Re: [PATCH memcg v4] memcg: prohibit unconditional exceeding the limit of dying tasks

[kernel test robot <lkp@intel.com>]

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Hi Vasily,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on v5.15-rc6]
[cannot apply to hnaz-mm/master next-20211112]
[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]

url:    https://github.com/0day-ci/linux/commits/Vasily-Averin/memcg-prohibit-unconditional-exceeding-the-limit-of-dying-tasks/20211020-160835
base:   DEBUG invalid remote for branch v5.15-rc6 519d81956ee277b4419c723adfb154603c2565ba
config: x86_64-rhel-8.3-kselftests (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/fd30aeb6287dfe68bcf02c4d9634e342d6743d90
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Vasily-Averin/memcg-prohibit-unconditional-exceeding-the-limit-of-dying-tasks/20211020-160835
        git checkout fd30aeb6287dfe68bcf02c4d9634e342d6743d90
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
   mm/memcontrol.c:4088:21: sparse: sparse: incompatible types in comparison expression (different address spaces):
   mm/memcontrol.c:4088:21: sparse:    struct mem_cgroup_threshold_ary [noderef] __rcu *
   mm/memcontrol.c:4088:21: sparse:    struct mem_cgroup_threshold_ary *
   mm/memcontrol.c:4090:21: sparse: sparse: incompatible types in comparison expression (different address spaces):
   mm/memcontrol.c:4090:21: sparse:    struct mem_cgroup_threshold_ary [noderef] __rcu *
   mm/memcontrol.c:4090:21: sparse:    struct mem_cgroup_threshold_ary *
   mm/memcontrol.c:4246:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   mm/memcontrol.c:4246:9: sparse:    struct mem_cgroup_threshold_ary [noderef] __rcu *
   mm/memcontrol.c:4246:9: sparse:    struct mem_cgroup_threshold_ary *
   mm/memcontrol.c:4340:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   mm/memcontrol.c:4340:9: sparse:    struct mem_cgroup_threshold_ary [noderef] __rcu *
   mm/memcontrol.c:4340:9: sparse:    struct mem_cgroup_threshold_ary *
   mm/memcontrol.c:5966:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   mm/memcontrol.c:5966:23: sparse:    struct task_struct [noderef] __rcu *
   mm/memcontrol.c:5966:23: sparse:    struct task_struct *
   mm/memcontrol.c: note: in included file:
   include/linux/memcontrol.h:752:9: sparse: sparse: context imbalance in 'lock_page_lruvec' - wrong count at exit
   include/linux/memcontrol.h:752:9: sparse: sparse: context imbalance in 'lock_page_lruvec_irq' - wrong count at exit
   include/linux/memcontrol.h:752:9: sparse: sparse: context imbalance in 'lock_page_lruvec_irqsave' - wrong count at exit
>> mm/memcontrol.c:1826:70: sparse: sparse: non size-preserving integer to pointer cast
   mm/memcontrol.c:1987:6: sparse: sparse: context imbalance in 'lock_page_memcg' - wrong count at exit
   mm/memcontrol.c:2036:17: sparse: sparse: context imbalance in '__unlock_page_memcg' - unexpected unlock
   mm/memcontrol.c:5817:28: sparse: sparse: context imbalance in 'mem_cgroup_count_precharge_pte_range' - unexpected unlock
   mm/memcontrol.c:6011:36: sparse: sparse: context imbalance in 'mem_cgroup_move_charge_pte_range' - unexpected unlock

vim +1826 mm/memcontrol.c

  1765	
  1766	static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
  1767	{
  1768		enum oom_status ret;
  1769		bool locked;
  1770	
  1771		if (order > PAGE_ALLOC_COSTLY_ORDER)
  1772			return OOM_SKIPPED;
  1773	
  1774		memcg_memory_event(memcg, MEMCG_OOM);
  1775	
  1776		/*
  1777		 * We are in the middle of the charge context here, so we
  1778		 * don't want to block when potentially sitting on a callstack
  1779		 * that holds all kinds of filesystem and mm locks.
  1780		 *
  1781		 * cgroup1 allows disabling the OOM killer and waiting for outside
  1782		 * handling until the charge can succeed; remember the context and put
  1783		 * the task to sleep at the end of the page fault when all locks are
  1784		 * released.
  1785		 *
  1786		 * On the other hand, in-kernel OOM killer allows for an async victim
  1787		 * memory reclaim (oom_reaper) and that means that we are not solely
  1788		 * relying on the oom victim to make a forward progress and we can
  1789		 * invoke the oom killer here.
  1790		 *
  1791		 * Please note that mem_cgroup_out_of_memory might fail to find a
  1792		 * victim and then we have to bail out from the charge path.
  1793		 */
  1794		if (memcg->oom_kill_disable) {
  1795			if (!current->in_user_fault)
  1796				return OOM_SKIPPED;
  1797			css_get(&memcg->css);
  1798			current->memcg_in_oom = memcg;
  1799			current->memcg_oom_gfp_mask = mask;
  1800			current->memcg_oom_order = order;
  1801	
  1802			return OOM_ASYNC;
  1803		}
  1804	
  1805		mem_cgroup_mark_under_oom(memcg);
  1806	
  1807		locked = mem_cgroup_oom_trylock(memcg);
  1808	
  1809		if (locked)
  1810			mem_cgroup_oom_notify(memcg);
  1811	
  1812		mem_cgroup_unmark_under_oom(memcg);
  1813		if (mem_cgroup_out_of_memory(memcg, mask, order)) {
  1814			ret = OOM_SUCCESS;
  1815		} else {
  1816			ret = OOM_FAILED;
  1817			/*
  1818			 * In some rare cases mem_cgroup_out_of_memory() can return false.
  1819			 * If it was called from #PF it forces handle_mm_fault()
  1820			 * return VM_FAULT_OOM and executes pagefault_out_of_memory().
  1821			 * memcg_in_oom is set here to notify pagefault_out_of_memory()
  1822			 * that it was a memcg-related failure and not allow to run
  1823			 * global OOM.
  1824			 */
  1825			if (current->in_user_fault)
> 1826				current->memcg_in_oom = (struct mem_cgroup *)ret;
  1827		}
  1828		if (locked)
  1829			mem_cgroup_oom_unlock(memcg);
  1830	
  1831		return ret;
  1832	}
  1833	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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