Re: [PATCH V2] powerpc/pseries/svm: Drop unused align argument in alloc_shared_lppaca() function

From: Laurent Dufour
Date: Tue Jun 16 2020 - 04:24:25 EST


Le 12/06/2020 Ã 16:29, Satheesh Rajendran a ÃcritÂ:
Argument "align" in alloc_shared_lppaca() was unused inside the
function. Let's drop it and update code comment for page alignment.

Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx>
Cc: Ram Pai <linuxram@xxxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Cc: Laurent Dufour <ldufour@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Reviewed-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx>

Reviewed-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx>

Signed-off-by: Satheesh Rajendran <sathnaga@xxxxxxxxxxxxxxxxxx>
---

V2:
Added reviewed by Thiago.
Dropped align argument as per Michael suggest.
Modified commit msg.

V1: http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20200609113909.17236-1-sathnaga@xxxxxxxxxxxxxxxxxx/
---
arch/powerpc/kernel/paca.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 8d96169c597e..a174d64d9b4d 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -57,8 +57,8 @@ static void *__init alloc_paca_data(unsigned long size, unsigned long align,
#define LPPACA_SIZE 0x400
-static void *__init alloc_shared_lppaca(unsigned long size, unsigned long align,
- unsigned long limit, int cpu)
+static void *__init alloc_shared_lppaca(unsigned long size, unsigned long limit,
+ int cpu)
{
size_t shared_lppaca_total_size = PAGE_ALIGN(nr_cpu_ids * LPPACA_SIZE);
static unsigned long shared_lppaca_size;
@@ -68,6 +68,12 @@ static void *__init alloc_shared_lppaca(unsigned long size, unsigned long align,
if (!shared_lppaca) {
memblock_set_bottom_up(true);
+ /* See Documentation/powerpc/ultravisor.rst for mode details
+ *
+ * UV/HV data share is in PAGE granularity, In order to
+ * minimize the number of pages shared and maximize the
+ * use of a page, let's use page align.
+ */
shared_lppaca =
memblock_alloc_try_nid(shared_lppaca_total_size,
PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
@@ -122,7 +128,7 @@ static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
return NULL;
if (is_secure_guest())
- lp = alloc_shared_lppaca(LPPACA_SIZE, 0x400, limit, cpu);
+ lp = alloc_shared_lppaca(LPPACA_SIZE, limit, cpu);
else
lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);