Description
In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec() I am seeing some rcu_tasks stalls in the Meta fleet during reclaim. INFO: rcu_tasks detected stalls on tasks: 0000000088620d09: .. nvcsw: 6735/6735 holdout: 1 idle_cpu: -1/8 task:GlobalCPUThread state:R running task pid:2552016 tgid:2524552 Call Trace: shrink_lruvec mem_cgroup_iter shrink_node do_try_to_free_pages try_to_free_pages __alloc_frozen_pages_noprof alloc_pages_noprof pte_alloc_one __pte_alloc handle_mm_fault Nothing promises direct reclaim returns in bounded time, and the scan loop in shrink_lruvec() only calls cond_resched(), which is a no-op on PREEMPTION kernels. Involuntary preemption is not a Tasks-RCU quiescent state, so the reclaiming task never reports one and becomes a holdout. Upgrade it to cond_resched_tasks_rcu_qs(), which reports a quiescent state even when cond_resched() does nothing. PS: This has been discussed in [1]
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
8315f42295d2667a7f942f154b73a86fd7cb2227 to < 4f50593c9cbc883d8c9b50148a3e8a8b1fd35f57affected8315f42295d2667a7f942f154b73a86fd7cb2227 to < 4cdc1bdf40944de5c6b118fef07ad23f07844338affected8315f42295d2667a7f942f154b73a86fd7cb2227 to < a67a00a70a7c8309ca47ea157ef3e8ed3d268f5baffected8315f42295d2667a7f942f154b73a86fd7cb2227 to < 029c9408049f7f582230322057b7075bea594fd5affected8315f42295d2667a7f942f154b73a86fd7cb2227 to < b5391676c61d94ffe3272dcf6723738b802f79e8affected8315f42295d2667a7f942f154b73a86fd7cb2227 to < 3fd50239986302cb050d3649351bcec00fa9d5abaffected8315f42295d2667a7f942f154b73a86fd7cb2227 to < cf3ba0911a1cf8680371ff113b90088edd01d2bbaffected8315f42295d2667a7f942f154b73a86fd7cb2227 to < 25f52e81216884a7444bf07a606691feb09a94e3affected
Linux Linux
Default version status: affected
3.18affected0 to < 3.18unaffected5.10.270 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.109 to ≤ 6.12.*unaffected6.18.50 to ≤ 6.18.*unaffected7.2.4 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/4f50593c9cbc883d8c9b50148a3e8a8b1fd35f57 ↗
- https://git.kernel.org/stable/c/4cdc1bdf40944de5c6b118fef07ad23f07844338 ↗
- https://git.kernel.org/stable/c/a67a00a70a7c8309ca47ea157ef3e8ed3d268f5b ↗
- https://git.kernel.org/stable/c/029c9408049f7f582230322057b7075bea594fd5 ↗
- https://git.kernel.org/stable/c/b5391676c61d94ffe3272dcf6723738b802f79e8 ↗
- https://git.kernel.org/stable/c/3fd50239986302cb050d3649351bcec00fa9d5ab ↗
- https://git.kernel.org/stable/c/cf3ba0911a1cf8680371ff113b90088edd01d2bb ↗
- https://git.kernel.org/stable/c/25f52e81216884a7444bf07a606691feb09a94e3 ↗