From afb5519fdb346201728040cab4e08ce53e7ff4fd Mon Sep 17 00:00:00 2001
From: John Allen <jallen@linux.vnet.ibm.com>
Date: Wed, 23 Aug 2017 12:18:43 -0500
Subject: [PATCH] powerpc/pseries: Don't attempt to acquire drc during memory
hot add for assigned lmbs
References: FATE#322022, bsc#1065729
Patch-mainline: v4.14-rc1
Git-commit: afb5519fdb346201728040cab4e08ce53e7ff4fd
Check if an LMB is assigned before attempting to call dlpar_acquire_drc
in order to avoid any unnecessary rtas calls. This substantially
reduces the running time of memory hot add on lpars with large amounts
of memory.
[mpe: We need to explicitly set rc to 0 in the success case, otherwise
the compiler might think we use rc without initialising it.]
Fixes: c21f515c7436 ("powerpc/pseries: Make the acquire/release of the drc for memory a seperate step")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/platforms/pseries/hotplug-memory.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 9e3afd238d34..1d48ab424bd9 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -828,6 +828,9 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add, struct property *prop)
return -EINVAL;
for (i = 0; i < num_lmbs && lmbs_to_add != lmbs_added; i++) {
+ if (lmbs[i].flags & DRCONF_MEM_ASSIGNED)
+ continue;
+
rc = dlpar_acquire_drc(lmbs[i].drc_index);
if (rc)
continue;
@@ -870,6 +873,7 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add, struct property *prop)
lmbs[i].base_addr, lmbs[i].drc_index);
lmbs[i].reserved = 0;
}
+ rc = 0;
}
return rc;
--
2.10.2