11:58 p.m.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core
head: 816969e4af7a56bfd284d2e0fa11511900ab93e3
commit: 6bcd3e21ba278098920d26d4888f5e6f4087c61d [2/5] sched/fair: Bring back
select_idle_smt(), but differently
config: ia64-randconfig-r034-20210409 (attached as .config)
compiler: ia64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
#
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=6b...
git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
git fetch --no-tags tip sched/core
git checkout 6bcd3e21ba278098920d26d4888f5e6f4087c61d
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
All errors (new ones prefixed by >>):
In file included from arch/ia64/include/asm/pgtable.h:154,
from include/linux/pgtable.h:6,
from arch/ia64/include/asm/uaccess.h:40,
from include/linux/uaccess.h:11,
from include/linux/sched/task.h:11,
from include/linux/sched/signal.h:9,
from include/linux/sched/cputime.h:5,
from kernel/sched/sched.h:11,
from kernel/sched/fair.c:23:
arch/ia64/include/asm/mmu_context.h: In function 'reload_context':
arch/ia64/include/asm/mmu_context.h:127:41: warning: variable 'old_rr4' set but
not used [-Wunused-but-set-variable]
127 | unsigned long rr0, rr1, rr2, rr3, rr4, old_rr4;
| ^~~~~~~
kernel/sched/fair.c: At top level:
kernel/sched/fair.c:5393:6: warning: no previous prototype for
'init_cfs_bandwidth' [-Wmissing-prototypes]
5393 | void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
| ^~~~~~~~~~~~~~~~~~
In file included from arch/ia64/include/uapi/asm/gcc_intrin.h:11,
from arch/ia64/include/asm/gcc_intrin.h:10,
from arch/ia64/include/uapi/asm/intrinsics.h:20,
from arch/ia64/include/asm/intrinsics.h:11,
from arch/ia64/include/asm/current.h:10,
from include/linux/sched.h:12,
from kernel/sched/sched.h:5,
from kernel/sched/fair.c:23:
kernel/sched/fair.c: In function 'select_idle_sibling':
> kernel/sched/fair.c:6345:28: error: 'sched_smt_present'
undeclared (first use in this function)
6345 | if
(static_branch_likely(&sched_smt_present)) {
| ^~~~~~~~~~~~~~~~~
include/linux/compiler.h:77:40: note: in definition of macro 'likely'
77 | # define likely(x) __builtin_expect(!!(x), 1)
| ^
include/linux/jump_label.h:480:34: note: in expansion of macro
'likely_notrace'
480 | #define static_branch_likely(x)
likely_notrace(static_key_enabled(&(x)->key))
| ^~~~~~~~~~~~~~
include/linux/jump_label.h:480:49: note: in expansion of macro
'static_key_enabled'
480 | #define static_branch_likely(x)
likely_notrace(static_key_enabled(&(x)->key))
| ^~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:6345:6: note: in expansion of macro 'static_branch_likely'
6345 | if (static_branch_likely(&sched_smt_present)) {
| ^~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:6345:28: note: each undeclared identifier is reported only once for
each function it appears in
6345 | if (static_branch_likely(&sched_smt_present)) {
| ^~~~~~~~~~~~~~~~~
include/linux/compiler.h:77:40: note: in definition of macro 'likely'
77 | # define likely(x) __builtin_expect(!!(x), 1)
| ^
include/linux/jump_label.h:480:34: note: in expansion of macro
'likely_notrace'
480 | #define static_branch_likely(x)
likely_notrace(static_key_enabled(&(x)->key))
| ^~~~~~~~~~~~~~
include/linux/jump_label.h:480:49: note: in expansion of macro
'static_key_enabled'
480 | #define static_branch_likely(x)
likely_notrace(static_key_enabled(&(x)->key))
| ^~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:6345:6: note: in expansion of macro 'static_branch_likely'
6345 | if (static_branch_likely(&sched_smt_present)) {
| ^~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c: At top level:
kernel/sched/fair.c:11232:6: warning: no previous prototype for
'free_fair_sched_group' [-Wmissing-prototypes]
11232 | void free_fair_sched_group(struct task_group *tg) { }
| ^~~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:11234:5: warning: no previous prototype for
'alloc_fair_sched_group' [-Wmissing-prototypes]
11234 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
| ^~~~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:11239:6: warning: no previous prototype for
'online_fair_sched_group' [-Wmissing-prototypes]
11239 | void online_fair_sched_group(struct task_group *tg) { }
| ^~~~~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:11241:6: warning: no previous prototype for
'unregister_fair_sched_group' [-Wmissing-prototypes]
11241 | void unregister_fair_sched_group(struct task_group *tg) { }
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c:8429:13: warning: 'update_nohz_stats' defined but not used
[-Wunused-function]
8429 | static bool update_nohz_stats(struct rq *rq)
| ^~~~~~~~~~~~~~~~~
vim +/sched_smt_present +6345 kernel/sched/fair.c
6259
6260 /*
6261 * Try and locate an idle core/thread in the LLC cache domain.
