head: 66ba79a988fd1e7a3385c7edfed0a29f6e53ca76
commit: 66ba79a988fd1e7a3385c7edfed0a29f6e53ca76 [11/11] autonuma recency fix
config: arm64-defconfig (attached as .config)
compiler: clang version 9.0.0 (git://gitmirror/llvm_project
fee855b5bc1abe1f3f89e977ce4c81cf9bdbc2e4)
reproduce:
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout 66ba79a988fd1e7a3385c7edfed0a29f6e53ca76
# save the attached .config to linux build tree
make.cross ARCH=arm64
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <l...@intel.com>
All error/warnings (new ones prefixed by >>):
kernel/sched/fair.c:1421:41: warning: signed shift result (0x280000000)
requires 35 bits to represent, but 'int' only has 32 bits [-Wshift-overflow]
end = mm->numa_scan_starts[i] + (2560 << 22);
~~~~ ^ ~~
kernel/sched/fair.c:1426:8: error: expected expression
if (long(now - tj) > 250)
^
1 warning and 1 error generated.
vim +1426 kernel/sched/fair.c
1405
1406 bool should_numa_migrate_memory(struct task_struct *p, struct page *
page,
1407 int src_nid, int dst_cpu, unsigned
long addr)
1408 {
1409 struct numa_group *ng = p->numa_group;
1410 int dst_nid = cpu_to_node(dst_cpu);
1411 int last_cpupid, this_cpupid;
1412 struct mm_struct *mm = p->mm;
1413
1414 if (sysctl_numa_balancing_mode == NUMA_BALANCING_HMEM) {
1415 int i, i_start;
1416 unsigned long start, end;
1417 unsigned long now = jiffies, tj;
1418
1419 i = i_start = mm->numa_scan_idx;
1420 smp_rmb();
1421 end = mm->numa_scan_starts[i] + (MAX_SCAN_WINDOW << 22);
1422 do {
1423 tj = mm->numa_scan_jiffies[i];
1424 if (!tj)
1425 return false;
1426 if (long(now - tj) > HZ)
1427 return false;
1428 start = mm->numa_scan_starts[i];
1429 /* Scan pass the end of address space */
1430 if (end < start)
1431 end = TASK_SIZE;
1432 if (addr >= start && addr < end)
1433 return true;
1434 if (i == 0)
1435 i = NUMA_SCAN_NR_HIST - 1;
1436 else
1437 i--;
1438 end = start;
1439 } while (i != i_start);
1440 return false;
1441 }
1442
1443 this_cpupid = cpu_pid_to_cpupid(dst_cpu, current->pid);
1444 last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
1445
1446 /*
1447 * Allow first faults or private faults to migrate immediately
early in
1448 * the lifetime of a task. The magic number 4 is based on
waiting for
1449 * two full passes of the "multi-stage node selection" test
that is
1450 * executed below.
1451 */LKML
1452 if ((p->numa_preferred_nid == NUMA_NO_NODE || p->numa_scan_seq <= 4)
&&
1453 (cpupid_pid_unset(last_cpupid) || cpupid_match_pid(p,
last_cpupid)))
1454 return true;
1455
1456 /*
1457 * Multi-stage node selection is used in conjunction with a
periodic
1458 * migration fault to build a temporal task<->page relation.
By using
1459 * a two-stage filter we remove short/unlikely relations.
1460 *
1461 * Using P(p) ~ n_p / n_t as per frequentist probability, we
can equate
1462 * a task's usage of a particular page (n_p) per total usage
of this
1463 * page (n_t) (in a given time-span) to a probability.
1464 *
1465 * Our periodic faults will sample this probability and
getting the
1466 * same result twice in a row, given these samples are fully
1467 * independent, is then given by P(n)^2, provided our sample
period
1468 * is sufficiently short compared to the usage pattern.
1469 *
1470 * This quadric squishes small probabilities, making it less
likely we
1471 * act on an unlikely task<->page relation.
1472 */
1473 if (!cpupid_pid_unset(last_cpupid) &&
1474 cpupid_to_nid(last_cpupid) != dst_nid) {
1475 count_vm_event(NUMA_SHARED);
1476 return false;
1477 }
1478
1479 /* Always allow migrate on private faults */
1480 if (cpupid_match_pid(p, last_cpupid))
1481 return true;
1482
1483 /* A shared fault, but p->numa_group has not been set up yet.
*/
1484 if (!ng)
1485 return true;
1486
1487 /*
1488 * Destination node is much more heavily used than the source
1489 * node? Allow migration.
1490 */
1491 if (group_faults_cpu(ng, dst_nid) > group_faults_cpu(ng,
src_nid) *
1492 ACTIVE_NODE_FRACTION)
1493 return true;
1494
1495 /*
1496 * Distribute memory according to CPU & memory use on each
node,
1497 * with 3/4 hysteresis to avoid unnecessary memory migrations:
1498 *
1499 * faults_cpu(dst) 3 faults_cpu(src)
1500 * --------------- * - > ---------------
1501 * faults_mem(dst) 4 faults_mem(src)
1502 */
1503 return group_faults_cpu(ng, dst_nid) * group_faults(p, src_nid) *
3 >
1504 group_faults_cpu(ng, src_nid) * group_faults(p,
dst_nid) * 4;
1505 }
1506
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