Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Paolo Bonzini
On 4/13/22 16:51, Kevin Wolf wrote: So the idea is that we can do bdrv_graph_co_rdlock() in one thread and the corresponding bdrv_graph_co_rdunlock() in a different thread? Would the unlock somehow remember the original thread, or do you use the "sum is correct" argument and allow negative

Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Paolo Bonzini
On 4/13/22 18:29, Kevin Wolf wrote: A reader does not have to be a coroutine. AIO_WAIT_WHILE is not mandatory to allow it to finish, it helps to ensure progress in case some reader is waiting for something, but other than that is not necessary IMO. When it's outside of a coroutine, how would

Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Kevin Wolf
Am 13.04.2022 um 17:14 hat Emanuele Giuseppe Esposito geschrieben: > Am 13/04/2022 um 16:51 schrieb Kevin Wolf: > > Am 13.04.2022 um 15:43 hat Emanuele Giuseppe Esposito geschrieben: > >> So this is a more concrete and up-to-date header. > >> > >> Few things to notice: > >> - we have a list of

Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Emanuele Giuseppe Esposito
Am 13/04/2022 um 17:14 schrieb Emanuele Giuseppe Esposito: > > > Am 13/04/2022 um 16:51 schrieb Kevin Wolf: >> Am 13.04.2022 um 15:43 hat Emanuele Giuseppe Esposito geschrieben: >>> So this is a more concrete and up-to-date header. >>> >>> Few things to notice: >>> - we have a list of

Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Emanuele Giuseppe Esposito
Am 13/04/2022 um 16:51 schrieb Kevin Wolf: > Am 13.04.2022 um 15:43 hat Emanuele Giuseppe Esposito geschrieben: >> So this is a more concrete and up-to-date header. >> >> Few things to notice: >> - we have a list of AioContext. They are registered once an aiocontext >> is created, and deleted

Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Kevin Wolf
Am 13.04.2022 um 15:43 hat Emanuele Giuseppe Esposito geschrieben: > So this is a more concrete and up-to-date header. > > Few things to notice: > - we have a list of AioContext. They are registered once an aiocontext > is created, and deleted when it is destroyed. > This list is helpful because

Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept

2022-04-13 Thread Emanuele Giuseppe Esposito
So this is a more concrete and up-to-date header. Few things to notice: - we have a list of AioContext. They are registered once an aiocontext is created, and deleted when it is destroyed. This list is helpful because each aiocontext can only modify its own number of readers, avoiding unnecessary

[PATCH] block/rbd: support driver-specific reopen

2022-04-13 Thread Raphael Pour
This patch completes the reopen functionality for an attached RBD where altered driver options can be passed to. This is necessary to move RBDs between ceph clusters without interrupting QEMU, where some ceph settings need to be adjusted. The reopen_prepare method early returns if no