Re: [Qemu-devel] [Qemu-block] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex
On Thu 25 May 2017 06:32:16 PM CEST, Paolo Bonzini wrote: > Another possibility is to use tg->lock, which we're holding anyway in > both schedule_next_request and throttle_group_co_io_limits_intercept. > This would require open-coding the CoQueue however, so I've chosen this > alternative. > > Reviewed-by: Stefan Hajnoczi > Signed-off-by: Paolo Bonzini Reviewed-by: Alberto Garcia Berto
Re: [Qemu-devel] [Qemu-block] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex
On Thu 18 May 2017 02:08:32 PM CEST, Paolo Bonzini wrote: >> Does io_limits_disabled need locking too? > > It uses atomic access since patch 3. Ah, I overlooked that one, sorry! Berto
Re: [Qemu-devel] [Qemu-block] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex
On 18/05/2017 14:06, Alberto Garcia wrote:
> On Thu 11 May 2017 04:41:59 PM CEST, Paolo Bonzini wrote:
>
>> --- a/include/sysemu/block-backend.h
>> +++ b/include/sysemu/block-backend.h
>> @@ -72,11 +72,8 @@ typedef struct BlockDevOps {
>> * fields that must be public. This is in particular for QLIST_ENTRY() and
>> * friends so that BlockBackends can be kept in lists outside
>> block-backend.c */
>> typedef struct BlockBackendPublic {
>> -/* I/O throttling has its own locking, but also some fields are
>> - * protected by the AioContext lock.
>> - */
>> -
>> -/* Protected by AioContext lock. */
>> +/* throttled_reqs_lock protects the CoQueues for throttled requests. */
>> +CoMutex throttled_reqs_lock;
>> CoQueue throttled_reqs[2];
>>
>> /* Nonzero if the I/O limits are currently being ignored; generally
>> * it is zero. */
>> unsigned int io_limits_disabled;
>
> Does io_limits_disabled need locking too?
It uses atomic access since patch 3.
Paolo
Re: [Qemu-devel] [Qemu-block] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex
On Thu 11 May 2017 04:41:59 PM CEST, Paolo Bonzini wrote:
> --- a/include/sysemu/block-backend.h
> +++ b/include/sysemu/block-backend.h
> @@ -72,11 +72,8 @@ typedef struct BlockDevOps {
> * fields that must be public. This is in particular for QLIST_ENTRY() and
> * friends so that BlockBackends can be kept in lists outside
> block-backend.c */
> typedef struct BlockBackendPublic {
> -/* I/O throttling has its own locking, but also some fields are
> - * protected by the AioContext lock.
> - */
> -
> -/* Protected by AioContext lock. */
> +/* throttled_reqs_lock protects the CoQueues for throttled requests. */
> +CoMutex throttled_reqs_lock;
> CoQueue throttled_reqs[2];
>
> /* Nonzero if the I/O limits are currently being ignored; generally
> * it is zero. */
> unsigned int io_limits_disabled;
Does io_limits_disabled need locking too?
Berto
