On Thu, Mar 28, 2024 at 10:52:16AM -0700, Allen wrote: > On Wed, Mar 27, 2024 at 11:05 AM Corey Minyard <minyard@xxxxxxx> wrote: > > > > I believe that work queues items are execute single-threaded for a work > > queue, so this should be good. I need to test this, though. It may be > > that an IPMI device can have its own work queue; it may not be important > > to run it in bh context. > > Fair point. Could you please let me know once you have had a chance to test > these changes. Meanwhile, I will work on RFC wherein IPMI will have its own > workqueue. > > Thanks for taking time out to review. After looking and thinking about it a bit, a BH context is still probably the best for this. I have tested this patch under load and various scenarios and it seems to work ok. So: Tested-by: Corey Minyard <cminyard@xxxxxxxxxx> Acked-by: Corey Minyard <cminyard@xxxxxxxxxx> Or I can take this into my tree. -corey > > - Allen > > > > > -corey > > > > > > > > Based on the work done by Tejun Heo <tj@xxxxxxxxxx> > > > Branch: https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-610 > > > > > > Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx> > > > --- > > > drivers/char/ipmi/ipmi_msghandler.c | 30 ++++++++++++++--------------- > > > 1 file changed, 15 insertions(+), 15 deletions(-) > > > > > > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c > > > index b0eedc4595b3..fce2a2dbdc82 100644 > > > --- a/drivers/char/ipmi/ipmi_msghandler.c > > > +++ b/drivers/char/ipmi/ipmi_msghandler.c > > > @@ -36,12 +36,13 @@ > > > #include <linux/nospec.h> > > > #include <linux/vmalloc.h> > > > #include <linux/delay.h> > > > +#include <linux/workqueue.h> > > > > > > #define IPMI_DRIVER_VERSION "39.2" > > > > > > static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void); > > > static int ipmi_init_msghandler(void); > > > -static void smi_recv_tasklet(struct tasklet_struct *t); > > > +static void smi_recv_work(struct work_struct *t); > > > static void handle_new_recv_msgs(struct ipmi_smi *intf); > > > static void need_waiter(struct ipmi_smi *intf); > > > static int handle_one_recv_msg(struct ipmi_smi *intf, > > > @@ -498,13 +499,13 @@ struct ipmi_smi { > > > /* > > > * Messages queued for delivery. If delivery fails (out of memory > > > * for instance), They will stay in here to be processed later in a > > > - * periodic timer interrupt. The tasklet is for handling received > > > + * periodic timer interrupt. The work is for handling received > > > * messages directly from the handler. > > > */ > > > spinlock_t waiting_rcv_msgs_lock; > > > struct list_head waiting_rcv_msgs; > > > atomic_t watchdog_pretimeouts_to_deliver; > > > - struct tasklet_struct recv_tasklet; > > > + struct work_struct recv_work; > > > > > > spinlock_t xmit_msgs_lock; > > > struct list_head xmit_msgs; > > > @@ -704,7 +705,7 @@ static void clean_up_interface_data(struct ipmi_smi *intf) > > > struct cmd_rcvr *rcvr, *rcvr2; > > > struct list_head list; > > > > > > - tasklet_kill(&intf->recv_tasklet); > > > + cancel_work_sync(&intf->recv_work); > > > > > > free_smi_msg_list(&intf->waiting_rcv_msgs); > > > free_recv_msg_list(&intf->waiting_events); > > > @@ -1319,7 +1320,7 @@ static void free_user(struct kref *ref) > > > { > > > struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); > > > > > > - /* SRCU cleanup must happen in task context. */ > > > + /* SRCU cleanup must happen in work context. */ > > > queue_work(remove_work_wq, &user->remove_work); > > > } > > > > > > @@ -3605,8 +3606,7 @@ int ipmi_add_smi(struct module *owner, > > > intf->curr_seq = 0; > > > spin_lock_init(&intf->waiting_rcv_msgs_lock); > > > INIT_LIST_HEAD(&intf->waiting_rcv_msgs); > > > - tasklet_setup(&intf->recv_tasklet, > > > - smi_recv_tasklet); > > > + INIT_WORK(&intf->recv_work, smi_recv_work); > > > atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0); > > > spin_lock_init(&intf->xmit_msgs_lock); > > > INIT_LIST_HEAD(&intf->xmit_msgs); > > > @@ -4779,7 +4779,7 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) > > > * To preserve message order, quit if we > > > * can't handle a message. Add the message > > > * back at the head, this is safe because this > > > - * tasklet is the only thing that pulls the > > > + * work is the only thing that pulls the > > > * messages. > > > */ > > > list_add(&smi_msg->link, &intf->waiting_rcv_msgs); > > > @@ -4812,10 +4812,10 @@ static void handle_new_recv_msgs(struct ipmi_smi *intf) > > > } > > > } > > > > > > -static void smi_recv_tasklet(struct tasklet_struct *t) > > > +static void smi_recv_work(struct work_struct *t) > > > { > > > unsigned long flags = 0; /* keep us warning-free. */ > > > - struct ipmi_smi *intf = from_tasklet(intf, t, recv_tasklet); > > > + struct ipmi_smi *intf = from_work(intf, t, recv_work); > > > int run_to_completion = intf->run_to_completion; > > > struct ipmi_smi_msg *newmsg = NULL; > > > > > > @@ -4866,7 +4866,7 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, > > > > > > /* > > > * To preserve message order, we keep a queue and deliver from > > > - * a tasklet. > > > + * a work. > > > */ > > > if (!run_to_completion) > > > spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags); > > > @@ -4887,9 +4887,9 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, > > > spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags); > > > > > > if (run_to_completion) > > > - smi_recv_tasklet(&intf->recv_tasklet); > > > + smi_recv_work(&intf->recv_work); > > > else > > > - tasklet_schedule(&intf->recv_tasklet); > > > + queue_work(system_bh_wq, &intf->recv_work); > > > } > > > EXPORT_SYMBOL(ipmi_smi_msg_received); > > > > > > @@ -4899,7 +4899,7 @@ void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf) > > > return; > > > > > > atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1); > > > - tasklet_schedule(&intf->recv_tasklet); > > > + queue_work(system_bh_wq, &intf->recv_work); > > > } > > > EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout); > > > > > > @@ -5068,7 +5068,7 @@ static bool ipmi_timeout_handler(struct ipmi_smi *intf, > > > flags); > > > } > > > > > > - tasklet_schedule(&intf->recv_tasklet); > > > + queue_work(system_bh_wq, &intf->recv_work); > > > > > > return need_timer; > > > } > > > -- > > > 2.17.1 > > > > > > > > > > > -- > - Allen >
