From: kernel test robot <lkp@intel.com>
To: Wanpeng Li <kernellwp@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>
Cc: oe-kbuild-all@lists.linux.dev,
K Prateek Nayak <kprateek.nayak@amd.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Juri Lelli <juri.lelli@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Wanpeng Li <wanpengli@tencent.com>
Subject: Re: [PATCH v2 4/9] sched/fair: Add penalty calculation and application logic
Date: Tue, 23 Dec 2025 07:36:43 +0800 [thread overview]
Message-ID: <202512230746.EpT2QbVU-lkp@intel.com> (raw)
In-Reply-To: <20251219035334.39790-5-kernellwp@gmail.com>
Hi Wanpeng,
kernel test robot noticed the following build warnings:
[auto build test WARNING on kvm/queue]
[also build test WARNING on kvm/next tip/sched/core peterz-queue/sched/core tip/master linus/master v6.19-rc2 next-20251219]
[cannot apply to kvm/linux-next tip/auto-latest]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Wanpeng-Li/sched-fair-Add-rate-limiting-and-validation-helpers/20251219-125353
base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link: https://lore.kernel.org/r/20251219035334.39790-5-kernellwp%40gmail.com
patch subject: [PATCH v2 4/9] sched/fair: Add penalty calculation and application logic
config: openrisc-randconfig-r122-20251221 (https://download.01.org/0day-ci/archive/20251223/202512230746.EpT2QbVU-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251223/202512230746.EpT2QbVU-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512230746.EpT2QbVU-lkp@intel.com/
sparse warnings: (new ones prefixed by >>)
kernel/sched/fair.c:1158:49: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct task_struct *running @@ got struct task_struct [noderef] __rcu *curr @@
kernel/sched/fair.c:1158:49: sparse: expected struct task_struct *running
kernel/sched/fair.c:1158:49: sparse: got struct task_struct [noderef] __rcu *curr
kernel/sched/fair.c:1194:33: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct sched_entity *se @@ got struct sched_entity [noderef] __rcu * @@
kernel/sched/fair.c:1194:33: sparse: expected struct sched_entity *se
kernel/sched/fair.c:1194:33: sparse: got struct sched_entity [noderef] __rcu *
kernel/sched/fair.c:1250:34: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct sched_entity const *se @@ got struct sched_entity [noderef] __rcu * @@
kernel/sched/fair.c:1250:34: sparse: expected struct sched_entity const *se
kernel/sched/fair.c:1250:34: sparse: got struct sched_entity [noderef] __rcu *
kernel/sched/fair.c:13176:9: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sched_domain *[assigned] sd @@ got struct sched_domain [noderef] __rcu *parent @@
kernel/sched/fair.c:13176:9: sparse: expected struct sched_domain *[assigned] sd
kernel/sched/fair.c:13176:9: sparse: got struct sched_domain [noderef] __rcu *parent
kernel/sched/fair.c:8354:20: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sched_domain *[assigned] sd @@ got struct sched_domain [noderef] __rcu *parent @@
kernel/sched/fair.c:8354:20: sparse: expected struct sched_domain *[assigned] sd
kernel/sched/fair.c:8354:20: sparse: got struct sched_domain [noderef] __rcu *parent
kernel/sched/fair.c:8558:9: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sched_domain *[assigned] tmp @@ got struct sched_domain [noderef] __rcu *parent @@
kernel/sched/fair.c:8558:9: sparse: expected struct sched_domain *[assigned] tmp
kernel/sched/fair.c:8558:9: sparse: got struct sched_domain [noderef] __rcu *parent
kernel/sched/fair.c:8757:39: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct task_struct *donor @@ got struct task_struct [noderef] __rcu *donor @@
kernel/sched/fair.c:8757:39: sparse: expected struct task_struct *donor
kernel/sched/fair.c:8757:39: sparse: got struct task_struct [noderef] __rcu *donor
kernel/sched/fair.c:8784:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct task_struct *tsk @@ got struct task_struct [noderef] __rcu *curr @@
kernel/sched/fair.c:8784:37: sparse: expected struct task_struct *tsk
kernel/sched/fair.c:8784:37: sparse: got struct task_struct [noderef] __rcu *curr
