From: Paolo Bonzini <pbonzini@redhat.com>
To: Emanuele Giuseppe Esposito <eesposit@redhat.com>, qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Fam Zheng <fam@euphon.net>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-devel@nongnu.org, Hanna Reitz <hreitz@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
John Snow <jsnow@redhat.com>
Subject: Re: [PATCH 07/12] block/io.c: introduce bdrv_subtree_drained_{begin/end}_unlocked
Date: Wed, 19 Jan 2022 10:52:54 +0100 [thread overview]
Message-ID: <1bd90b22-c8c6-3201-e26e-17fdb305eb19@redhat.com> (raw)
In-Reply-To: <20220118162738.1366281-8-eesposit@redhat.com>
On 1/18/22 17:27, Emanuele Giuseppe Esposito wrote:
> Same as the locked version, but use BDRV_POLL_UNLOCKED
... We are going to add drains to all graph modifications, and they are
generally performed without the AioContext lock taken.
Paolo
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block/io.c | 50 +++++++++++++++++++++++++++++-----------
> include/block/block-io.h | 2 ++
> 2 files changed, 39 insertions(+), 13 deletions(-)
>
> diff --git a/block/io.c b/block/io.c
> index 5123b7b713..9d5167f64a 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -244,6 +244,7 @@ typedef struct {
> bool begin;
> bool recursive;
> bool poll;
> + bool unlock;
> BdrvChild *parent;
> bool ignore_bds_parents;
> int *drained_end_counter;
> @@ -334,7 +335,7 @@ static bool bdrv_drain_poll_top_level(BlockDriverState *bs, bool recursive,
>
> static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
> BdrvChild *parent, bool ignore_bds_parents,
> - bool poll);
> + bool poll, bool unlock);
> static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
> BdrvChild *parent, bool ignore_bds_parents,
> int *drained_end_counter);
> @@ -352,7 +353,8 @@ static void bdrv_co_drain_bh_cb(void *opaque)
> if (data->begin) {
> assert(!data->drained_end_counter);
> bdrv_do_drained_begin(bs, data->recursive, data->parent,
> - data->ignore_bds_parents, data->poll);
> + data->ignore_bds_parents, data->poll,
> + data->unlock);
> } else {
> assert(!data->poll);
> bdrv_do_drained_end(bs, data->recursive, data->parent,
> @@ -374,6 +376,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
> BdrvChild *parent,
> bool ignore_bds_parents,
> bool poll,
> + bool unlock,
> int *drained_end_counter)
> {
> BdrvCoDrainData data;
> @@ -394,6 +397,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
> .parent = parent,
> .ignore_bds_parents = ignore_bds_parents,
> .poll = poll,
> + .unlock = unlock,
> .drained_end_counter = drained_end_counter,
> };
>
> @@ -441,13 +445,13 @@ static void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
>
> static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
> BdrvChild *parent, bool ignore_bds_parents,
> - bool poll)
> + bool poll, bool unlock)
> {
> BdrvChild *child, *next;
>
> if (qemu_in_coroutine()) {
> bdrv_co_yield_to_drain(bs, true, recursive, parent, ignore_bds_parents,
> - poll, NULL);
> + poll, unlock, NULL);
> return;
> }
>
> @@ -458,7 +462,7 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
> bs->recursive_quiesce_counter++;
> QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
> bdrv_do_drained_begin(child->bs, true, child, ignore_bds_parents,
> - false);
> + false, false);
> }
> }
>
> @@ -473,23 +477,35 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
> */
> if (poll) {
> assert(!ignore_bds_parents);
> - BDRV_POLL_WHILE(bs, bdrv_drain_poll_top_level(bs, recursive, parent));
> + if (unlock) {
> + BDRV_POLL_WHILE_UNLOCKED(bs,
> + bdrv_drain_poll_top_level(bs, recursive,
> + parent));
> + } else {
> + BDRV_POLL_WHILE(bs,
> + bdrv_drain_poll_top_level(bs, recursive, parent));
> + }
> }
> }
>
> void bdrv_drained_begin(BlockDriverState *bs)
> {
> - bdrv_do_drained_begin(bs, false, NULL, false, true);
> + bdrv_do_drained_begin(bs, false, NULL, false, true, false);
> }
>
> void bdrv_subtree_drained_begin(BlockDriverState *bs)
> {
> - bdrv_do_drained_begin(bs, true, NULL, false, true);
> + bdrv_do_drained_begin(bs, true, NULL, false, true, false);
> +}
> +
> +void bdrv_subtree_drained_begin_unlocked(BlockDriverState *bs)
> +{
> + bdrv_do_drained_begin(bs, true, NULL, false, true, true);
> }
>
> void bdrv_drained_begin_no_poll(BlockDriverState *bs)
> {
> - bdrv_do_drained_begin(bs, false, NULL, false, false);
> + bdrv_do_drained_begin(bs, false, NULL, false, false, false);
> }
>
> /**
> @@ -517,7 +533,7 @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
>
> if (qemu_in_coroutine()) {
> bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_parents,
> - false, drained_end_counter);
> + false, false, drained_end_counter);
> return;
> }
> assert(bs->quiesce_counter > 0);
> @@ -561,12 +577,19 @@ void bdrv_subtree_drained_end(BlockDriverState *bs)
> BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0);
> }
>
> +void bdrv_subtree_drained_end_unlocked(BlockDriverState *bs)
> +{
> + int drained_end_counter = 0;
> + bdrv_do_drained_end(bs, true, NULL, false, &drained_end_counter);
> + BDRV_POLL_WHILE_UNLOCKED(bs, qatomic_read(&drained_end_counter) > 0);
> +}
> +
> void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
> {
> int i;
>
> for (i = 0; i < new_parent->recursive_quiesce_counter; i++) {
> - bdrv_do_drained_begin(child->bs, true, child, false, true);
> + bdrv_do_drained_begin(child->bs, true, child, false, true, false);
> }
> }
>
> @@ -651,7 +674,8 @@ void bdrv_drain_all_begin(void)
> assert(qemu_in_main_thread());
>
> if (qemu_in_coroutine()) {
> - bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL);
> + bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, false,
> + NULL);
> return;
> }
>
> @@ -676,7 +700,7 @@ void bdrv_drain_all_begin(void)
> AioContext *aio_context = bdrv_get_aio_context(bs);
>
> aio_context_acquire(aio_context);
> - bdrv_do_drained_begin(bs, false, NULL, true, false);
> + bdrv_do_drained_begin(bs, false, NULL, true, false, false);
> aio_context_release(aio_context);
> }
>
> diff --git a/include/block/block-io.h b/include/block/block-io.h
> index 34a991649c..a329ae24c1 100644
> --- a/include/block/block-io.h
> +++ b/include/block/block-io.h
> @@ -253,6 +253,7 @@ void bdrv_drained_begin_no_poll(BlockDriverState *bs);
> * exclusive access to all child nodes as well.
