search for: busy_wait

...-- tools/virtio/ringtest/main.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h index 593a328..301d59b 100644 --- a/tools/virtio/ringtest/main.h +++ b/tools/virtio/ringtest/main.h @@ -111,7 +111,7 @@ static inline void busy_wait(void) } #if defined(__x86_64__) || defined(__i386__) -#define smp_mb() asm volatile("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") +#define smp_mb() asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc") #else /* *...

...-- tools/virtio/ringtest/main.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h index 593a328..301d59b 100644 --- a/tools/virtio/ringtest/main.h +++ b/tools/virtio/ringtest/main.h @@ -111,7 +111,7 @@ static inline void busy_wait(void) } #if defined(__x86_64__) || defined(__i386__) -#define smp_mb() asm volatile("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") +#define smp_mb() asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc") #else /* *...

...ei Wang wrote: > - if (!virtqueue_indirect_desc_table_add(vq, desc, num)) { > + if (!virtqueue_indirect_desc_table_add(vq, desc, *num)) { > virtqueue_kick(vq); > - wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > - vb->balloon_page_chunk.chunk_num = 0; > + if (busy_wait) > + while (!virtqueue_get_buf(vq, &len) && > + !virtqueue_is_broken(vq)) > + cpu_relax(); > + else > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); This is something I didn't previously notice. As you always keep a single buffer in fl...

...ei Wang wrote: > - if (!virtqueue_indirect_desc_table_add(vq, desc, num)) { > + if (!virtqueue_indirect_desc_table_add(vq, desc, *num)) { > virtqueue_kick(vq); > - wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > - vb->balloon_page_chunk.chunk_num = 0; > + if (busy_wait) > + while (!virtqueue_get_buf(vq, &len) && > + !virtqueue_is_broken(vq)) > + cpu_relax(); > + else > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); This is something I didn't previously notice. As you always keep a single buffer in fl...

..._balloon *vb) >> +{ >> + int i; >> + >> + for (i = 0; i < vb->nr_page_bmap; i++) >> + memset(vb->page_bitmap[i], 0, PAGE_BMAP_SIZE); >> +} >> + >> +static void send_resp_data(struct virtio_balloon *vb, struct virtqueue *vq, >> + bool busy_wait) >> +{ >> + struct scatterlist sg[2]; >> + struct virtio_balloon_resp_hdr *hdr = &vb->resp_hdr; >> unsigned int len; >> >> - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); >> + len = hdr->data_len = vb->resp_...

...olatile("" ::: "memory") + +/* Is there a portable way to do this? */ +#if defined(__x86_64__) || defined(__i386__) +#define cpu_relax() asm ("rep; nop" ::: "memory") +#else +#define cpu_relax() assert(0) +#endif + +extern bool do_relax; + +static inline void busy_wait(void) +{ + if (do_relax) + cpu_relax(); + else + /* prevent compiler from removing busy loops */ + barrier(); +} + +/* + * Not using __ATOMIC_SEQ_CST since gcc docs say they are only synchronized + * with other __ATOMIC_SEQ_CST calls. + */ +#define smp_mb() __sync_synchronize() + +/* + * This a...

...olatile("" ::: "memory") + +/* Is there a portable way to do this? */ +#if defined(__x86_64__) || defined(__i386__) +#define cpu_relax() asm ("rep; nop" ::: "memory") +#else +#define cpu_relax() assert(0) +#endif + +extern bool do_relax; + +static inline void busy_wait(void) +{ + if (do_relax) + cpu_relax(); + else + /* prevent compiler from removing busy loops */ + barrier(); +} + +/* + * Not using __ATOMIC_SEQ_CST since gcc docs say they are only synchronized + * with other __ATOMIC_SEQ_CST calls. + */ +#define smp_mb() __sync_synchronize() + +/* + * This a...

...void clear_page_bitmap(struct virtio_balloon *vb) > +{ > + int i; > + > + for (i = 0; i < vb->nr_page_bmap; i++) > + memset(vb->page_bitmap[i], 0, PAGE_BMAP_SIZE); > +} > + > +static void send_resp_data(struct virtio_balloon *vb, struct virtqueue *vq, > + bool busy_wait) > +{ > + struct scatterlist sg[2]; > + struct virtio_balloon_resp_hdr *hdr = &vb->resp_hdr; > unsigned int len; > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > + len = hdr->data_len = vb->resp_pos * sizeof(__le64); > + s...

...void clear_page_bitmap(struct virtio_balloon *vb) > +{ > + int i; > + > + for (i = 0; i < vb->nr_page_bmap; i++) > + memset(vb->page_bitmap[i], 0, PAGE_BMAP_SIZE); > +} > + > +static void send_resp_data(struct virtio_balloon *vb, struct virtqueue *vq, > + bool busy_wait) > +{ > + struct scatterlist sg[2]; > + struct virtio_balloon_resp_hdr *hdr = &vb->resp_hdr; > unsigned int len; > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > + len = hdr->data_len = vb->resp_pos * sizeof(__le64); > + s...

...free(vb->page_bitmap[i]); +} + +static void clear_page_bitmap(struct virtio_balloon *vb) +{ + int i; + + for (i = 0; i < vb->nr_page_bmap; i++) + memset(vb->page_bitmap[i], 0, BALLOON_BMAP_SIZE); +} + +static void send_resp_data(struct virtio_balloon *vb, struct virtqueue *vq, + bool busy_wait) +{ + struct scatterlist sg[2]; + struct virtio_balloon_resp_hdr *hdr = vb->resp_hdr; unsigned int len; - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); + len = hdr->data_len = vb->resp_pos * sizeof(__le64); + sg_init_table(sg, 2); + sg_set_buf(&sg[0],...

