The patch titled
SRCU: report out-of-memory errors
has been added to the -mm tree. Its filename is
srcu-report-out-of-memory-errors.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: SRCU: report out-of-memory errors
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Currently the init_srcu_struct() routine has no way to report out-of-memory
errors. This patch (as761) makes it return -ENOMEM when the per-cpu data
allocation fails.
The patch also makes srcu_init_notifier_head() report a BUG if a notifier
head can't be initialized. Perhaps it should return -ENOMEM instead, but
in the most likely cases where this might occur I don't think any recovery
is possible. Notifier chains generally are not created dynamically.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/srcu.h | 2 +-
kernel/srcu.c | 5 +++--
kernel/sys.c | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)
diff -puN include/linux/srcu.h~srcu-report-out-of-memory-errors include/linux/srcu.h
--- a/include/linux/srcu.h~srcu-report-out-of-memory-errors
+++ a/include/linux/srcu.h
@@ -43,7 +43,7 @@ struct srcu_struct {
#define srcu_barrier()
#endif /* #else #ifndef CONFIG_PREEMPT */
-void init_srcu_struct(struct srcu_struct *sp);
+int init_srcu_struct(struct srcu_struct *sp);
void cleanup_srcu_struct(struct srcu_struct *sp);
int srcu_read_lock(struct srcu_struct *sp);
void srcu_read_unlock(struct srcu_struct *sp, int idx);
diff -puN kernel/srcu.c~srcu-report-out-of-memory-errors kernel/srcu.c
--- a/kernel/srcu.c~srcu-report-out-of-memory-errors
+++ a/kernel/srcu.c
@@ -42,11 +42,12 @@
* to any other function. Each srcu_struct represents a separate domain
* of SRCU protection.
*/
-void init_srcu_struct(struct srcu_struct *sp)
+int init_srcu_struct(struct srcu_struct *sp)
{
sp->completed = 0;
- sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
mutex_init(&sp->mutex);
+ sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
+ return (sp->per_cpu_ref ? 0 : -ENOMEM);
}
/*
diff -puN kernel/sys.c~srcu-report-out-of-memory-errors kernel/sys.c
--- a/kernel/sys.c~srcu-report-out-of-memory-errors
+++ a/kernel/sys.c
@@ -516,7 +516,7 @@ EXPORT_SYMBOL_GPL(srcu_notifier_call_cha
void srcu_init_notifier_head(struct srcu_notifier_head *nh)
{
mutex_init(&nh->mutex);
- init_srcu_struct(&nh->srcu);
+ BUG_ON(init_srcu_struct(&nh->srcu) < 0);
nh->head = NULL;
}
_
Patches currently in -mm which might be from stern@xxxxxxxxxxxxxxxxxxx are
e100-disable-interrupts-at-boot.patch
usb-hub-driver-improve-use-of-ifdef-fix.patch
properly-unregister-reboot-notifier-in-case-of-failure-in-ehci-hcd.patch
uhci-dont-test-the-short-packet-detect-bit.patch
block-layer-early-detection-of-medium-not-present.patch
scsi-core-and-sd-early-detection-of-medium-not-present.patch
sd-early-detection-of-medium-not-present.patch
scsi-early-detection-of-medium-not-present-updated.patch
add-srcu-based-notifier-chains.patch
srcu-report-out-of-memory-errors.patch
srcu-report-out-of-memory-errors-fixlet.patch
-
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