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authorHaren Myneni <haren@linux.ibm.com>2022-03-19 02:28:09 -0700
committerMichael Ellerman <mpe@ellerman.id.au>2022-05-04 22:00:47 +1000
commit57831bfb5e78777dc399e351ed68ef77c3aee385 (patch)
tree975073b1bf63c13cb586fb134f6650e62d45992f /arch/powerpc/platforms/pseries/vas-sysfs.c
parentbb82c574691daf8f7fa9a160264d15c5804cb769 (diff)
powerpc/pseries/vas: Use QoS credits from the userspace
The user can change the QoS credits dynamically with the management console interface which notifies OS with sysfs. After returning from the OS interface successfully, the management console updates the hypervisor. Since the VAS capabilities in the hypervisor is not updated when the OS gets the update, the kernel is using the old total credits value from the hypervisor. Fix this issue by using the new QoS credits from the userspace instead of depending on VAS capabilities from the hypervisor. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/76d156f8af1e03cc09369d68e0bfad0c40031bcc.camel@linux.ibm.com
Diffstat (limited to 'arch/powerpc/platforms/pseries/vas-sysfs.c')
-rw-r--r--arch/powerpc/platforms/pseries/vas-sysfs.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/arch/powerpc/platforms/pseries/vas-sysfs.c b/arch/powerpc/platforms/pseries/vas-sysfs.c
index 909535ca513a..ec65586cbeb3 100644
--- a/arch/powerpc/platforms/pseries/vas-sysfs.c
+++ b/arch/powerpc/platforms/pseries/vas-sysfs.c
@@ -27,22 +27,31 @@ struct vas_caps_entry {
/*
* This function is used to get the notification from the drmgr when
- * QoS credits are changed. Though receiving the target total QoS
- * credits here, get the official QoS capabilities from the hypervisor.
+ * QoS credits are changed.
*/
-static ssize_t update_total_credits_trigger(struct vas_cop_feat_caps *caps,
+static ssize_t update_total_credits_store(struct vas_cop_feat_caps *caps,
const char *buf, size_t count)
{
int err;
u16 creds;
err = kstrtou16(buf, 0, &creds);
+ /*
+ * The user space interface from the management console
+ * notifies OS with the new QoS credits and then the
+ * hypervisor. So OS has to use this new credits value
+ * and reconfigure VAS windows (close or reopen depends
+ * on the credits available) instead of depending on VAS
+ * QoS capabilities from the hypervisor.
+ */
if (!err)
- err = vas_reconfig_capabilties(caps->win_type);
+ err = vas_reconfig_capabilties(caps->win_type, creds);
if (err)
return -EINVAL;
+ pr_info("Set QoS total credits %u\n", creds);
+
return count;
}
@@ -92,7 +101,7 @@ VAS_ATTR_RO(nr_total_credits);
VAS_ATTR_RO(nr_used_credits);
static struct vas_sysfs_entry update_total_credits_attribute =
- __ATTR(update_total_credits, 0200, NULL, update_total_credits_trigger);
+ __ATTR(update_total_credits, 0200, NULL, update_total_credits_store);
static struct attribute *vas_def_capab_attrs[] = {
&nr_total_credits_attribute.attr,