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| author | Tejun Heo <tj@kernel.org> | 2010-07-22 14:14:25 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-07-22 22:39:22 +0200 |
| commit | e120153ddf8620fd0a194d301e9c5a8b28483bb5 (patch) | |
| tree | 953ef1a61ca29d0486a6c8c3bb72dd8bbc080419 /include/linux | |
| parent | f2e005aaff4878a8ea93d5fb033a21389b72579a (diff) | |
| download | blackbird-op-linux-e120153ddf8620fd0a194d301e9c5a8b28483bb5.tar.gz blackbird-op-linux-e120153ddf8620fd0a194d301e9c5a8b28483bb5.zip | |
workqueue: fix how cpu number is stored in work->data
Once a work starts execution, its data contains the cpu number it was
on instead of pointing to cwq. This is added by commit 7a22ad75
(workqueue: carry cpu number in work data once execution starts) to
reliably determine the work was last on even if the workqueue itself
was destroyed inbetween.
Whether data points to a cwq or contains a cpu number was
distinguished by comparing the value against PAGE_OFFSET. The
assumption was that a cpu number should be below PAGE_OFFSET while a
pointer to cwq should be above it. However, on architectures which
use separate address spaces for user and kernel spaces, this doesn't
hold as PAGE_OFFSET is zero.
Fix it by using an explicit flag, WORK_STRUCT_CWQ, to mark what the
data field contains. If the flag is set, it's pointing to a cwq;
otherwise, it contains a cpu number.
Reported on s390 and microblaze during linux-next testing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Reported-by: Michal Simek <michal.simek@petalogix.com>
Reported-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Tested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Tested-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/workqueue.h | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index d74a529ed13e..5f76001c4e6d 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -25,17 +25,19 @@ typedef void (*work_func_t)(struct work_struct *work); enum { WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */ - WORK_STRUCT_LINKED_BIT = 1, /* next work is linked to this one */ + WORK_STRUCT_CWQ_BIT = 1, /* data points to cwq */ + WORK_STRUCT_LINKED_BIT = 2, /* next work is linked to this one */ #ifdef CONFIG_DEBUG_OBJECTS_WORK - WORK_STRUCT_STATIC_BIT = 2, /* static initializer (debugobjects) */ - WORK_STRUCT_COLOR_SHIFT = 3, /* color for workqueue flushing */ + WORK_STRUCT_STATIC_BIT = 3, /* static initializer (debugobjects) */ + WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */ #else - WORK_STRUCT_COLOR_SHIFT = 2, /* color for workqueue flushing */ + WORK_STRUCT_COLOR_SHIFT = 3, /* color for workqueue flushing */ #endif WORK_STRUCT_COLOR_BITS = 4, WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT, + WORK_STRUCT_CWQ = 1 << WORK_STRUCT_CWQ_BIT, WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT, #ifdef CONFIG_DEBUG_OBJECTS_WORK WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT, @@ -56,8 +58,8 @@ enum { WORK_CPU_LAST = WORK_CPU_NONE, /* - * Reserve 6 bits off of cwq pointer w/ debugobjects turned - * off. This makes cwqs aligned to 64 bytes which isn't too + * Reserve 7 bits off of cwq pointer w/ debugobjects turned + * off. This makes cwqs aligned to 128 bytes which isn't too * excessive while allowing 15 workqueue flush colors. */ WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT + |
