Messages in this thread | | | Subject | Re: [virtio-dev] Re: [PATCH v2] virtio_balloon: export hugetlb page allocation counts | From | Jason Wang <> | Date | Fri, 13 Apr 2018 15:01:11 +0800 |
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On 2018年04月12日 08:24, Jonathan Helman wrote: > > > On 04/10/2018 08:12 PM, Jason Wang wrote: >> >> >> On 2018年04月10日 05:11, Jonathan Helman wrote: >>> >>> >>> On 03/22/2018 07:38 PM, Jason Wang wrote: >>>> >>>> >>>> On 2018年03月22日 11:10, Michael S. Tsirkin wrote: >>>>> On Thu, Mar 22, 2018 at 09:52:18AM +0800, Jason Wang wrote: >>>>>> On 2018年03月20日 12:26, Jonathan Helman wrote: >>>>>>>> On Mar 19, 2018, at 7:31 PM, Jason Wang<jasowang@redhat.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On 2018年03月20日 06:14, Jonathan Helman wrote: >>>>>>>>> Export the number of successful and failed hugetlb page >>>>>>>>> allocations via the virtio balloon driver. These 2 counts >>>>>>>>> come directly from the vm_events HTLB_BUDDY_PGALLOC and >>>>>>>>> HTLB_BUDDY_PGALLOC_FAIL. >>>>>>>>> >>>>>>>>> Signed-off-by: Jonathan Helman<jonathan.helman@oracle.com> >>>>>>>> Reviewed-by: Jason Wang<jasowang@redhat.com> >>>>>>> Thanks. >>>>>>> >>>>>>>>> --- >>>>>>>>> drivers/virtio/virtio_balloon.c | 6 ++++++ >>>>>>>>> include/uapi/linux/virtio_balloon.h | 4 +++- >>>>>>>>> 2 files changed, 9 insertions(+), 1 deletion(-) >>>>>>>>> >>>>>>>>> diff --git a/drivers/virtio/virtio_balloon.c >>>>>>>>> b/drivers/virtio/virtio_balloon.c >>>>>>>>> index dfe5684..6b237e3 100644 >>>>>>>>> --- a/drivers/virtio/virtio_balloon.c >>>>>>>>> +++ b/drivers/virtio/virtio_balloon.c >>>>>>>>> @@ -272,6 +272,12 @@ static unsigned int >>>>>>>>> update_balloon_stats(struct virtio_balloon *vb) >>>>>>>>> pages_to_bytes(events[PSWPOUT])); >>>>>>>>> update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, >>>>>>>>> events[PGMAJFAULT]); >>>>>>>>> update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, >>>>>>>>> events[PGFAULT]); >>>>>>>>> +#ifdef CONFIG_HUGETLB_PAGE >>>>>>>>> + update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGALLOC, >>>>>>>>> + events[HTLB_BUDDY_PGALLOC]); >>>>>>>>> + update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGFAIL, >>>>>>>>> + events[HTLB_BUDDY_PGALLOC_FAIL]); >>>>>>>>> +#endif >>>>>>>>> #endif >>>>>>>>> update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE, >>>>>>>>> pages_to_bytes(i.freeram)); >>>>>>>>> diff --git a/include/uapi/linux/virtio_balloon.h >>>>>>>>> b/include/uapi/linux/virtio_balloon.h >>>>>>>>> index 4e8b830..40297a3 100644 >>>>>>>>> --- a/include/uapi/linux/virtio_balloon.h >>>>>>>>> +++ b/include/uapi/linux/virtio_balloon.h >>>>>>>>> @@ -53,7 +53,9 @@ struct virtio_balloon_config { >>>>>>>>> #define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of >>>>>>>>> memory */ >>>>>>>>> #define VIRTIO_BALLOON_S_AVAIL 6 /* Available memory >>>>>>>>> as in /proc */ >>>>>>>>> #define VIRTIO_BALLOON_S_CACHES 7 /* Disk caches */ >>>>>>>>> -#define VIRTIO_BALLOON_S_NR 8 >>>>>>>>> +#define VIRTIO_BALLOON_S_HTLB_PGALLOC 8 /* Hugetlb page >>>>>>>>> allocations */ >>>>>>>>> +#define VIRTIO_BALLOON_S_HTLB_PGFAIL 9 /* Hugetlb page >>>>>>>>> allocation failures */ >>>>>>>>> +#define VIRTIO_BALLOON_S_NR 10 >>>>>>>>> /* >>>>>>>>> * Memory statistics structure. >>>>>>>> Not for this patch, but it looks to me that exporting such nr >>>>>>>> through uapi is fragile. >>>>>>> Sorry, can you explain what you mean here? >>>>>>> >>>>>>> Jon >>>>>> Spec said "Within an output buffer submitted to the statsq, the >>>>>> device MUST >>>>>> ignore entries with tag values that it does not recognize". So >>>>>> exporting >>>>>> VIRTIO_BALLOON_S_NR seems useless and device implementation can >>>>>> not depend >>>>>> on such number in uapi. >>>>>> >>>>>> Thanks >>>>> Suggestions? I don't like to break build for people ... >>>>> >>>> >>>> Didn't have a good idea. But maybe we should keep >>>> VIRTIO_BALLOON_S_NR unchanged, and add a comment here. >>>> >>>> Thanks >>> >>> I think Jason's comment is for a future patch. Didn't see this patch >>> get applied, so wondering if it could be. >>> >>> Thanks, >>> Jon >> >> Hi Jon: >> >> Have you tested new driver with old qemu? > > Yes, this testing scenario looks good. Thanks. > > Jon
Hi Jon:
I mean e.g compiling qemu with new linux headers. E.g current qemu has:
static const char *balloon_stat_names[] = { [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in", [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out", [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults", [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults", [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory", [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory", [VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory", [VIRTIO_BALLOON_S_CACHES] = "stat-disk-caches", [VIRTIO_BALLOON_S_NR] = NULL };
I'm afraid it will be broken if VIRTIO_BALLOON_S_NR is 10.
Thanks
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