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

[Alexandre DERUMIER <aderumier@odiso.com>]

>>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.... 

Hi, I would like to bench it with small 4k read/write.

On the ceph side,do we need this PR ? :
https://github.com/ceph/ceph/pull/13447


----- Mail original -----
De: "jazeltq" <jazeltq@gmail.com>
À: "Tiger Hu" <hufh2004@gmail.com>
Cc: "Josh Durgin" <jdurgin@redhat.com>, "Jeff Cody" <jcody@redhat.com>, "dillaman" <dillaman@redhat.com>, "Kevin Wolf" <kwolf@redhat.com>, mreitz@redhat.com, qemu-block@nongnu.org, "qemu-devel" <qemu-devel@nongnu.org>, "ceph-devel" <ceph-devel@vger.kernel.org>, "tianqing" <tianqing@unitedstack.com>
Envoyé: Jeudi 16 Février 2017 15:03:52
Objet: Re: [RFC v5] RBD: Add support readv,writev for rbd

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 <hufh2004@gmail.com>: 
> Tianqing, 
> 
> Do we have any performance data for this patch? Thanks. 
> 
> Tiger 
>> 在 2017年2月16日，下午5:00，jazeltq@gmail.com 写道： 
>> 
>> From: tianqing <tianqing@unitedstack.com> 
>> 
>> 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 <tianqing@unitedstack.com> 
>> --- 
>> 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 
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