[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3
From: |
Paul Brook |
Subject: |
Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3 |
Date: |
Wed, 17 Mar 2010 15:21:26 +0000 |
User-agent: |
KMail/1.12.4 (Linux/2.6.32-trunk-amd64; KDE/4.3.4; x86_64; ; ) |
> On Wed, Mar 17, 2010 at 03:05:57PM +0000, Paul Brook wrote:
> > > + if (size >= PREFERRED_RAM_ALIGN)
> > > + new_block->host = qemu_memalign(PREFERRED_RAM_ALIGN,
> > > size);
> >
> > Is this deliberately bigger-than rather than multiple-of?
> > Having the size not be a multiple of alignment seems somewhat strange,
> > it's always going to be wrong at one end...
>
> Size not multiple I think is legitimate, the below-4G chunk isn't
> required to end 2M aligned, all it matters is that the above-4G then
> starts aligned. In short one thing to add in the future as parameter
> to qemu_ram_alloc is the physical address that the host virtual
> address corresponds to.
In general you don't know this at allocation time.
> The guest physical address that the host
> retval corresponds to, has to be aligned with PREFERRED_RAM_ALIGN for
> NPT/EPT to work. I don't think it's a big concern right now.
If you allocating chinks that are multiples of the relevant page size, then I
don't think you can expect anything particularly sensible to happen.
Paul
- [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Andrea Arcangeli, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Paul Brook, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Andrea Arcangeli, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3,
Paul Brook <=
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Andrea Arcangeli, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Paul Brook, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Andrea Arcangeli, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Paul Brook, 2010/03/17
- Re: [Qemu-devel] [PATCH QEMU] Transparent Hugepage Support #3, Andrea Arcangeli, 2010/03/17