6262 */
6263 static int select_idle_sibling(struct task_struct *p, int prev, int target)
6264 {
6265 bool has_idle_core = false;
6266 struct sched_domain *sd;
6267 unsigned long task_util;
6268 int i, recent_used_cpu;
6269
6270 /*
6271 * On asymmetric system, update task utilization because we will check
6272 * that the task fits with cpu's capacity.
6273 */
6274 if (static_branch_unlikely(&sched_asym_cpucapacity)) {
6275 sync_entity_load_avg(&p->se);
6276 task_util = uclamp_task_util(p);
6277 }
6278
6279 if ((available_idle_cpu(target) || sched_idle_cpu(target)) &&
6280 asym_fits_capacity(task_util, target))
6281 return target;
6282
6283 /*
6284 * If the previous CPU is cache affine and idle, don't be stupid:
6285 */
6286 if (prev != target && cpus_share_cache(prev, target) &&
6287 (available_idle_cpu(prev) || sched_idle_cpu(prev)) &&
6288 asym_fits_capacity(task_util, prev))
6289 return prev;
6290
6291 /*
6292 * Allow a per-cpu kthread to stack with the wakee if the
6293 * kworker thread and the tasks previous CPUs are the same.
6294 * The assumption is that the wakee queued work for the
6295 * per-cpu kthread that is now complete and the wakeup is
6296 * essentially a sync wakeup. An obvious example of this
6297 * pattern is IO completions.
6298 */
6299 if (is_per_cpu_kthread(current) &&
6300 prev == smp_processor_id() &&
6301 this_rq()->nr_running <= 1) {
6302 return prev;
6303 }
6304
6305 /* Check a recently used CPU as a potential idle candidate: */
6306 recent_used_cpu = p->recent_used_cpu;
6307 if (recent_used_cpu != prev &&
6308 recent_used_cpu != target &&
6309 cpus_share_cache(recent_used_cpu, target) &&
6310 (available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu))
&&
6311 cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) &&
6312 asym_fits_capacity(task_util, recent_used_cpu)) {
6313 /*
6314 * Replace recent_used_cpu with prev as it is a potential
6315 * candidate for the next wake:
6316 */
6317 p->recent_used_cpu = prev;
6318 return recent_used_cpu;
6319 }
6320
6321 /*
6322 * For asymmetric CPU capacity systems, our domain of interest is
6323 * sd_asym_cpucapacity rather than sd_llc.
6324 */
6325 if (static_branch_unlikely(&sched_asym_cpucapacity)) {
6326 sd = rcu_dereference(per_cpu(sd_asym_cpucapacity, target));
6327 /*
6328 * On an asymmetric CPU capacity system where an exclusive
6329 * cpuset defines a symmetric island (i.e. one unique
6330 * capacity_orig value through the cpuset), the key will be set
6331 * but the CPUs within that cpuset will not have a domain with
6332 * SD_ASYM_CPUCAPACITY. These should follow the usual symmetric
6333 * capacity path.
6334 */
6335 if (sd) {
6336 i = select_idle_capacity(p, sd, target);
6337 return ((unsigned)i < nr_cpumask_bits) ? i : target;
6338 }
6339 }
6340
6341 sd = rcu_dereference(per_cpu(sd_llc, target));
6342 if (!sd)
6343 return target;
6344
6345 if (static_branch_likely(&sched_smt_present)) {
6346 has_idle_core = test_idle_cores(target, false);
6347
6348 if (!has_idle_core && cpus_share_cache(prev, target)) {
6349 i = select_idle_smt(p, sd, prev);
6350 if ((unsigned int)i < nr_cpumask_bits)
6351 return i;
6352 }
6353 }
6354
6355 i = select_idle_cpu(p, sd, has_idle_core, target);
6356 if ((unsigned)i < nr_cpumask_bits)
6357 return i;
6358
6359 return target;
6360 }
6361
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org