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

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

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 <zhangchen.fnst@cn.fujitsu.com>
>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>>   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