powerpc/numa: improve control of topology updates (2d4d9b30) · Commits · 戴 / test

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>

arch/powerpc/mm/numa.c

+12 −6

Original line number	Diff line number	Diff line
		@@ -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;
		@@ -1606,8 +1614,6 @@ 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();

		if (vphn_enabled)

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