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a=rsa-sha256; c=relaxed/relaxed; d=baidu.com; s=selector1; t=1773819404; bh=y2YpHlh+WSQL0MG8EwEamlgcCGzhk9KPm0u1wFzft7g=; h=From:To:CC:Subject:Date:Message-ID:Content-Type; b=Pl/QLI09z6s1lj6PvqIwSXzpuBWxixFtMj256R4Y+Im91d5/bJ+HgncZQqkRG45p7 IH5015wTLSL24frGnFyiPsZcPG4PMACqpHaWCCE+IzJycmvVxfHP/6PgrQpCB+u4GF kMPFB1d4KOU/mfOyC8JOVH2ZVV8zX522mhTIQVPZLKap1LCD1dfVoaVU0x4Vqx2d/I qaOJFpmD3iFxlF9VR1GpPz6t7dPIOrZ2aYR4IBbsXPxkUsotUtrRut6AusjE8aX7Y3 aysp47Wr1D3QBDnIT8rdLUO921vlqfl/z/lCWr7GYbzVssGjD/zaVMN6IvBB8YxHmT CkT2FPskJVepg== X-Rspam-User: X-Stat-Signature: m9j5b6bm45jdiupfyt9ewku1xfd5u7ki X-Rspamd-Queue-Id: B9361100016 X-Rspamd-Server: rspam03 X-HE-Tag: 1773819651-325041 X-HE-Meta: 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 0Bv+8RIR qRHcJ2kW0q1JghUXgvRalI8Y+G7CxJx7c+ymB1wkrdVWFlR4e2tqul+0agljcde8ivcKI5aNfeBDmeWRi6I6oTS7yqqElNNxeiqvBKMsTpLXFs7lCuwxIdMd5pWGry1/miIX7qb6QkxF3qa81bpRW1ONMs4WQBTeqUn122MEWiAQpKNsuMhGNVY9xoEfctI4JHrx0MmsC7gntbgD492qjR8az86l6T+HS54hk37ThJ8MB2F7EoPUQ8gMv061SbHH2XVGEjfGhbAM4eXCso4k9+0gV+vuf6IYyL46kOzzctifrAnAhUJ4sapEXiFFHbk0HM25zrS2D7RCDbQc8df9ZcjtLS5MlrUvadJGTIZbA0qB8JAumn1dwY5SvVWLzXcVWvswK Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Li RongQing The workqueue watchdog currently reports that drain_vmap_area_work hogs the CPU for more than 10ms. This typically happens during heavy memory pressure or high-frequency vmap/vunmap operations where the lazy drain list grows large. [ 2069.796205] workqueue: drain_vmap_area_work hogged CPU for >10000us 4 times, consider switching to WQ_UNBOUND [ 2192.823225] workqueue: drain_vmap_area_work hogged CPU for >10000us 5 times, consider switching to WQ_UNBOUND [ 3225.388966] workqueue: drain_vmap_area_work hogged CPU for >10000us 7 times, consider switching to WQ_UNBOUND Since vmap area draining is a background housekeeping task that does not require strict CPU affinity or cache locality, it is a prime candidate for an unbound workqueue. Switching from schedule_work() to queue_work(system_unbound_wq, ...) allows the scheduler to offload the draining process to any available CPU core. This prevents stalling the current CPU and resolves the "consider switching to WQ_UNBOUND" warning. Signed-off-by: Li RongQing --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 61caa55..5f2218a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2471,7 +2471,7 @@ static void free_vmap_area_noflush(struct vmap_area *va) /* After this point, we may free va at any time */ if (unlikely(nr_lazy > nr_lazy_max)) - schedule_work(&drain_vmap_work); + queue_work(system_unbound_wq, &drain_vmap_work); } /* -- 2.9.4