On Tue, Aug 18, 2020 at 02:44:34PM +0800, kernel test robot wrote:
> Hi Paul,
>
> First bad commit (maybe != root cause):
Stephen Rothwell beat you to this one, but yes, it is a real bug.
I have queued a fix and will rebase it in later today.
Thank you for your testing efforts!
Thanx, Paul
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
> rcu/next
> head: 398b53b5b3751726c05f14a4331b0de258c0453a
> commit: a20b5bd09813bc981ab0bb01cfd7672017f8d74e [125/128] rcuperf: Change
> rcuperf to rcuscale
> config: x86_64-allyesconfig (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> reproduce (this is a W=1 build):
> git checkout a20b5bd09813bc981ab0bb01cfd7672017f8d74e
> # save the attached .config to linux build tree
> make W=1 ARCH=x86_64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <l...@intel.com>
>
> All errors (new ones prefixed by >>):
>
> In file included from include/linux/kernel.h:15,
> from kernel/rcu/rcuscale.c:13:
> kernel/rcu/rcuscale.c: In function 'rcu_scale_writer':
> >> kernel/rcu/rcuscale.c:430:6: error: 'perf_type' undeclared (first use in
> >> this function); did you mean 'kernfs_type'?
> 430 | perf_type, PERF_FLAG, me, MIN_MEAS);
> | ^~~~~~~~~
> include/linux/printk.h:319:35: note: in definition of macro 'pr_alert'
> 319 | printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> | ^~~~~~~~~~~
> kernel/rcu/rcuscale.c:430:6: note: each undeclared identifier is reported
> only once for each function it appears in
> 430 | perf_type, PERF_FLAG, me, MIN_MEAS);
> | ^~~~~~~~~
> include/linux/printk.h:319:35: note: in definition of macro 'pr_alert'
> 319 | printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> | ^~~~~~~~~~~
> >> kernel/rcu/rcuscale.c:430:17: error: 'PERF_FLAG' undeclared (first use in
> >> this function)
> 430 | perf_type, PERF_FLAG, me, MIN_MEAS);
> | ^~~~~~~~~
> include/linux/printk.h:319:35: note: in definition of macro 'pr_alert'
> 319 | printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> | ^~~~~~~~~~~
> >> kernel/rcu/rcuscale.c:431:27: error: 'n_rcu_perf_writer_finished'
> >> undeclared (first use in this function); did you mean
> >> 'n_rcu_scale_writer_finished'?
> 431 | if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~
> | n_rcu_scale_writer_finished
>
> #
> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=a20b5bd09813bc981ab0bb01cfd7672017f8d74e
> git remote add rcu
> https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
> git fetch --no-tags rcu rcu/next
> git checkout a20b5bd09813bc981ab0bb01cfd7672017f8d74e
> vim +430 kernel/rcu/rcuscale.c
>
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 353
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 354
> /*
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 355
> * RCU scale writer kthread. Repeatedly does a grace period.
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 356
> */
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 357
> static int
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 358
> rcu_scale_writer(void *arg)
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 359
> {
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 360
> int i = 0;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 361
> int i_max;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 362
> long me = (long)arg;
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 363
> struct rcu_head *rhp = NULL;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 364
> bool started = false, done = false, alldone = false;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 365
> u64 t;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 366
> u64 *wdp;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 367
> u64 *wdpp = writer_durations[me];
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 368
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 369
> VERBOSE_SCALEOUT_STRING("rcu_scale_writer task started");
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 370
> WARN_ON(!wdpp);
> 6b558c4c7a4ba4 kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-12 371
> set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
> b1433395c4cc07 kernel/rcu/rcuperf.c Peter Zijlstra 2020-04-21 372
> sched_set_fifo_low(current);
> df37e66bfdbb57 kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-30 373
> df37e66bfdbb57 kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-30 374
> if (holdoff)
> df37e66bfdbb57 kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-30 375
> schedule_timeout_uninterruptible(holdoff * HZ);
> df37e66bfdbb57 kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-30 376
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 377)
> /*
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 378)
> * Wait until rcu_end_inkernel_boot() is called for normal GP tests
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 379)
> * so that RCU is not always expedited for normal GP tests.
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 380)
> * The system_state test is approximate, but works well in practice.
