Re: [PATCH 1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex
On Monday, October 24, 2016 3:34:27 PM CEST Binoy Jayan wrote: > Hi Arnd > > On 20 October 2016 at 14:36, Arnd Bergmann wrote: > > On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote: > >> Semaphores are going away in the future, so replace the semaphore > >> sync_request_sem with the a mutex lock. timeout_msecs is not used > >> for the lock sync_request_sem, so remove the timed locking too. > >> > >> Signed-off-by: Binoy Jayan > > > > The patch looks correct to me, but I think if you remove the support > > for handling timeouts, you should update the prototype of > > pqi_submit_raid_request_synchronous to no longer pass the timeout > > argument in the first place. > > But we still need "timeout_msecs" in a call to > pqi_submit_raid_request_synchronous_with_io_request() > > drivers/scsi/smartpqi/smartpqi_init.c +3484 Why? If it's always zero, we can remove that too. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex
On 20 October 2016 at 14:40, Arnd Bergmann wrote: > On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote: >> - sema_init(&ctrl_info->sync_request_sem, >> - PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS); >> + mutex_init(&ctrl_info->sync_request_mutex); >> > > Looking at this again, I see that PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS > is '3', so this is in fact a counting semaphore rather than a mutex, > and the conversion is changing the behavior. > > The patch can't go in unless you either show that it should be > a normal mutex rather than a counting semaphore, or you find a way > to keep the behavior the same. This still holds true, will try changing this accordingly. -Binoy -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex
Hi Arnd On 20 October 2016 at 14:36, Arnd Bergmann wrote: > On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote: >> Semaphores are going away in the future, so replace the semaphore >> sync_request_sem with the a mutex lock. timeout_msecs is not used >> for the lock sync_request_sem, so remove the timed locking too. >> >> Signed-off-by: Binoy Jayan > > The patch looks correct to me, but I think if you remove the support > for handling timeouts, you should update the prototype of > pqi_submit_raid_request_synchronous to no longer pass the timeout > argument in the first place. But we still need "timeout_msecs" in a call to pqi_submit_raid_request_synchronous_with_io_request() drivers/scsi/smartpqi/smartpqi_init.c +3484 -Binoy -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex
On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote: > - sema_init(&ctrl_info->sync_request_sem, > - PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS); > + mutex_init(&ctrl_info->sync_request_mutex); > Looking at this again, I see that PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS is '3', so this is in fact a counting semaphore rather than a mutex, and the conversion is changing the behavior. The patch can't go in unless you either show that it should be a normal mutex rather than a counting semaphore, or you find a way to keep the behavior the same. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex
On Thursday, October 20, 2016 2:24:01 PM CEST Binoy Jayan wrote: > Semaphores are going away in the future, so replace the semaphore > sync_request_sem with the a mutex lock. timeout_msecs is not used > for the lock sync_request_sem, so remove the timed locking too. > > Signed-off-by: Binoy Jayan The patch looks correct to me, but I think if you remove the support for handling timeouts, you should update the prototype of pqi_submit_raid_request_synchronous to no longer pass the timeout argument in the first place. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 1/2] scsi: smartpqi: Replace semaphore sync_request_sem with mutex
Semaphores are going away in the future, so replace the semaphore sync_request_sem with the a mutex lock. timeout_msecs is not used for the lock sync_request_sem, so remove the timed locking too. Signed-off-by: Binoy Jayan --- drivers/scsi/smartpqi/smartpqi.h | 4 +++- drivers/scsi/smartpqi/smartpqi_init.c | 31 ++- 2 files changed, 9 insertions(+), 26 deletions(-) diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index 07b6444..b4559b1 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -19,6 +19,8 @@ #if !defined(_SMARTPQI_H) #define _SMARTPQI_H +#include + #pragma pack(1) #define PQI_DEVICE_SIGNATURE "PQI DREG" @@ -961,7 +963,7 @@ struct pqi_ctrl_info { unsigned intnum_heartbeats_requested; struct timer_list heartbeat_timer; - struct semaphore sync_request_sem; + struct mutex sync_request_mutex; struct semaphore lun_reset_sem; }; diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index a535b26..4974f7e 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -3444,29 +3444,11 @@ static int pqi_submit_raid_request_synchronous(struct pqi_ctrl_info *ctrl_info, unsigned long msecs_blocked; size_t iu_length; - /* -* Note that specifying PQI_SYNC_FLAGS_INTERRUPTABLE and a timeout value -* are mutually exclusive. -*/ - - if (flags & PQI_SYNC_FLAGS_INTERRUPTABLE) { - if (down_interruptible(&ctrl_info->sync_request_sem)) + if (flags & PQI_SYNC_FLAGS_INTERRUPTABLE) + if (mutex_lock_interruptible(&ctrl_info->sync_request_mutex)) return -ERESTARTSYS; - } else { - if (timeout_msecs == NO_TIMEOUT) { - down(&ctrl_info->sync_request_sem); - } else { - start_jiffies = jiffies; - if (down_timeout(&ctrl_info->sync_request_sem, - msecs_to_jiffies(timeout_msecs))) - return -ETIMEDOUT; - msecs_blocked = - jiffies_to_msecs(jiffies - start_jiffies); - if (msecs_blocked >= timeout_msecs) - return -ETIMEDOUT; - timeout_msecs -= msecs_blocked; - } - } + else + mutex_lock(&ctrl_info->sync_request_mutex); io_request = pqi_alloc_io_request(ctrl_info); @@ -3508,7 +3490,7 @@ static int pqi_submit_raid_request_synchronous(struct pqi_ctrl_info *ctrl_info, pqi_free_io_request(io_request); - up(&ctrl_info->sync_request_sem); + mutex_unlock(&ctrl_info->sync_request_mutex); return rc; } @@ -5540,8 +5522,7 @@ static struct pqi_ctrl_info *pqi_alloc_ctrl_info(int numa_node) INIT_DELAYED_WORK(&ctrl_info->rescan_work, pqi_rescan_worker); INIT_DELAYED_WORK(&ctrl_info->update_time_work, pqi_update_time_worker); - sema_init(&ctrl_info->sync_request_sem, - PQI_RESERVED_IO_SLOTS_SYNCHRONOUS_REQUESTS); + mutex_init(&ctrl_info->sync_request_mutex); sema_init(&ctrl_info->lun_reset_sem, PQI_RESERVED_IO_SLOTS_LUN_RESET); ctrl_info->ctrl_id = atomic_inc_return(&pqi_controller_count) - 1; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html