On Tue, Sep 23, 2014 at 11:30:26AM +0300, Michael S. Tsirkin wrote:
> On Tue, Sep 23, 2014 at 03:57:47PM +0800, zhanghailiang wrote:
> > If we configure mlock=on and memory policy=bind at the same time,
> > It will consume lots of time for system to treat with memory,
> > especially when call mbind after mlockall.
> >
> > Adjust the place of calling mlockall, calling mbind before mlockall
> > can remarkably reduce the time of VM's startup.
> >
> > Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
>
> The idea makes absolute sense to me:
> bind after lock will force data copy of
> all pages. bind before lock gives us an
> indication where to put data on fault in.
Agreed.
>
> Acked-by: Michael S. Tsirkin <m...@redhat.com>
>
>
> > ---
> > Hi,
> >
> > Actually, for mbind and mlockall, i have made a test about the time
> > consuming
> > for the different call sequence.
> >
> > The results is shown below. It is obviously that mlockall called before
> > mbind is
> > more time-consuming.
> >
> > Besides, this patch is OK with memory hotplug.
> >
> > TEST CODE:
> > if (mbind_first) {
> > printf("mbind --> mlockall\n");
> > mbind(ptr, ram_size/2, MPOL_BIND, &node0mask, 2,
> > MPOL_MF_STRICT | MPOL_MF_MOVE);
> > mbind(ptr + ram_size/2, ram_size/2, MPOL_BIND, &node1mask, 2,
> > MPOL_MF_STRICT | MPOL_MF_MOVE);
> > mlockall(MCL_CURRENT | MCL_FUTURE);
> > } else {
> > printf("mlockall --> mbind\n");
> > mlockall(MCL_CURRENT | MCL_FUTURE);
> > mbind(ptr, ram_size/2, MPOL_BIND, &node0mask, 2 ,
> > MPOL_MF_STRICT | MPOL_MF_MOVE);
> > mbind(ptr + ram_size/2, ram_size/2, MPOL_BIND, &node1mask, 2,
> > MPOL_MF_STRICT | MPOL_MF_MOVE);
> > }
> >
> > RESULT 1:
> > #time /home/test_mbind 10240 0
> > memroy size 10737418240
> > mlockall --> mbind
> >
> > real 0m11.886s
> > user 0m0.004s
> > sys 0m11.865s
> > #time /home/test_mbind 10240 1
> > memroy size 10737418240
> > mbind --> mlockall
> >
> > real 0m5.334s
> > user 0m0.000s
> > sys 0m5.324s
> >
> > RESULT 2:
> > #time /home/test_mbind 4096 0
> > memroy size 4294967296
> > mlockall --> mbind
> >
> > real 0m5.503s
> > user 0m0.000s
> > sys 0m5.492s
> > #time /home/test_mbind 4096 1
> > memroy size 4294967296
> > mbind --> mlockall
> >
> > real 0m2.139s
> > user 0m0.000s
> > sys 0m2.132s
> >
> > Best Regards,
> > zhanghailiang
> > ---
> > vl.c | 11 +++++------
> > 1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/vl.c b/vl.c
> > index dc792fe..adf4770 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -134,6 +134,7 @@ const char* keyboard_layout = NULL;
> > ram_addr_t ram_size;
> > const char *mem_path = NULL;
> > int mem_prealloc = 0; /* force preallocation of physical target memory */
> > +int enable_mlock = false;
Why not bool?
Regards,
Hu
