From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752745AbeDKDMM (ORCPT ); Tue, 10 Apr 2018 23:12:12 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:51154 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752381AbeDKDML (ORCPT ); Tue, 10 Apr 2018 23:12:11 -0400 Subject: Re: [virtio-dev] Re: [PATCH v2] virtio_balloon: export hugetlb page allocation counts To: Jonathan Helman , "Michael S. Tsirkin" Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, virtio-dev@lists.oasis-open.org, Mihai Carabas References: <1521497654-24807-1-git-send-email-jonathan.helman@oracle.com> <6ED6CAC9-FAD9-4A27-A9B1-C6EFC7627D68@oracle.com> <20180322050842-mutt-send-email-mst@kernel.org> <3f8a1b91-c5ba-8a24-72b8-02d884a67826@redhat.com> From: Jason Wang Message-ID: Date: Wed, 11 Apr 2018 11:12:04 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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  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 >>>>>> Reviewed-by: Jason Wang >>>>> 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? Thanks