From 12aa40822daf0ab13059b27b29a83ded43bae3bb Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 13 Jun 2018 20:18:12 +0200 Subject: block/mirror: Use CoQueue to wait on in-flight ops Attach a CoQueue to each in-flight operation so if we need to wait for any we can use it to wait instead of just blindly yielding and hoping for some operation to wake us. A later patch will use this infrastructure to allow requests accessing the same area of the virtual disk to specifically wait for each other. Signed-off-by: Max Reitz Reviewed-by: Fam Zheng Message-id: 20180613181823.13618-4-mreitz@redhat.com Signed-off-by: Max Reitz --- block/mirror.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) (limited to 'block') diff --git a/block/mirror.c b/block/mirror.c index dcc19ae..e2348b8 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -13,6 +13,7 @@ #include "qemu/osdep.h" #include "qemu/cutils.h" +#include "qemu/coroutine.h" #include "trace.h" #include "block/blockjob_int.h" #include "block/block_int.h" @@ -33,6 +34,8 @@ typedef struct MirrorBuffer { QSIMPLEQ_ENTRY(MirrorBuffer) next; } MirrorBuffer; +typedef struct MirrorOp MirrorOp; + typedef struct MirrorBlockJob { BlockJob common; BlockBackend *target; @@ -65,15 +68,15 @@ typedef struct MirrorBlockJob { unsigned long *in_flight_bitmap; int in_flight; int64_t bytes_in_flight; + QTAILQ_HEAD(MirrorOpList, MirrorOp) ops_in_flight; int ret; bool unmap; - bool waiting_for_io; int target_cluster_size; int max_iov; bool initial_zeroing_ongoing; } MirrorBlockJob; -typedef struct MirrorOp { +struct MirrorOp { MirrorBlockJob *s; QEMUIOVector qiov; int64_t offset; @@ -82,7 +85,11 @@ typedef struct MirrorOp { /* The pointee is set by mirror_co_read(), mirror_co_zero(), and * mirror_co_discard() before yielding for the first time */ int64_t *bytes_handled; -} MirrorOp; + + CoQueue waiting_requests; + + QTAILQ_ENTRY(MirrorOp) next; +}; typedef enum MirrorMethod { MIRROR_METHOD_COPY, @@ -123,7 +130,9 @@ static void coroutine_fn mirror_iteration_done(MirrorOp *op, int ret) chunk_num = op->offset / s->granularity; nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity); + bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); + QTAILQ_REMOVE(&s->ops_in_flight, op, next); if (ret >= 0) { if (s->cow_bitmap) { bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); @@ -133,11 +142,9 @@ static void coroutine_fn mirror_iteration_done(MirrorOp *op, int ret) } } qemu_iovec_destroy(&op->qiov); - g_free(op); - if (s->waiting_for_io) { - qemu_coroutine_enter(s->common.job.co); - } + qemu_co_queue_restart_all(&op->waiting_requests); + g_free(op); } static void coroutine_fn mirror_write_complete(MirrorOp *op, int ret) @@ -227,10 +234,11 @@ static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset, static inline void mirror_wait_for_io(MirrorBlockJob *s) { - assert(!s->waiting_for_io); - s->waiting_for_io = true; - qemu_coroutine_yield(); - s->waiting_for_io = false; + MirrorOp *op; + + op = QTAILQ_FIRST(&s->ops_in_flight); + assert(op); + qemu_co_queue_wait(&op->waiting_requests, NULL); } /* Perform a mirror copy operation. @@ -340,6 +348,7 @@ static unsigned mirror_perform(MirrorBlockJob *s, int64_t offset, .bytes = bytes, .bytes_handled = &bytes_handled, }; + qemu_co_queue_init(&op->waiting_requests); switch (mirror_method) { case MIRROR_METHOD_COPY: @@ -355,6 +364,7 @@ static unsigned mirror_perform(MirrorBlockJob *s, int64_t offset, abort(); } + QTAILQ_INSERT_TAIL(&s->ops_in_flight, op, next); qemu_coroutine_enter(co); /* At this point, ownership of op has been moved to the coroutine * and the object may already be freed */ @@ -1290,6 +1300,8 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs, } } + QTAILQ_INIT(&s->ops_in_flight); + trace_mirror_start(bs, s, opaque); job_start(&s->common.job); return; -- cgit v1.1