On Mon, Mar 6, 2017 at 2:30 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> From: Michal Hocko <mhocko@xxxxxxxx>
>
> vhost code uses __GFP_REPEAT when allocating vhost_virtqueue resp.
> vhost_vsock because it would really like to prefer kmalloc to the
> vmalloc fallback - see 23cc5a991c7a ("vhost-net: extend device
> allocation to vmalloc") for more context. Michael Tsirkin has also
> noted:
> "
> __GFP_REPEAT overhead is during allocation time. Using vmalloc means all
> accesses are slowed down. Allocation is not on data path, accesses are.
> "
>
> The similar applies to other vhost_kvzalloc users.
>
> Let's teach kvmalloc_node to handle __GFP_REPEAT properly. There are two
> things to be careful about. First we should prevent from the OOM killer
> and so have to involve __GFP_NORETRY by default and secondly override
> __GFP_REPEAT for !costly order requests as the __GFP_REPEAT is ignored
> for !costly orders.
>
> Supporting __GFP_REPEAT like semantic for !costly request is possible
> it would require changes in the page allocator. This is out of scope of
> this patch.
>
> This patch shouldn't introduce any functional change.
>
> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> drivers/vhost/net.c | 9 +++------
> drivers/vhost/vhost.c | 15 +++------------
> drivers/vhost/vsock.c | 9 +++------
> mm/util.c | 20 ++++++++++++++++----
> 4 files changed, 25 insertions(+), 28 deletions(-)
>
There is a kzalloc/vzalloc call in
drivers/vhost/scsi.c:vhost_scsi_open() which is not converted to
kvzalloc(). Was that intentional?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
