Re: [Qemu-devel] [PATCH] Call MADV_HUGEPAGE for guest RAM allocations

[Michael Tokarev <mjt@tls.msk.ru>]

On 15.10.2012 22:57, Luiz Capitulino wrote:
> On Fri, 5 Oct 2012 16:47:57 -0300
> Luiz Capitulino <lcapitulino@redhat.com> wrote:
> 
>> This makes it possible for QEMU to use transparent huge pages (THP)
>> when transparent_hugepage/enabled=madvise. Otherwise THP is only
>> used when it's enabled system wide.
>>
>> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> 
> ping?
> 
>> ---
>>  exec.c  | 1 +
>>  osdep.h | 5 +++++
>>  2 files changed, 6 insertions(+)
>>
>> diff --git a/exec.c b/exec.c
>> index 1114a09..7504909 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -2584,6 +2584,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
>>      cpu_physical_memory_set_dirty_range(new_block->offset, size, 0xff);
>>  
>>      qemu_ram_setup_dump(new_block->host, size);
>> +    qemu_madvise(new_block->host, size, QEMU_MADV_HUGEPAGE);

FWIW, there was another attempt to do something like this:

https://lists.gnu.org/archive/html/qemu-devel/2012-08/msg02870.html

I'm not sure it is right or not, I just tried to guess, but that one
also went unanswered.  Maybe you will have better luck.

Thanks,

/mjt