From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43512) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYERV-0004vH-7C for qemu-devel@nongnu.org; Tue, 23 Feb 2016 10:00:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aYERT-0002wZ-90 for qemu-devel@nongnu.org; Tue, 23 Feb 2016 10:00:01 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:40445 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYERS-0002uO-Tj for qemu-devel@nongnu.org; Tue, 23 Feb 2016 09:59:59 -0500 From: "Denis V. Lunev" Date: Tue, 23 Feb 2016 17:59:44 +0300 Message-Id: <1456239585-13324-2-git-send-email-den@openvz.org> In-Reply-To: <1456239585-13324-1-git-send-email-den@openvz.org> References: <1456239585-13324-1-git-send-email-den@openvz.org> Subject: [Qemu-devel] [PATCH 1/2] virtio-balloon: export all balloon statistics List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Igor Redko , "Michael S. Tsirkin" , qemu-devel@nongnu.org, "Denis V. Lunev" From: Igor Redko We are making experiments with different autoballooning strategies based on the guest behavior. Thus we need to experiment with different guest statistics. For now every counter change requires QEMU recompilation and dances with Libvirt. This patch introduces transport for unrecognized counters in virtio-balloon. This transport can be used for measuring benefits from using new balloon counters, before submitting any patches. Current alternative is 'guest-exec' transport which isn't made for such delicate matters and can influence test results. Originally all counters with tag >= VIRTIO_BALLOON_S_NR were ignored. Instead of this we keep first (VIRTIO_BALLOON_S_NR + 32) counters from the queue and pass unrecognized ones with the following names: 'x-stat-XXXX', where XXXX is a tag number in hex. Defined counters are reported with their regular names. Signed-off-by: Igor Redko Signed-off-by: Denis V. Lunev CC: Michael S. Tsirkin --- hw/virtio/virtio-balloon.c | 30 ++++++++++++++++++++++++------ include/hw/virtio/virtio-balloon.h | 3 ++- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index a382f43..1740293 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -66,8 +66,7 @@ static const char *balloon_stat_names[] = { */ static inline void reset_stats(VirtIOBalloon *dev) { - int i; - for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); + dev->stats_cnt = 0; } static bool balloon_stats_supported(const VirtIOBalloon *s) @@ -133,12 +132,20 @@ static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name, if (err) { goto out_end; } - for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) { - visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err); + for (i = 0; i < s->stats_cnt; i++) { + if (s->stats[i].tag < VIRTIO_BALLOON_S_NR) { + visit_type_uint64(v, balloon_stat_names[s->stats[i].tag], + &s->stats[i].val, &err); + } else { + gchar *str = g_strdup_printf("x-stat-%04x", s->stats[i].tag); + visit_type_uint64(v, str, &s->stats[i].val, &err); + g_free(str); + } if (err) { break; } } + error_propagate(errp, err); err = NULL; visit_end_struct(v, &err); @@ -273,10 +280,21 @@ static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) == sizeof(stat)) { uint16_t tag = virtio_tswap16(vdev, stat.tag); uint64_t val = virtio_tswap64(vdev, stat.val); + int i; offset += sizeof(stat); - if (tag < VIRTIO_BALLOON_S_NR) - s->stats[tag] = val; + for (i = 0; i < s->stats_cnt; i++) { + if (s->stats[i].tag == tag) { + break; + } + } + if (i < ARRAY_SIZE(s->stats)) { + s->stats[i].tag = tag; + s->stats[i].val = val; + if (s->stats_cnt <= i) { + s->stats_cnt = i + 1; + } + } } s->stats_vq_offset = offset; diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h index 35f62ac..5c8730e 100644 --- a/include/hw/virtio/virtio-balloon.h +++ b/include/hw/virtio/virtio-balloon.h @@ -36,7 +36,8 @@ typedef struct VirtIOBalloon { VirtQueue *ivq, *dvq, *svq; uint32_t num_pages; uint32_t actual; - uint64_t stats[VIRTIO_BALLOON_S_NR]; + VirtIOBalloonStatModern stats[VIRTIO_BALLOON_S_NR + 32]; + uint16_t stats_cnt; VirtQueueElement *stats_vq_elem; size_t stats_vq_offset; QEMUTimer *stats_timer; -- 2.1.4