kernel/sched/fair.c:9089:20: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct task_struct *p_yielding @@ got struct task_struct [noderef] __rcu *donor @@
kernel/sched/fair.c:9089:20: sparse: expected struct task_struct *p_yielding
kernel/sched/fair.c:9089:20: sparse: got struct task_struct [noderef] __rcu *donor
>> kernel/sched/fair.c:9150:44: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct task_struct *p_yielding @@ got struct task_struct [noderef] __rcu *donor @@
kernel/sched/fair.c:9150:44: sparse: expected struct task_struct *p_yielding
kernel/sched/fair.c:9150:44: sparse: got struct task_struct [noderef] __rcu *donor
kernel/sched/fair.c:9295:38: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct task_struct *curr @@ got struct task_struct [noderef] __rcu *donor @@
kernel/sched/fair.c:9295:38: sparse: expected struct task_struct *curr
kernel/sched/fair.c:9295:38: sparse: got struct task_struct [noderef] __rcu *donor
kernel/sched/fair.c:10331:40: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct sched_domain *child @@ got struct sched_domain [noderef] __rcu *child @@
kernel/sched/fair.c:10331:40: sparse: expected struct sched_domain *child
kernel/sched/fair.c:10331:40: sparse: got struct sched_domain [noderef] __rcu *child
kernel/sched/fair.c:10959:22: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/fair.c:10959:22: sparse: struct task_struct [noderef] __rcu *
kernel/sched/fair.c:10959:22: sparse: struct task_struct *
kernel/sched/fair.c:12431:9: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sched_domain *[assigned] sd @@ got struct sched_domain [noderef] __rcu *parent @@
kernel/sched/fair.c:12431:9: sparse: expected struct sched_domain *[assigned] sd
kernel/sched/fair.c:12431:9: sparse: got struct sched_domain [noderef] __rcu *parent
kernel/sched/fair.c:12069:44: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct sched_domain *sd_parent @@ got struct sched_domain [noderef] __rcu *parent @@
kernel/sched/fair.c:12069:44: sparse: expected struct sched_domain *sd_parent
kernel/sched/fair.c:12069:44: sparse: got struct sched_domain [noderef] __rcu *parent
kernel/sched/fair.c:12544:9: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sched_domain *[assigned] sd @@ got struct sched_domain [noderef] __rcu *parent @@
kernel/sched/fair.c:12544:9: sparse: expected struct sched_domain *[assigned] sd
kernel/sched/fair.c:12544:9: sparse: got struct sched_domain [noderef] __rcu *parent
kernel/sched/fair.c:6688:35: sparse: sparse: marked inline, but without a definition
kernel/sched/fair.c: note: in included file:
kernel/sched/sched.h:2647:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/sched.h:2647:9: sparse: struct task_struct [noderef] __rcu *
kernel/sched/sched.h:2647:9: sparse: struct task_struct *
kernel/sched/sched.h:2314:26: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/sched.h:2314:26: sparse: struct task_struct [noderef] __rcu *
kernel/sched/sched.h:2314:26: sparse: struct task_struct *
kernel/sched/sched.h:2303:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/sched.h:2303:25: sparse: struct task_struct [noderef] __rcu *
kernel/sched/sched.h:2303:25: sparse: struct task_struct *
kernel/sched/sched.h:2314:26: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/sched.h:2314:26: sparse: struct task_struct [noderef] __rcu *
kernel/sched/sched.h:2314:26: sparse: struct task_struct *
kernel/sched/sched.h:2314:26: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/sched.h:2314:26: sparse: struct task_struct [noderef] __rcu *
kernel/sched/sched.h:2314:26: sparse: struct task_struct *
kernel/sched/sched.h:2314:26: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/sched/sched.h:2314:26: sparse: struct task_struct [noderef] __rcu *
kernel/sched/sched.h:2314:26: sparse: struct task_struct *
vim +9150 kernel/sched/fair.c
9134
9135 /*
9136 * Apply debounce for reverse yield pairs to reduce ping-pong effects.
9137 * When A yields to B, then B yields back to A within ~600us, downscale
9138 * the penalty to prevent oscillation.