> */
> void bdrv_subtree_drained_begin(BlockDriverState *bs);
> +void bdrv_subtree_drained_begin_unlocked(BlockDriverState *bs);
>
> /**
> * bdrv_drained_end:
> @@ -285,6 +286,7 @@ void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter);
> * End a quiescent section started by bdrv_subtree_drained_begin().
> */
> void bdrv_subtree_drained_end(BlockDriverState *bs);
> +void bdrv_subtree_drained_end_unlocked(BlockDriverState *bs);
>
> bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
> uint32_t granularity, Error **errp);
next prev parent reply other threads:[~2022-01-19 10:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-18 16:27 [PATCH 00/12] Removal of Aiocontext lock through drains: protect bdrv_replace_child_noperm Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 01/12] introduce BDRV_POLL_WHILE_UNLOCKED Emanuele Giuseppe Esposito
2022-01-26 10:49 ` Stefan Hajnoczi
2022-02-03 13:57 ` Emanuele Giuseppe Esposito
2022-02-04 12:13 ` Paolo Bonzini
2022-01-18 16:27 ` [PATCH 02/12] block/io.c: make bdrv_do_drained_begin_quiesce static and introduce bdrv_drained_begin_no_poll Emanuele Giuseppe Esposito
2022-01-19 9:11 ` Paolo Bonzini
2022-01-18 16:27 ` [PATCH 03/12] block.c: bdrv_replace_child_noperm: first remove the child, and then call ->detach() Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 04/12] block.c: bdrv_replace_child_noperm: first call ->attach(), and then add child Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 05/12] test-bdrv-drain.c: adapt test to the coming subtree drains Emanuele Giuseppe Esposito
2022-01-19 9:18 ` Paolo Bonzini
2022-02-03 11:41 ` Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 06/12] test-bdrv-drain.c: remove test_detach_by_parent_cb() Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 07/12] block/io.c: introduce bdrv_subtree_drained_{begin/end}_unlocked Emanuele Giuseppe Esposito
2022-01-19 9:52 ` Paolo Bonzini [this message]
2022-01-26 11:04 ` Stefan Hajnoczi
2022-01-18 16:27 ` [PATCH 08/12] reopen: add a transaction to drain_end nodes picked in bdrv_reopen_parse_file_or_backing Emanuele Giuseppe Esposito
2022-01-19 9:33 ` Paolo Bonzini
2022-01-26 11:16 ` Stefan Hajnoczi
2022-01-18 16:27 ` [PATCH 09/12] jobs: ensure sleep in job_sleep_ns is fully performed Emanuele Giuseppe Esposito
2022-01-26 11:21 ` Stefan Hajnoczi
2022-02-03 14:21 ` Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 10/12] block.c: add subtree_drains where needed Emanuele Giuseppe Esposito
2022-01-19 9:47 ` Paolo Bonzini
2022-02-03 13:13 ` Emanuele Giuseppe Esposito
2022-02-01 14:47 ` Vladimir Sementsov-Ogievskiy
2022-02-02 15:37 ` Emanuele Giuseppe Esposito
2022-02-02 17:38 ` Paolo Bonzini
2022-02-03 10:09 ` Emanuele Giuseppe Esposito
2022-02-04 9:49 ` Vladimir Sementsov-Ogievskiy
2022-02-04 13:30 ` Emanuele Giuseppe Esposito
2022-02-04 14:03 ` Vladimir Sementsov-Ogievskiy
2022-01-18 16:27 ` [PATCH 11/12] block/io.c: fully enable assert_bdrv_graph_writable Emanuele Giuseppe Esposito
2022-01-18 16:27 ` [PATCH 12/12] block.c: additional assert qemu in main tread Emanuele Giuseppe Esposito
2022-01-19 9:51 ` [PATCH 00/12] Removal of Aiocontext lock through drains: protect bdrv_replace_child_noperm Paolo Bonzini
2022-01-26 11:29 ` Stefan Hajnoczi
2022-01-27 13:46 ` Paolo Bonzini
2022-01-28 12:20 ` Emanuele Giuseppe Esposito
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