Re: [Qemu-block] [RFC v5] RBD: Add support readv,writev for rbd

[Jaze Lee]

No yet. I just test on one qemu-kvm vm. It works fine.
The performance may need more time.
Any one can test on this patch if you do fast....

2017-02-16 20:07 GMT+08:00 Tiger Hu <address@hidden>:
> Tianqing,
>
> Do we have any performance data for this patch? Thanks.
>
> Tiger
>> 在 2017年2月16日，下午5:address@hidden 写道：
>>
>> From: tianqing <address@hidden>
>>
>> Rbd can do readv and writev directly, so wo do not need to transform
>> iov to buf or vice versa any more.
>>
>> Signed-off-by: tianqing <address@hidden>
>> ---
>> block/rbd.c | 49 ++++++++++++++++++++++++++++++++++++++++++-------
>> 1 file changed, 42 insertions(+), 7 deletions(-)
>>
>> diff --git a/block/rbd.c b/block/rbd.c
>> index a57b3e3..75ae1d6 100644
>> --- a/block/rbd.c
>> +++ b/block/rbd.c
>> @@ -47,7 +47,7 @@
>>  */
>>
>> /* rbd_aio_discard added in 0.1.2 */
>> -#if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 2)
>> +#if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(12, 0, 0)
>> #define LIBRBD_SUPPORTS_DISCARD
>> #else
>> #undef LIBRBD_SUPPORTS_DISCARD
>> @@ -73,7 +73,12 @@ typedef struct RBDAIOCB {
>>     BlockAIOCB common;
>>     int64_t ret;
>>     QEMUIOVector *qiov;
>> +/* Note:
>> + * The LIBRBD_SUPPORTS_IOVEC is defined in librbd.h.
>> + */
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>     char *bounce;
>> +#endif
>>     RBDAIOCmd cmd;
>>     int error;
>>     struct BDRVRBDState *s;
>> @@ -83,7 +88,9 @@ typedef struct RADOSCB {
>>     RBDAIOCB *acb;
>>     struct BDRVRBDState *s;
>>     int64_t size;
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>     char *buf;
>> +#endif
>>     int64_t ret;
>> } RADOSCB;
>>
>> @@ -426,11 +433,21 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb)
>>         }
>>     } else {
>>         if (r < 0) {
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>             memset(rcb->buf, 0, rcb->size);
>> +#else
>> +            iov_memset(acb->qiov->iov, acb->qiov->niov, 0, 0, 
>> acb->qiov->size);
>> +#endif
>>             acb->ret = r;
>>             acb->error = 1;
>>         } else if (r < rcb->size) {
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>             memset(rcb->buf + r, 0, rcb->size - r);
>> +#else
>> +            iov_memset(acb->qiov->iov, acb->qiov->niov,
>> +                       r, 0, acb->qiov->size - r);
>> +#endif
>> +
>>             if (!acb->error) {
>>                 acb->ret = rcb->size;
>>             }
>> @@ -441,10 +458,12 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb)
>>
>>     g_free(rcb);
>>
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>     if (acb->cmd == RBD_AIO_READ) {
>>         qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
>>     }
>>     qemu_vfree(acb->bounce);
>> +#endif
>>     acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
>>
>>     qemu_aio_unref(acb);
>> @@ -655,8 +674,10 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
>>     RBDAIOCB *acb;
>>     RADOSCB *rcb = NULL;
>>     rbd_completion_t c;
>> -    char *buf;
>>     int r;
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>> +    char *buf = NULL;
>> +#endif
>>
>>     BDRVRBDState *s = bs->opaque;
>>
>> @@ -664,6 +685,8 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
>>     acb->cmd = cmd;
>>     acb->qiov = qiov;
>>     assert(!qiov || qiov->size == size);
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>> +
>>     if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
>>         acb->bounce = NULL;
>>     } else {
>> @@ -672,19 +695,21 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
>>             goto failed;
>>         }
>>     }
>> -    acb->ret = 0;
>> -    acb->error = 0;
>> -    acb->s = s;
>> -
>>     if (cmd == RBD_AIO_WRITE) {
>>         qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
>>     }
>> -
>>     buf = acb->bounce;
>> +#endif
>> +    acb->ret = 0;
>> +    acb->error = 0;
>> +    acb->s = s;
>>
>>     rcb = g_new(RADOSCB, 1);
>> +
>>     rcb->acb = acb;
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>     rcb->buf = buf;
>> +#endif
>>     rcb->s = acb->s;
>>     rcb->size = size;
>>     r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, 
>> &c);
>> @@ -694,10 +719,18 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
>>
>>     switch (cmd) {
>>     case RBD_AIO_WRITE:
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>         r = rbd_aio_write(s->image, off, size, buf, c);
>> +#else
>> +        r = rbd_aio_writev(s->image, qiov->iov, qiov->niov, off, c);
>> +#endif
>>         break;
>>     case RBD_AIO_READ:
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>         r = rbd_aio_read(s->image, off, size, buf, c);
>> +#else
>> +        r = rbd_aio_readv(s->image, qiov->iov, qiov->niov, off, c);
>> +#endif
>>         break;
>>     case RBD_AIO_DISCARD:
>>         r = rbd_aio_discard_wrapper(s->image, off, size, c);
>> @@ -719,7 +752,9 @@ failed_completion:
>>     rbd_aio_release(c);
>> failed:
>>     g_free(rcb);
>> +#ifndef LIBRBD_SUPPORTS_IOVEC
>>     qemu_vfree(acb->bounce);
>> +#endif
>>     qemu_aio_unref(acb);
>>     return NULL;
>> }
>> --
>> 2.10.2
>>
>> --
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>



-- 
谦谦君子