From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754192AbeDIVLb (ORCPT ); Mon, 9 Apr 2018 17:11:31 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:53584 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752422AbeDIVL1 (ORCPT ); Mon, 9 Apr 2018 17:11:27 -0400 Subject: Re: [virtio-dev] Re: [PATCH v2] virtio_balloon: export hugetlb page allocation counts To: Jason Wang , "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: Jonathan Helman Organization: Oracle Corporation Message-ID: Date: Mon, 9 Apr 2018 14:11:19 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <3f8a1b91-c5ba-8a24-72b8-02d884a67826@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8858 signatures=668698 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1804090213 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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