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 381)
> */
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 382)
> while (!gp_exp && system_state != SYSTEM_RUNNING)
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 383)
> schedule_timeout_uninterruptible(1);
> 77e9752ce69f36 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-07-04 384)
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 385
> t = ktime_get_mono_fast_ns();
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 386
> if (atomic_inc_return(&n_rcu_scale_writer_started) >= nrealwriters) {
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 387
> t_rcu_scale_writer_started = t;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 388
> if (gp_exp) {
> e6e78b004fa7e0 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-08-30 389)
> b_rcu_gp_test_started =
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 390
> cur_ops->exp_completed() / 2;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 391
> } else {
> e6e78b004fa7e0 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-08-30 392)
> b_rcu_gp_test_started = cur_ops->get_gp_seq();
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 393
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 394
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 395
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 396
> do {
> 820687a7b98a50 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-25 397
> if (writer_holdoff)
> 820687a7b98a50 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-25 398
> udelay(writer_holdoff);
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 399
> wdp = &wdpp[i];
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 400
> *wdp = ktime_get_mono_fast_ns();
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 401
> if (gp_async) {
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 402
> retry:
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 403
> if (!rhp)
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 404
> rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 405
> if (rhp &&
> atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 406
> atomic_inc(this_cpu_ptr(&n_async_inflight));
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 407
> cur_ops->async(rhp, rcu_scale_async_cb);
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 408
> rhp = NULL;
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 409
> } else if (!kthread_should_stop()) {
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 410
> cur_ops->gp_barrier();
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 411
> goto retry;
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 412
> } else {
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 413
> kfree(rhp); /* Because we are stopping. */
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 414
> }
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 415
> } else if (gp_exp) {
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 416
> cur_ops->exp_sync();
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 417
> } else {
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 418
> cur_ops->sync();
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 419
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 420
> t = ktime_get_mono_fast_ns();
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 421
> *wdp = t - *wdp;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 422
> i_max = i;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 423
> if (!started &&
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 424
> atomic_read(&n_rcu_scale_writer_started) >= nrealwriters)
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 425
> started = true;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 426
> if (!done && i >= MIN_MEAS) {
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 427
> done = true;
> b1433395c4cc07 kernel/rcu/rcuperf.c Peter Zijlstra 2020-04-21 428
> sched_set_normal(current, 0);
> a56fefa2605cf8 kernel/rcu/rcuperf.c SeongJae Park 2016-08-21 429
> pr_alert("%s%s rcu_perf_writer %ld has %d
> measurements\n",
> a56fefa2605cf8 kernel/rcu/rcuperf.c SeongJae Park 2016-08-21 @430
> perf_type, PERF_FLAG, me, MIN_MEAS);
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 @431
> if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 432
> nrealwriters) {
> 620316e52a9238 kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-30 433
> schedule_timeout_interruptible(10);
> ac2bb275e8e5ab kernel/rcu/rcuperf.c Paul E. McKenney 2016-01-29 434
> rcu_ftrace_dump(DUMP_ALL);
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 435
> SCALEOUT_STRING("Test complete");
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 436
> t_rcu_scale_writer_finished = t;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 437
> if (gp_exp) {
> e6e78b004fa7e0 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-08-30 438)
> b_rcu_gp_test_finished =
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 439
> cur_ops->exp_completed() / 2;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 440
> } else {
> e6e78b004fa7e0 kernel/rcu/rcuperf.c Joel Fernandes (Google 2019-08-30 441)
> b_rcu_gp_test_finished =
> 17ef2fe97c8c8e kernel/rcu/rcuperf.c Paul E. McKenney 2018-04-27 442
> cur_ops->get_gp_seq();
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 443
> }
> e6fb1fc1085e5b kernel/rcu/rcuperf.c Artem Savkov 2016-02-07 444
> if (shutdown) {
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 445
> smp_mb(); /* Assign before wake. */
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 446
> wake_up(&shutdown_wq);
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 447
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 448
> }
> e6fb1fc1085e5b kernel/rcu/rcuperf.c Artem Savkov 2016-02-07 449
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 450
> if (done && !alldone &&
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 451
> atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters)
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 452
> alldone = true;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 453
> if (started && !alldone && i < MAX_MEAS - 1)
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 454
> i++;
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 455
> rcu_scale_wait_shutdown();
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 456
> } while (!torture_must_stop());
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 457
> if (gp_async) {
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 458
> cur_ops->gp_barrier();
> 881ed593a323c8 kernel/rcu/rcuperf.c Paul E. McKenney 2017-04-17 459
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 460
> writer_n_durations[me] = i_max;
> a20b5bd09813bc kernel/rcu/rcuscale.c Paul E. McKenney 2020-08-11 461
> torture_kthread_stopping("rcu_scale_writer");
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 462
> return 0;
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 463
> }
> 8704baab9bc848 kernel/rcu/rcuperf.c Paul E. McKenney 2015-12-31 464
>
> :::::: The code at line 430 was first introduced by commit
> :::::: a56fefa2605cf8e125ef09451487f30336128028 rcuperf: Consistently insert
> space between flag and message
>
> :::::: TO: SeongJae Park <sj38.p...@gmail.com>
> :::::: CC: Paul E. McKenney <paul...@linux.vnet.ibm.com>
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
