Re: [PATCH] Remove acpi_memory_info->failed bit

From: Yasuaki Ishimatsu
Date: Wed Mar 20 2013 - 19:57:29 EST

Hi Toshi,

2013/03/20 0:03, Toshi Kani wrote:
On Mon, 2013-03-18 at 11:19 +0900, Yasuaki Ishimatsu wrote:
Hi Toshi,

Sorry for the late reply

2013/03/13 23:50, Toshi Kani wrote:
On Wed, 2013-03-13 at 15:54 +0900, Yasuaki Ishimatsu wrote:
At thread,
Toshi Kani mentioned as follows:

"I have a question about the change you made in commit 65479472 in
acpi_memhotplug.c. This change seems to require that
acpi_memory_enable_device() calls add_memory() to add all memory ranges
represented by memory device objects at boot-time, and keep the results
be used for hot-remove.

If I understand it right, this add_memory() call fails with EEXIST at
boot-time since all memory ranges should have been added from EFI memory
table (or e820) already. This results all memory ranges be marked as !
enabled & !failed. I think this means that we cannot hot-delete any
memory ranges presented at boot-time since acpi_memory_remove_memory()
only calls remove_memory() when the enabled flag is set. Is that

Above mention is correct. Thus even if memory device supports hotplug,
memory presented at boot-time cannot be hot removed since the memory
device's acpi_memory_info->enabled is always 0.

This patch changes to set 1 to "acpi_memory_info->enabled" of memory
device presented at boot-time for hot removing the memory device.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>

drivers/acpi/acpi_memhotplug.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index da1f82b..88fd46a 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -254,8 +254,8 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)

- if (!result)
- info->enabled = 1;
+ info->enabled = 1;

Do we still need to keep the enable bit? I think !failed means enabled
with this change.

For controlling memory hotplug, we need either failed bit or enabled bit.
So I want to remove failed bit as follows:


acpi_memory_info has enabled bit and failed bit for controlling memory
hotplug. But we don't need to keep both bits.

The patch removes acpi_memory_info->failed bit.

Thanks for the update. Which branch does this patch apply to? I tried
several, but could not apply.

These patches are based on linux-3.9-rc3.
O.K. I'll make them based on linux-pm.git/bleeding-edge.

Yasuaki Ishimatsu


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