Re: [Qemu-devel] [RFC PATCH V3 3/4] colo-compare: introduce packet comparison thread

[Zhang Chen]

On 04/28/2016 03:58 PM, Jason Wang wrote:
> On 04/18/2016 07:11 PM, Zhang Chen wrote:
> > if packets are same, we send primary packet and drop secondary
> > packet, otherwise notify COLO do checkpoint.
> >
> > Signed-off-by: Zhang Chen <address@hidden>
> > Signed-off-by: Li Zhijian <address@hidden>
> > Signed-off-by: Wen Congyang <address@hidden>
> > ---
> >   net/colo-compare.c | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   trace-events       |   2 +
> >   2 files changed, 128 insertions(+)
> >
> > diff --git a/net/colo-compare.c b/net/colo-compare.c
> > index dc57eac..4b5a2d4 100644
> > --- a/net/colo-compare.c
> > +++ b/net/colo-compare.c
> > @@ -26,6 +26,7 @@
> >   #include "qemu/jhash.h"
> >   #include "net/eth.h"
> >   
> > +#define DEBUG_TCP_COMPARE 1
> >   #define TYPE_COLO_COMPARE "colo-compare"
> >   #define COLO_COMPARE(obj) \
> >       OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
> > @@ -90,6 +91,13 @@ typedef struct CompareState {
> >       GQueue unprocessed_connections;
> >       /* proxy current hash size */
> >       uint32_t hashtable_size;
> > +
> > +    /* notify compare thread */
> > +    QemuEvent event;
> > +    /* compare thread, a thread for each NIC */
> > +    QemuThread thread;
> > +    int thread_status;
> > +
> >   } CompareState;
> >   
> >   typedef struct CompareClass {
> > @@ -132,6 +140,15 @@ enum {
> >       SECONDARY_IN,
> >   };
> >   
> > +enum {
> > +    /* compare thread isn't started */
> > +    COMPARE_THREAD_NONE,
> > +    /* compare thread is running */
> > +    COMPARE_THREAD_RUNNING,
> > +    /* compare thread exit */
> > +    COMPARE_THREAD_EXIT,
> > +};
> > +
> >   static void packet_destroy(void *opaque, void *user_data);
> >   static int compare_chr_send(CharDriverState *out,
> >                               const uint8_t *buf,
> > @@ -336,6 +353,94 @@ static void packet_destroy(void *opaque, void *user_data)
> >       g_slice_free(Packet, pkt);
> >   }
> >   
> > +static inline void colo_dump_packet(Packet *pkt)
> > +{
> > +    int i;
> > +    for (i = 0; i < pkt->size; i++) {
> > +        printf("%02x ", ((uint8_t *)pkt->data)[i]);
> > +    }
> > +    printf("\n");
> Can we use something like qemu_hexdump() here?

Thanks~~
I will change it to qemu_hexdump

> > +}
> > +
> > +/*
> > + * The IP packets sent by primary and secondary
> > + * will be compared in here
> > + * TODO support ip fragment, Out-Of-Order
> > + * return:    0  means packet same
> > + *            > 0 || < 0 means packet different
> > + */
> > +static int colo_packet_compare(Packet *ppkt, Packet *spkt)
> > +{
> > +    trace_colo_compare_with_int("ppkt size", ppkt->size);
> > +    trace_colo_compare_with_char("ppkt ip_src", inet_ntoa(ppkt->ip->ip_src));
> > +    trace_colo_compare_with_char("ppkt ip_dst", inet_ntoa(ppkt->ip->ip_dst));
> > +    trace_colo_compare_with_int("spkt size", spkt->size);
> > +    trace_colo_compare_with_char("spkt ip_src", inet_ntoa(spkt->ip->ip_src));
> > +    trace_colo_compare_with_char("spkt ip_dst", inet_ntoa(spkt->ip->ip_dst));
> Can we use a single tracepoint here instead?

Yes,fix in next.

> > +
> > +    if (ppkt->size == spkt->size) {
> > +        return memcmp(ppkt->data, spkt->data, spkt->size);
> > +    } else {
> > +        return -1;
> > +    }
> > +}
> > +
> > +static int colo_packet_compare_all(Packet *spkt, Packet *ppkt)
> > +{
> > +    trace_colo_compare_main("compare all");
> > +    return colo_packet_compare(ppkt, spkt);
> Why need this?

just temp name,will change in patch 4/4

> > +}
> > +
> > +/*
> > + * called from the compare thread on the primary
> > + * for compare connection
> > + */
> > +static void colo_compare_connection(void *opaque, void *user_data)
> > +{
> > +    Connection *conn = opaque;
> > +    Packet *pkt = NULL;
> > +    GList *result = NULL;
> > +    int ret;
> > +
> > +    qemu_mutex_lock(&conn->list_lock);
> > +    while (!g_queue_is_empty(&conn->primary_list) &&
> > +           !g_queue_is_empty(&conn->secondary_list)) {
> > +        pkt = g_queue_pop_head(&conn->primary_list);
> > +        result = g_queue_find_custom(&conn->secondary_list,
> > +                              pkt, (GCompareFunc)colo_packet_compare_all);
> > +
> > +        if (result) {
> > +            ret = compare_chr_send(pkt->s->chr_out, pkt->data, pkt->size);
> > +            if (ret < 0) {
> > +                error_report("colo_send_primary_packet failed");
> > +            }
> > +            trace_colo_compare_main("packet same and release packet");
> > +            g_queue_remove(&conn->secondary_list, result->data);
> > +        } else {
> > +            trace_colo_compare_main("packet different");
> > +            g_queue_push_head(&conn->primary_list, pkt);
> Is this possible that the packet from secondary has not been arrived on
> time? If yes, do we still need to notify the checkpoint here?

