From 65b9fdadfc4d87e2577b791fb3495cd39c93d8c0 Mon Sep 17 00:00:00 2001 From: Michael Bringmann Date: Tue, 9 Oct 2018 15:12:14 -0500 Subject: [PATCH] powerpc/pseries/mobility: Extend start/stop topology update scope The powerpc mobility code may receive RTAS requests to perform PRRN (Platform Resource Reassignment Notification) topology changes at any time, including during LPAR migration operations. In some configurations where the affinity of CPUs or memory is being changed on that platform, the PRRN requests may apply or refer to outdated information prior to the complete update of the device-tree. This patch changes the duration for which topology updates are suppressed during LPAR migrations from just the rtas_ibm_suspend_me() / 'ibm,suspend-me' call(s) to cover the entire migration_store() operation to allow all changes to the device-tree to be applied prior to accepting and applying any PRRN requests. For tracking purposes, pr_info notices are added to the functions start_topology_update() and stop_topology_update() of 'numa.c'. Signed-off-by: Michael Bringmann Reviewed-by: Nathan Fontenot Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/rtas.c | 2 -- arch/powerpc/mm/numa.c | 6 ++++++ arch/powerpc/platforms/pseries/mobility.c | 5 +++++ 3 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 2c7ed31c736e..e02ac377ed64 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -982,7 +982,6 @@ int rtas_ibm_suspend_me(u64 handle) } cpu_hotplug_disable(); - stop_topology_update(); /* Call function on all CPUs. One of us will make the * rtas call @@ -995,7 +994,6 @@ int rtas_ibm_suspend_me(u64 handle) if (atomic_read(&data.error) != 0) printk(KERN_ERR "Error doing global join\n"); - start_topology_update(); cpu_hotplug_enable(); /* Take down CPUs not online prior to suspend */ diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 055b211b7126..693ae1c1acba 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1521,6 +1521,10 @@ int start_topology_update(void) } } + pr_info("Starting topology update%s%s\n", + (prrn_enabled ? " prrn_enabled" : ""), + (vphn_enabled ? " vphn_enabled" : "")); + return rc; } @@ -1542,6 +1546,8 @@ int stop_topology_update(void) rc = del_timer_sync(&topology_timer); } + pr_info("Stopping topology update\n"); + return rc; } diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c index 6f27d00505cf..88925f8ca8a0 100644 --- a/arch/powerpc/platforms/pseries/mobility.c +++ b/arch/powerpc/platforms/pseries/mobility.c @@ -360,6 +360,8 @@ static ssize_t migration_store(struct class *class, if (rc) return rc; + stop_topology_update(); + do { rc = rtas_ibm_suspend_me(streamid); if (rc == -EAGAIN) @@ -370,6 +372,9 @@ static ssize_t migration_store(struct class *class, return rc; post_mobility_fixup(); + + start_topology_update(); + return count; } -- 2.30.2