Re: [PATCH] Remove acpi_memory_info->failed bit
From: Toshi Kani
Date: Tue Mar 19 2013 - 11:15:20 EST
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 http://marc.info/?l=linux-acpi&m=135769405622667&w=2 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
> >> correct?"
> >> 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)
> >> continue;
> >> }
> >> - 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.
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