Yes,the packet of secondary may not arrived.
we will hold primary packet to next periodic checkpoint
to flush it. and more, I consider to set a timer
to flush timeout(200ms???) packet like Dave's branch.


Thanks
zhangchen

> > +            /* TODO: colo_notify_checkpoint();*/
> > +            break;
> > +        }
> > +    }
> > +    qemu_mutex_unlock(&conn->list_lock);
> > +}
> > +
> > +static void *colo_compare_thread(void *opaque)
> > +{
> > +    CompareState *s = opaque;
> > +
> > +    while (s->thread_status == COMPARE_THREAD_RUNNING) {
> > +        qemu_event_wait(&s->event);
> > +        qemu_event_reset(&s->event);
> > +        qemu_mutex_lock(&s->conn_list_lock);
> > +        g_queue_foreach(&s->conn_list, colo_compare_connection, NULL);
> > +        qemu_mutex_unlock(&s->conn_list_lock);
> > +    }
> > +
> > +    return NULL;
> > +}
> > +
> >   static int compare_chr_send(CharDriverState *out,
> >                               const uint8_t *buf,
> >                               uint32_t size)
> > @@ -440,6 +545,8 @@ static void compare_pri_chr_in(void *opaque, const uint8_t 
> > *buf, int size)
> >           if (packet_enqueue(s, PRIMARY_IN)) {
> >               trace_colo_compare_main("primary: unsupported packet in");
> >               compare_chr_send(s->chr_out, s->pri_rs.buf, s->pri_rs.packet_len);
> > +        } else {
> > +            qemu_event_set(&s->event);
> >           }
> >       } else if (ret == -1) {
> >           qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
> > @@ -461,6 +568,8 @@ static void compare_sec_chr_in(void *opaque, const uint8_t 
> > *buf, int size)
> >               trace_colo_compare_main("secondary: unsupported packet in");
> >               /* should we send sec arp pkt? */
> >               compare_chr_send(s->chr_out, s->sec_rs.buf, s->sec_rs.packet_len);
> > +        } else {
> > +            qemu_event_set(&s->event);
> >           }
> >       } else if (ret == -1) {
> >           qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
> > @@ -519,6 +628,8 @@ static void compare_set_outdev(Object *obj, const char 
> > *value, Error **errp)
> >   static void colo_compare_complete(UserCreatable *uc, Error **errp)
> >   {
> >       CompareState *s = COLO_COMPARE(uc);
> > +    char thread_name[64];
> > +    static int compare_id;
> >   
> >       if (!s->pri_indev || !s->sec_indev || !s->outdev) {
> >           error_setg(errp, "colo compare needs 'primary_in' ,"
> > @@ -564,6 +675,7 @@ static void colo_compare_complete(UserCreatable *uc, Error 
> > **errp)
> >       QTAILQ_INSERT_TAIL(&net_compares, s, next);
> >   
> >       g_queue_init(&s->conn_list);
> > +    qemu_event_init(&s->event, false);
> >       qemu_mutex_init(&s->conn_list_lock);
> >       s->hashtable_size = 0;
> >   
> > @@ -572,6 +684,13 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
> >                                                         g_free,
> >                                                         connection_destroy);
> >   
> > +    s->thread_status = COMPARE_THREAD_RUNNING;
> > +    sprintf(thread_name, "compare %d", compare_id);
> > +    qemu_thread_create(&s->thread, thread_name,
> > +                       colo_compare_thread, s,
> > +                       QEMU_THREAD_JOINABLE);
> > +    compare_id++;
> > +
> >       return;
> >   }
> >   
> > @@ -607,6 +726,13 @@ static void colo_compare_class_finalize(ObjectClass *oc, void *data)
> >           QTAILQ_REMOVE(&net_compares, s, next);
> >       }
> >       qemu_mutex_destroy(&s->conn_list_lock);
> > +
> > +    if (s->thread.thread) {
> > +        s->thread_status = COMPARE_THREAD_EXIT;
> > +        qemu_event_set(&s->event);
> > +        qemu_thread_join(&s->thread);
> > +    }
> > +    qemu_event_destroy(&s->event);
> >   }
> >   
> >   static void colo_compare_init(Object *obj)
> > diff --git a/trace-events b/trace-events
> > index 8862288..978c47f 100644
> > --- a/trace-events
> > +++ b/trace-events
> > @@ -1919,3 +1919,5 @@ aspeed_vic_write(uint64_t offset, unsigned size, uint32_t data) 
> > "To 0x%" PRIx64
> >   
> >   # net/colo-compare.c
> >   colo_compare_main(const char *chr) "chr: %s"
> > +colo_compare_with_int(const char *sta, int size) ": %s = %d"
> > +colo_compare_with_char(const char *sta, const char *stb) ": %s = %s"
>
>
> .

--
Thanks
zhangchen