[PATCH 1/1] powerpc/pseries: Enable RAS hotplug events late
From: Sam Bobroff <hidden>
Date: 2018-02-12 00:19:39
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Currently if the kernel receives a memory hot-unplug event early enough, it may get stuck in an infinite loop in dissolve_free_huge_pages(). This appears as a stall just after: pseries-hotplug-mem: Attempting to hot-remove XX LMB(s) at YYYYYYYY It appears to be caused by "minimum_order" being uninitialized, due to init_ras_IRQ() executing before hugetlb_init(). To correct this, extract the part of init_ras_IRQ() that enables hotplug event processing and place it in the machine_late_initcall phase, which is guaranteed to be after hugetlb_init() is called. Signed-off-by: Sam Bobroff <redacted> --- arch/powerpc/platforms/pseries/ras.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 81d8614e7379..ba284949af06 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c@@ -66,6 +66,26 @@ static int __init init_ras_IRQ(void) of_node_put(np); } + /* EPOW Events */ + np = of_find_node_by_path("/event-sources/epow-events"); + if (np != NULL) { + request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW"); + of_node_put(np); + } + + return 0; +} +machine_subsys_initcall(pseries, init_ras_IRQ); + +/* + * Enable the hotplug interrupt late because processing them may touch other + * devices or systems (e.g. hugepages) that have not been initialized at the + * subsys stage. + */ +int __init init_ras_hotplug_IRQ(void) +{ + struct device_node *np; + /* Hotplug Events */ np = of_find_node_by_path("/event-sources/hot-plug-events"); if (np != NULL) {
@@ -75,16 +95,9 @@ static int __init init_ras_IRQ(void) of_node_put(np); } - /* EPOW Events */ - np = of_find_node_by_path("/event-sources/epow-events"); - if (np != NULL) { - request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW"); - of_node_put(np); - } - return 0; } -machine_subsys_initcall(pseries, init_ras_IRQ); +machine_late_initcall(pseries, init_ras_hotplug_IRQ); #define EPOW_SHUTDOWN_NORMAL 1 #define EPOW_SHUTDOWN_ON_UPS 2
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2.16.1.74.g9b0b1f47b