...kfree(vb->page_bitmap[i]); +} + +static void clear_page_bitmap(struct virtio_balloon *vb) +{ + int i; + + for (i = 0; i < vb->nr_page_bmap; i++) + memset(vb->page_bitmap[i], 0, PAGE_BMAP_SIZE); +} + +static void send_resp_data(struct virtio_balloon *vb, struct virtqueue *vq, + bool busy_wait) +{ + struct scatterlist sg[2]; + struct virtio_balloon_resp_hdr *hdr = &vb->resp_hdr; unsigned int len; - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); + len = hdr->data_len = vb->resp_pos * sizeof(__le64); + sg_init_table(sg, 2); + sg_set_buf(&s...

...>> +{ >> + int i; >> + >> + for (i = 0; i < vb->page_bmaps; i++) >> + memset(vb->page_bmap[i], 0, PAGE_BMAP_SIZE); >> +} >> + >> +static void send_page_chunks(struct virtio_balloon *vb, struct virtqueue *vq, >> + int type, bool busy_wait) > busy_wait seems unused. pls drop. It will be used in the other patch (the 5th patch) for sending unused pages. Probably I can add it from that patch. > >> { >> struct scatterlist sg; >> + struct virtio_balloon_page_chunk_hdr *hdr; >> + void *buf; >>...

...page_bmap(struct virtio_balloon *vb) > +{ > + int i; > + > + for (i = 0; i < vb->page_bmaps; i++) > + memset(vb->page_bmap[i], 0, PAGE_BMAP_SIZE); > +} > + > +static void send_page_chunks(struct virtio_balloon *vb, struct virtqueue *vq, > + int type, bool busy_wait) busy_wait seems unused. pls drop. > { > struct scatterlist sg; > + struct virtio_balloon_page_chunk_hdr *hdr; > + void *buf; > unsigned int len; > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > + switch (type) { > + case PAGE_...

...page_bmap(struct virtio_balloon *vb) > +{ > + int i; > + > + for (i = 0; i < vb->page_bmaps; i++) > + memset(vb->page_bmap[i], 0, PAGE_BMAP_SIZE); > +} > + > +static void send_page_chunks(struct virtio_balloon *vb, struct virtqueue *vq, > + int type, bool busy_wait) busy_wait seems unused. pls drop. > { > struct scatterlist sg; > + struct virtio_balloon_page_chunk_hdr *hdr; > + void *buf; > unsigned int len; > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > + switch (type) { > + case PAGE_...

Take over this work from Liang. This patch series implements two optimizations: 1) transfer pages in chuncks between the guest and host; 1) transfer the guest unused pages to the host so that they can be skipped to migrate in live migration. Please check patch 0003 for more details about optimization 1). For an idle guest with 8GB RAM, optimization 2) can help shorten the total live migration

Take over this work from Liang. This patch series implements two optimizations: 1) transfer pages in chuncks between the guest and host; 1) transfer the guest unused pages to the host so that they can be skipped to migrate in live migration. Please check patch 0003 for more details about optimization 1). For an idle guest with 8GB RAM, optimization 2) can help shorten the total live migration

...h | 57 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h index 5706e07..593a328 100644 --- a/tools/virtio/ringtest/main.h +++ b/tools/virtio/ringtest/main.h @@ -134,4 +134,61 @@ static inline void busy_wait(void) barrier(); \ } while (0) +#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__) +#define smp_wmb() barrier() +#else +#define smp_wmb() smp_release() +#endif + +#ifdef __alpha__ +#define smp_read_barrier_depends() smp_acquire() +#else +#define smp_read_barrier_depends() do...

...2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h > index 593a328..301d59b 100644 > --- a/tools/virtio/ringtest/main.h > +++ b/tools/virtio/ringtest/main.h > @@ -111,7 +111,7 @@ static inline void busy_wait(void) > } > > #if defined(__x86_64__) || defined(__i386__) > -#define smp_mb() asm volatile("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") Just wonder did "rsp" work for __i386__ ? Thanks > +#define smp_mb() asm volatile(&quo...

...me as the pvticketlock, using the same lock_spinning and unlock_lock hooks. The x86-specific codepath can use bit 1 in the ->wait byte as "I have halted, please kick me". value = _QSPINLOCK_WAITING; i = 0; do cpu_relax(); while (ACCESS_ONCE(slock->lock) && i++ < BUSY_WAIT); if (ACCESS_ONCE(slock->lock)) { value |= _QSPINLOCK_HALTED; xchg(&slock->wait, value >> 8); if (ACCESS_ONCE(slock->lock)) { ... call lock_spinning hook ... } } /* * Set the lock bit & clear the halted+waiting bits */ if (cmpxchg(&slock->lock_wait,...

...+ if (!virtqueue_indirect_desc_table_add(vq, desc, *num)) { >>>>>> virtqueue_kick(vq); >>>>>> - wait_event(vb->acked, virtqueue_get_buf(vq, &len)); >>>>>> - vb->balloon_page_chunk.chunk_num = 0; >>>>>> + if (busy_wait) >>>>>> + while (!virtqueue_get_buf(vq, &len) && >>>>>> + !virtqueue_is_broken(vq)) >>>>>> + cpu_relax(); >>>>>> + else >>>>>> + wait_event(vb->acked, virtqueue_get_buf(vq, &amp...