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| author | Christoph Lameter <christoph@lameter.com> | 2005-06-24 23:13:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-25 17:10:13 -0700 |
| commit | 3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73 (patch) | |
| tree | d1e7c1e2e8902072042aefc3a7976b271cf76021 /drivers/usb | |
| parent | b3e112bcc19abd8e9657dca34a87316786e096f3 (diff) | |
| download | linux-3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73.tar.gz linux-3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73.tar.bz2 linux-3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73.zip | |
[PATCH] Cleanup patch for process freezing
1. Establish a simple API for process freezing defined in linux/include/sched.h:
frozen(process) Check for frozen process
freezing(process) Check if a process is being frozen
freeze(process) Tell a process to freeze (go to refrigerator)
thaw_process(process) Restart process
frozen_process(process) Process is frozen now
2. Remove all references to PF_FREEZE and PF_FROZEN from all
kernel sources except sched.h
3. Fix numerous locations where try_to_freeze is manually done by a driver
4. Remove the argument that is no longer necessary from two function calls.
5. Some whitespace cleanup
6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
cleared before setting PF_FROZEN, recalc_sigpending does not check
PF_FROZEN).
This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/core/hub.c | 2 | ||||
| -rw-r--r-- | drivers/usb/gadget/file_storage.c | 3 | ||||
| -rw-r--r-- | drivers/usb/storage/usb.c | 4 |
3 files changed, 3 insertions, 6 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index d2d648ee8640..a8d879a85d04 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2808,7 +2808,7 @@ static int hub_thread(void *__unused) do { hub_events(); wait_event_interruptible(khubd_wait, !list_empty(&hub_event_list)); - try_to_freeze(PF_FREEZE); + try_to_freeze(); } while (!signal_pending(current)); pr_debug ("%s: khubd exiting\n", usbcore_name); diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c index 037a7f163822..a9be85103d23 100644 --- a/drivers/usb/gadget/file_storage.c +++ b/drivers/usb/gadget/file_storage.c @@ -1554,8 +1554,7 @@ static int sleep_thread(struct fsg_dev *fsg) rc = wait_event_interruptible(fsg->thread_wqh, fsg->thread_wakeup_needed); fsg->thread_wakeup_needed = 0; - if (current->flags & PF_FREEZE) - refrigerator(PF_FREEZE); + try_to_freeze(); return (rc ? -EINTR : 0); } diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 35c1ca6b5a8e..77e7fc258aa2 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -847,10 +847,8 @@ retry: wait_event_interruptible_timeout(us->delay_wait, test_bit(US_FLIDX_DISCONNECTING, &us->flags), delay_use * HZ); - if (current->flags & PF_FREEZE) { - refrigerator(PF_FREEZE); + if (try_to_freeze()) goto retry; - } } /* If the device is still connected, perform the scanning */ |