From patchwork Fri Oct 5 19:47:57 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Call MADV_HUGEPAGE for guest RAM allocations Date: Fri, 05 Oct 2012 09:47:57 -0000 From: Luiz Capitulino X-Patchwork-Id: 189589 Message-Id: <20121005164758.4808b2d1@doriath.home> To: qemu-devel Cc: aarcange@redhat.com, jan.kiszka@siemens.com 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 --- 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); if (kvm_enabled()) kvm_setup_guest_memory(new_block->host, size); diff --git a/osdep.h b/osdep.h index cb213e0..c5fd3d9 100644 --- a/osdep.h +++ b/osdep.h @@ -108,6 +108,11 @@ void qemu_vfree(void *ptr); #else #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID #endif +#ifdef MADV_HUGEPAGE +#define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE +#else +#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID +#endif #elif defined(CONFIG_POSIX_MADVISE)