9139 *
9140 * The 600us threshold is chosen to be:
9141 * - Long enough to catch rapid back-and-forth yields
9142 * - Short enough to not affect legitimate sequential yields
9143 *
9144 * Returns the (possibly reduced) penalty value.
9145 */
9146 static u64 yield_deboost_apply_debounce(struct rq *rq, struct task_struct *p_target,
9147 u64 penalty, u64 need, u64 gran)
9148 {
9149 u64 now = rq_clock(rq);
> 9150 struct task_struct *p_yielding = rq->donor;
9151 pid_t src_pid, dst_pid;
9152 pid_t last_src, last_dst;
9153 u64 last_ns;
9154
9155 if (!p_yielding || !p_target)
9156 return penalty;
9157
9158 src_pid = p_yielding->pid;
9159 dst_pid = p_target->pid;
9160 last_src = rq->yield_deboost_last_src_pid;
9161 last_dst = rq->yield_deboost_last_dst_pid;
9162 last_ns = rq->yield_deboost_last_pair_time_ns;
9163
9164 /* Detect reverse pair: previous was target->source */
9165 if (last_src == dst_pid && last_dst == src_pid &&
9166 (now - last_ns) <= 600 * NSEC_PER_USEC) {
9167 u64 alt = max(need, gran);
9168
9169 if (penalty > alt)
9170 penalty = alt;
9171 }
9172
9173 /* Update tracking state */
9174 rq->yield_deboost_last_src_pid = src_pid;
9175 rq->yield_deboost_last_dst_pid = dst_pid;
9176 rq->yield_deboost_last_pair_time_ns = now;
9177
9178 return penalty;
9179 }
9180
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next prev parent reply other threads:[~2025-12-22 23:37 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-19 3:53 [PATCH v2 0/9] sched/kvm: Semantics-aware vCPU scheduling for oversubscribed KVM Wanpeng Li
2025-12-19 3:53 ` [PATCH v2 1/9] sched: Add vCPU debooster infrastructure Wanpeng Li
2025-12-19 3:53 ` [PATCH v2 2/9] sched/fair: Add rate-limiting and validation helpers Wanpeng Li
2025-12-22 21:12 ` kernel test robot
2026-01-04 4:09 ` Hillf Danton
2025-12-19 3:53 ` [PATCH v2 3/9] sched/fair: Add cgroup LCA finder for hierarchical yield Wanpeng Li
2025-12-19 3:53 ` [PATCH v2 4/9] sched/fair: Add penalty calculation and application logic Wanpeng Li
2025-12-22 23:36 ` kernel test robot [this message]
2025-12-19 3:53 ` [PATCH v2 5/9] sched/fair: Wire up yield deboost in yield_to_task_fair() Wanpeng Li
2025-12-22 7:06 ` kernel test robot
2025-12-22 9:31 ` kernel test robot
2025-12-19 3:53 ` [PATCH v2 6/9] KVM: x86: Add IPI tracking infrastructure Wanpeng Li
2025-12-19 3:53 ` [PATCH v2 7/9] KVM: x86/lapic: Integrate IPI tracking with interrupt delivery Wanpeng Li
2025-12-19 3:53 ` [PATCH v2 8/9] KVM: Implement IPI-aware directed yield candidate selection Wanpeng Li
2025-12-19 3:53 ` [PATCH v2 9/9] KVM: Relaxed boost as safety net Wanpeng Li
2026-01-04 2:40 ` [PATCH v2 0/9] sched/kvm: Semantics-aware vCPU scheduling for oversubscribed KVM Wanpeng Li
2026-01-05 6:26 ` K Prateek Nayak
2026-03-13 1:13 ` Sean Christopherson
2026-04-01 9:48 ` Wanpeng Li
2026-04-02 23:43 ` Sean Christopherson
2026-03-26 14:41 ` Christian Borntraeger
2026-04-01 9:34 ` Wanpeng Li
2026-04-08 9:35 ` Richie Buturla
2026-04-17 11:30 ` Richie Buturla
2026-05-13 12:52 ` Richie Buturla
2026-06-12 14:07 ` Wanpeng Li
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