Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-10 Thread Jens Axboe
On 02/10/2017 06:00 AM, Paolo Valente wrote: > >> Il giorno 08 feb 2017, alle ore 18:17, Omar Sandoval >> ha scritto: >> >> On Wed, Feb 08, 2017 at 11:39:24AM +0100, Paolo Valente wrote: >>> Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-10 Thread Jens Axboe
On 02/10/2017 06:00 AM, Paolo Valente wrote: > >> Il giorno 08 feb 2017, alle ore 18:17, Omar Sandoval >> ha scritto: >> >> On Wed, Feb 08, 2017 at 11:39:24AM +0100, Paolo Valente wrote: >>> Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval ha scritto: On Wed, Feb 08,

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-10 Thread Paolo Valente
> Il giorno 08 feb 2017, alle ore 18:17, Omar Sandoval ha > scritto: > > On Wed, Feb 08, 2017 at 11:39:24AM +0100, Paolo Valente wrote: >> >>> Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval >>> ha scritto: >>> >>> On Wed, Feb 08, 2017 at

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-10 Thread Paolo Valente
> Il giorno 08 feb 2017, alle ore 18:17, Omar Sandoval ha > scritto: > > On Wed, Feb 08, 2017 at 11:39:24AM +0100, Paolo Valente wrote: >> >>> Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval >>> ha scritto: >>> >>> On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote:

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Omar Sandoval
On Wed, Feb 08, 2017 at 11:39:24AM +0100, Paolo Valente wrote: > > > Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval > > ha scritto: > > > > On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote: > >> > >>> Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Omar Sandoval
On Wed, Feb 08, 2017 at 11:39:24AM +0100, Paolo Valente wrote: > > > Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval > > ha scritto: > > > > On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote: > >> > >>> Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval > >>> ha scritto:

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Paolo Valente
> Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval ha > scritto: > > On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote: >> Hi, >> this patch is meant to show that, if the body of the hook exit_icq is >> executed >> from inside that hook, and not as

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Paolo Valente
> Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval ha > scritto: > > On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote: >> Hi, >> this patch is meant to show that, if the body of the hook exit_icq is >> executed >> from inside that hook, and not as deferred work, then a

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Paolo Valente
> Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval ha > scritto: > > On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote: >> >>> Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval >>> ha scritto: >>> >>> On Tue, Feb 07, 2017 at

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Paolo Valente
> Il giorno 08 feb 2017, alle ore 11:33, Omar Sandoval ha > scritto: > > On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote: >> >>> Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval >>> ha scritto: >>> >>> On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote:

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Omar Sandoval
On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote: > > > Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval > > ha scritto: > > > > On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote: > >> Hi, > >> this patch is meant to show that, if the body of

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-08 Thread Omar Sandoval
On Wed, Feb 08, 2017 at 11:03:01AM +0100, Paolo Valente wrote: > > > Il giorno 07 feb 2017, alle ore 22:45, Omar Sandoval > > ha scritto: > > > > On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote: > >> Hi, > >> this patch is meant to show that, if the body of the hook exit_icq is

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-07 Thread Omar Sandoval
On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote: > Hi, > this patch is meant to show that, if the body of the hook exit_icq is > executed > from inside that hook, and not as deferred work, then a circular deadlock > occurs. > > It happens if, on a CPU > - the body of icq_exit

Re: [PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-07 Thread Omar Sandoval
On Tue, Feb 07, 2017 at 06:33:46PM +0100, Paolo Valente wrote: > Hi, > this patch is meant to show that, if the body of the hook exit_icq is > executed > from inside that hook, and not as deferred work, then a circular deadlock > occurs. > > It happens if, on a CPU > - the body of icq_exit

[PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-07 Thread Paolo Valente
Hi, this patch is meant to show that, if the body of the hook exit_icq is executed from inside that hook, and not as deferred work, then a circular deadlock occurs. It happens if, on a CPU - the body of icq_exit takes the scheduler lock, - it does so from inside the exit_icq hook, which is

[PATCH] bfq-mq: cause deadlock by executing exit_icq body immediately

2017-02-07 Thread Paolo Valente
Hi, this patch is meant to show that, if the body of the hook exit_icq is executed from inside that hook, and not as deferred work, then a circular deadlock occurs. It happens if, on a CPU - the body of icq_exit takes the scheduler lock, - it does so from inside the exit_icq hook, which is