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authorNathan Lynch <nathanl@linux.ibm.com>2019-04-18 13:56:57 -0500
committerMichael Ellerman <mpe@ellerman.id.au>2019-04-20 22:03:57 +1000
commit2d4d9b308f8f8dec68f6dbbff18c68ec7c6bd26f (patch)
treeedf44b1690bfcf30ea0284ca38fe35862e9afb84
parent2f9196b67237f1e59f2753b2968f8ad6433d4042 (diff)
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powerpc/numa: improve control of topology updates
When booted with "topology_updates=no", or when "off" is written to /proc/powerpc/topology_updates, NUMA reassignments are inhibited for PRRN and VPHN events. However, migration and suspend unconditionally re-enable reassignments via start_topology_update(). This is incoherent. Check the topology_updates_enabled flag in start/stop_topology_update() so that callers of those APIs need not be aware of whether reassignments are enabled. This allows the administrative decision on reassignments to remain in force across migrations and suspensions. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/mm/numa.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index f3ee0e18edd6..952ada44df62 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1497,6 +1497,9 @@ int start_topology_update(void)
{
int rc = 0;
+ if (!topology_updates_enabled)
+ return 0;
+
if (firmware_has_feature(FW_FEATURE_PRRN)) {
if (!prrn_enabled) {
prrn_enabled = 1;
@@ -1530,6 +1533,9 @@ int stop_topology_update(void)
{
int rc = 0;
+ if (!topology_updates_enabled)
+ return 0;
+
if (prrn_enabled) {
prrn_enabled = 0;
#ifdef CONFIG_SMP
@@ -1587,11 +1593,13 @@ static ssize_t topology_write(struct file *file, const char __user *buf,
kbuf[read_len] = '\0';
- if (!strncmp(kbuf, "on", 2))
+ if (!strncmp(kbuf, "on", 2)) {
+ topology_updates_enabled = true;
start_topology_update();
- else if (!strncmp(kbuf, "off", 3))
+ } else if (!strncmp(kbuf, "off", 3)) {
stop_topology_update();
- else
+ topology_updates_enabled = false;
+ } else
return -EINVAL;
return count;
@@ -1606,9 +1614,7 @@ static const struct file_operations topology_ops = {
static int topology_update_init(void)
{
- /* Do not poll for changes if disabled at boot */
- if (topology_updates_enabled)
- start_topology_update();
+ start_topology_update();
if (vphn_enabled)
topology_schedule_update();