On 8/15/23 19:18, kernel test robot wrote:
Hi Waiman,
kernel test robot noticed the following build warnings:
[auto build test WARNING on next-20230815]
[cannot apply to tj-cgroup/for-next v6.5-rc6 v6.5-rc5 v6.5-rc4 linus/master v6.5-rc6]
[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/Waiman-Long/cgroup-cpuset-Add-cpuset-cpus-exclusive-effective-for-v2/20230815-233522
base: next-20230815
patch link: https://lore.kernel.org/r/20230815153027.633355-2-longman%40redhat.com
patch subject: [PATCH-cgroup v6 1/6] cgroup/cpuset: Add cpuset.cpus.exclusive.effective for v2
config: parisc64-defconfig (https://download.01.org/0day-ci/archive/20230816/202308160752.IWyhJoln-lkp@xxxxxxxxx/config)
compiler: hppa-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230816/202308160752.IWyhJoln-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308160752.IWyhJoln-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
kernel/cgroup/cpuset.c: In function 'update_prstate':
kernel/cgroup/cpuset.c:2468:30: warning: the comparison will always evaluate as 'true' for the address of 'effective_xcpus' will never be NULL [-Waddress]
2468 | if ((new_prs > 0) && !cs->effective_xcpus) {
Thanks for catching that. It is a careless mistake. Will send out a fix
version.
Cheers,
Longman
| ^
kernel/cgroup/cpuset.c:135:23: note: 'effective_xcpus' declared here
135 | cpumask_var_t effective_xcpus;
| ^~~~~~~~~~~~~~~
vim +2468 kernel/cgroup/cpuset.c
2435
2436 /**
2437 * update_prstate - update partition_root_state
2438 * @cs: the cpuset to update
2439 * @new_prs: new partition root state
2440 * Return: 0 if successful, != 0 if error
2441 *
2442 * Call with cpuset_mutex held.
2443 */
2444 static int update_prstate(struct cpuset *cs, int new_prs)
2445 {
2446 int err = PERR_NONE, old_prs = cs->partition_root_state;
2447 struct tmpmasks tmpmask;
2448
2449 if (old_prs == new_prs)
2450 return 0;
2451
2452 /*
2453 * For a previously invalid partition root, leave it at being
2454 * invalid if new_prs is not "member".
2455 */
2456 if (new_prs && is_prs_invalid(old_prs)) {
2457 cs->partition_root_state = -new_prs;
2458 return 0;
2459 }
2460
2461 if (alloc_cpumasks(NULL, &tmpmask))
2462 return -ENOMEM;
2463
2464 /*
2465 * Setup effective_xcpus if not set yet, it will be cleared later
2466 * if partition becomes invalid.
2467 */
2468 if ((new_prs > 0) && !cs->effective_xcpus) {
2469 struct cpuset *parent = parent_cs(cs);
2470
2471 spin_lock_irq(&callback_lock);
2472 cpumask_and(cs->effective_xcpus,
2473 cs->cpus_allowed, parent->effective_xcpus);
2474 spin_unlock_irq(&callback_lock);
2475 }
2476
2477 err = update_partition_exclusive(cs, new_prs);
2478 if (err)
2479 goto out;
2480
2481 if (!old_prs) {
2482 /*
2483 * cpus_allowed cannot be empty.
2484 */
2485 if (cpumask_empty(cs->cpus_allowed)) {
2486 err = PERR_CPUSEMPTY;
2487 goto out;
2488 }
2489
2490 err = update_parent_effective_cpumask(cs, partcmd_enable,
2491 NULL, &tmpmask);
2492 } else if (old_prs && new_prs) {
2493 /*
2494 * A change in load balance state only, no change in cpumasks.
2495 */
2496 ;
2497 } else {
2498 /*
2499 * Switching back to member is always allowed even if it
2500 * disables child partitions.
2501 */
2502 update_parent_effective_cpumask(cs, partcmd_disable, NULL,
2503 &tmpmask);
2504
2505 /*
2506 * Invalidation of child partitions will be done in
2507 * update_cpumasks_hier().
2508 */
2509 }
2510 out:
2511 /*
2512 * Make partition invalid & disable CS_CPU_EXCLUSIVE if an error
2513 * happens.
2514 */
2515 if (err) {
2516 new_prs = -new_prs;
2517 update_partition_exclusive(cs, new_prs);
2518 }
2519
2520 spin_lock_irq(&callback_lock);
2521 cs->partition_root_state = new_prs;
2522 WRITE_ONCE(cs->prs_err, err);
2523 if (!is_partition_valid(cs))
2524 cpumask_clear(cs->effective_xcpus);
2525 spin_unlock_irq(&callback_lock);
2526
2527 /* Force update if switching back to member */
2528 update_cpumasks_hier(cs, &tmpmask, !new_prs ? HIER_CHECKALL : 0);
2529
2530 /* Update sched domains and load balance flag */
2531 update_partition_sd_lb(cs, old_prs);
2532
2533 notify_partition_change(cs, old_prs);
2534 free_cpumasks(NULL, &tmpmask);
2535 return 0;
2536 }
2537
