpf.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/tools/sched_ext/scx_flatcg.bpf.c b/tools/sched_ext/scx_flatcg.bpf.c index e272bc39bbbd..b722baf6da4b 100644 --- a/tools/sched_ext/scx_flatcg.bpf.c +++ b/tools/sched_ext/scx_flatcg.bpf.c @@ -49,7 +49,10 @@ /* * Maximum amount of retries to find a valid cgroup. */ -#define CGROUP_MAX_RETRIES 1024 +enum { + FALLBACK_DSQ = 0, + CGROUP_MAX_RETRIES = 1024, +}; char _license[] SEC("license") = "GPL"; @@ -377,7 +380,7 @@ void BPF_STRUCT_OPS(fcg_enqueue, struct task_struct *p, u64 enq_flags) scx_bpf_dispatch(p, SCX_DSQ_LOCAL, SCX_SLICE_DFL, enq_flags); } else { stat_inc(FCG_STAT_GLOBAL); - scx_bpf_dispatch(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags); + scx_bpf_dispatch(p, FALLBACK_DSQ, SCX_SLICE_DFL, enq_flags); } return; } @@ -780,7 +783,7 @@ void BPF_STRUCT_OPS(fcg_dispatch, s32 cpu, struct task_struct *prev) pick_next_cgroup: cpuc->cur_at = now; - if (scx_bpf_consume(SCX_DSQ_GLOBAL)) { + if (scx_bpf_consume(FALLBACK_DSQ)) { cpuc->cur_cgid = 0; return; } @@ -837,7 +840,7 @@ int BPF_STRUCT_OPS_SLEEPABLE(fcg_cgroup_init, struct cgroup *cgrp, int ret; /* - * Technically incorrect as cgroup ID is full 64bit while dq ID is + * Technically incorrect as cgroup ID is full 64bit while dsq ID is * 63bit. Should not be a problem in practice and easy to spot in the * unlikely case that it breaks. */ @@ -925,6 +928,11 @@ void BPF_STRUCT_OPS(fcg_cgroup_move, struct task_struct *p, p->scx.dsq_vtime = to_cgc->tvtime_now + vtime_delta; } +s32 BPF_STRUCT_OPS_SLEEPABLE(fcg_init) +{ + return scx_bpf_create_dsq(FALLBACK_DSQ, -1); +} + void BPF_STRUCT_OPS(fcg_exit, struct scx_exit_info *ei) { UEI_RECORD(uei, ei); @@ -943,6 +951,7 @@ SCX_OPS_DEFINE(flatcg_ops, .cgroup_init = (void *)fcg_cgroup_init, .cgroup_exit = (void *)fcg_cgroup_exit, .cgroup_move = (void *)fcg_cgroup_move, + .init = (void *)fcg_init, .exit = (void *)fcg_exit, .flags = SCX_OPS_HAS_CGROUP_WEIGHT | SCX_OPS_ENQ_EXITING, .name = "flatcg"); |