From afb5519fdb346201728040cab4e08ce53e7ff4fd Mon Sep 17 00:00:00 2001 From: John Allen 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 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 Reviewed-by: Nathan Fontenot Signed-off-by: Michael Ellerman --- 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; -- 2.20.1