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workqueue: BH workqueue conversions for v6.9

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This pull request contains two patches that convert tasklet users to BH
 workqueue - backtractest and usb hcd. DM conversions are being routed
 through the respective subsystem tree. Hopefully, the next cycle will see a
 lot more conversions.
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Merge tag 'wq-for-6.9-bh-conversions' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue BH conversions from Tejun Heo:
 "This contains two patches that convert tasklet users to BH workqueues:
  backtracetest and usb hcd.

  DM conversions are being routed through the respective subsystem tree.
  Hopefully, the next cycle will see a lot more conversions"

* tag 'wq-for-6.9-bh-conversions' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  usb: core: hcd: Convert from tasklet to BH workqueue
  backtracetest: Convert from tasklet to BH workqueue
This commit is contained in:
Linus Torvalds 2024-03-11 13:05:19 -07:00
commit 1a1e09890c
3 changed files with 20 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/usb/core/hcd.c
View File

@ -1664,9 +1664,10 @@ static void __usb_hcd_giveback_urb(struct urb *urb)
usb_put_urb(urb);
}
static void usb_giveback_urb_bh(struct tasklet_struct *t)
static void usb_giveback_urb_bh(struct work_struct *work)
{
struct giveback_urb_bh *bh = from_tasklet(bh, t, bh);
struct giveback_urb_bh *bh =
container_of(work, struct giveback_urb_bh, bh);
struct list_head local_list;
spin_lock_irq(&bh->lock);
@ -1691,9 +1692,9 @@ static void usb_giveback_urb_bh(struct tasklet_struct *t)
spin_lock_irq(&bh->lock);
if (!list_empty(&bh->head)) {
if (bh->high_prio)
tasklet_hi_schedule(&bh->bh);
queue_work(system_bh_highpri_wq, &bh->bh);
else
tasklet_schedule(&bh->bh);
queue_work(system_bh_wq, &bh->bh);
}
bh->running = false;
spin_unlock_irq(&bh->lock);
@ -1706,7 +1707,7 @@ static void usb_giveback_urb_bh(struct tasklet_struct *t)
* @status: completion status code for the URB.
*
* Context: atomic. The completion callback is invoked in caller's context.
* For HCDs with HCD_BH flag set, the completion callback is invoked in tasklet
* For HCDs with HCD_BH flag set, the completion callback is invoked in BH
* context (except for URBs submitted to the root hub which always complete in
* caller's context).
*
@ -1725,7 +1726,7 @@ void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
struct giveback_urb_bh *bh;
bool running;
/* pass status to tasklet via unlinked */
/* pass status to BH via unlinked */
if (likely(!urb->unlinked))
urb->unlinked = status;
@ -1747,9 +1748,9 @@ void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
if (running)
;
else if (bh->high_prio)
tasklet_hi_schedule(&bh->bh);
queue_work(system_bh_highpri_wq, &bh->bh);
else
tasklet_schedule(&bh->bh);
queue_work(system_bh_wq, &bh->bh);
}
EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
@ -2540,7 +2541,7 @@ static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
spin_lock_init(&bh->lock);
INIT_LIST_HEAD(&bh->head);
tasklet_setup(&bh->bh, usb_giveback_urb_bh);
INIT_WORK(&bh->bh, usb_giveback_urb_bh);
}
struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
@ -2926,7 +2927,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
&& device_can_wakeup(&hcd->self.root_hub->dev))
dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
/* initialize tasklets */
/* initialize BHs */
init_giveback_urb_bh(&hcd->high_prio_bh);
hcd->high_prio_bh.high_prio = true;
init_giveback_urb_bh(&hcd->low_prio_bh);
@ -3036,7 +3037,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
mutex_unlock(&usb_bus_idr_lock);
/*
* tasklet_kill() isn't needed here because:
* flush_work() isn't needed here because:
* - driver's disconnect() called from usb_disconnect() should
* make sure its URBs are completed during the disconnect()
* callback

2
include/linux/usb/hcd.h
View File

@ -55,7 +55,7 @@ struct giveback_urb_bh {
bool high_prio;
spinlock_t lock;
struct list_head head;
struct tasklet_struct bh;
struct work_struct bh;
struct usb_host_endpoint *completing_ep;
};

18
kernel/backtracetest.c
View File

@ -21,24 +21,20 @@ static void backtrace_test_normal(void)
dump_stack();
}
static DECLARE_COMPLETION(backtrace_work);
static void backtrace_test_irq_callback(unsigned long data)
static void backtrace_test_bh_workfn(struct work_struct *work)
{
dump_stack();
complete(&backtrace_work);
}
static DECLARE_TASKLET_OLD(backtrace_tasklet, &backtrace_test_irq_callback);
static DECLARE_WORK(backtrace_bh_work, &backtrace_test_bh_workfn);
static void backtrace_test_irq(void)
static void backtrace_test_bh(void)
{
pr_info("Testing a backtrace from irq context.\n");
pr_info("Testing a backtrace from BH context.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
init_completion(&backtrace_work);
tasklet_schedule(&backtrace_tasklet);
wait_for_completion(&backtrace_work);
queue_work(system_bh_wq, &backtrace_bh_work);
flush_work(&backtrace_bh_work);
}
#ifdef CONFIG_STACKTRACE
@ -65,7 +61,7 @@ static int backtrace_regression_test(void)
pr_info("====[ backtrace testing ]===========\n");
backtrace_test_normal();
backtrace_test_irq();
backtrace_test_bh();
backtrace_test_saved();
pr_info("====[ end of backtrace testing ]====\n");