2020-06-09 11:43:06

by Satheesh Rajendran

Subject: [PATCH] powerpc/pseries/svm: Fixup align argument in alloc_shared_lppaca() function

Argument "align" in alloc_shared_lppaca() function was unused inside the
function. Let's fix it and update code comment.

Cc: [email protected]
Cc: Thiago Jung Bauermann <[email protected]>
Cc: Ram Pai <[email protected]>
Cc: Sukadev Bhattiprolu <[email protected]>
Cc: Laurent Dufour <[email protected]>
Signed-off-by: Satheesh Rajendran <[email protected]>
---
arch/powerpc/kernel/paca.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 8d96169c597e..9088e107fb43 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -70,7 +70,7 @@ static void *__init alloc_shared_lppaca(unsigned long size, unsigned long align,

shared_lppaca =
memblock_alloc_try_nid(shared_lppaca_total_size,
- PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
+ align, MEMBLOCK_LOW_LIMIT,
limit, NUMA_NO_NODE);
if (!shared_lppaca)
panic("cannot allocate shared data");
@@ -122,7 +122,14 @@ 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);
+ /*
+ * 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.
+ */
+ lp = alloc_shared_lppaca(LPPACA_SIZE, PAGE_SIZE, limit, cpu);
else
lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);

--
2.26.2

2020-06-10 04:22:06

by Thiago Jung Bauermann

Subject: Re: [PATCH] powerpc/pseries/svm: Fixup align argument in alloc_shared_lppaca() function

Satheesh Rajendran <[email protected]> writes:

> Argument "align" in alloc_shared_lppaca() function was unused inside the
> function. Let's fix it and update code comment.
>
> Cc: [email protected]
> Cc: Thiago Jung Bauermann <[email protected]>
> Cc: Ram Pai <[email protected]>
> Cc: Sukadev Bhattiprolu <[email protected]>
> Cc: Laurent Dufour <[email protected]>
> Signed-off-by: Satheesh Rajendran <[email protected]>
> ---
> arch/powerpc/kernel/paca.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)

Nice. I agree it's a good code cleanup.

Reviewed-by: Thiago Jung Bauermann <[email protected]>

--
Thiago Jung Bauermann
IBM Linux Technology Center

2020-06-10 11:27:02

by Michael Ellerman

Subject: Re: [PATCH] powerpc/pseries/svm: Fixup align argument in alloc_shared_lppaca() function

Satheesh Rajendran <[email protected]> writes:
> Argument "align" in alloc_shared_lppaca() function was unused inside the
> function. Let's fix it and update code comment.

I think it would be better to drop the align argument entirely and keep
that logic, and the comment, internal to alloc_shared_lppaca().

cheers