diff options
Diffstat (limited to 'kernel/srcu.c')
| -rw-r--r-- | kernel/srcu.c | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/kernel/srcu.c b/kernel/srcu.c index a43211c92863..b9088524935a 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -266,16 +266,16 @@ EXPORT_SYMBOL_GPL(__srcu_read_unlock); * we repeatedly block for 1-millisecond time periods. This approach * has done well in testing, so there is no need for a config parameter. */ -#define SYNCHRONIZE_SRCU_READER_DELAY 5 +#define SYNCHRONIZE_SRCU_READER_DELAY 5 +#define SYNCHRONIZE_SRCU_TRYCOUNT 2 +#define SYNCHRONIZE_SRCU_EXP_TRYCOUNT 12 /* * Wait until all pre-existing readers complete. Such readers * will have used the index specified by "idx". */ -static void wait_idx(struct srcu_struct *sp, int idx, bool expedited) +static void wait_idx(struct srcu_struct *sp, int idx, int trycount) { - int trycount = 0; - /* * SRCU read-side critical sections are normally short, so wait * a small amount of time before possibly blocking. @@ -283,9 +283,10 @@ static void wait_idx(struct srcu_struct *sp, int idx, bool expedited) if (!srcu_readers_active_idx_check(sp, idx)) { udelay(SYNCHRONIZE_SRCU_READER_DELAY); while (!srcu_readers_active_idx_check(sp, idx)) { - if (expedited && ++ trycount < 10) + if (trycount > 0) { + trycount--; udelay(SYNCHRONIZE_SRCU_READER_DELAY); - else + } else schedule_timeout_interruptible(1); } } @@ -299,7 +300,7 @@ static void srcu_flip(struct srcu_struct *sp) /* * Helper function for synchronize_srcu() and synchronize_srcu_expedited(). */ -static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) +static void __synchronize_srcu(struct srcu_struct *sp, int trycount) { int busy_idx; @@ -319,8 +320,8 @@ static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) * have completed: * * __synchronize_srcu() { - * wait_idx(sp, 0, expedited); - * wait_idx(sp, 1, expedited); + * wait_idx(sp, 0, trycount); + * wait_idx(sp, 1, trycount); * } * * Starvation is prevented by the fact that we flip the index. @@ -344,13 +345,13 @@ static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) * this call to wait_idx(), which waits on really old readers * describe in this comment above, will almost never need to wait. */ - wait_idx(sp, 1 - busy_idx, expedited); + wait_idx(sp, 1 - busy_idx, trycount); /* Flip the index to avoid reader-induced starvation. */ srcu_flip(sp); /* Wait for recent pre-existing readers. */ - wait_idx(sp, busy_idx, expedited); + wait_idx(sp, busy_idx, trycount); mutex_unlock(&sp->mutex); } @@ -371,7 +372,7 @@ static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) */ void synchronize_srcu(struct srcu_struct *sp) { - __synchronize_srcu(sp, 0); + __synchronize_srcu(sp, SYNCHRONIZE_SRCU_TRYCOUNT); } EXPORT_SYMBOL_GPL(synchronize_srcu); @@ -392,7 +393,7 @@ EXPORT_SYMBOL_GPL(synchronize_srcu); */ void synchronize_srcu_expedited(struct srcu_struct *sp) { - __synchronize_srcu(sp, 1); + __synchronize_srcu(sp, SYNCHRONIZE_SRCU_EXP_TRYCOUNT); } EXPORT_SYMBOL_GPL(synchronize_srcu_expedited); |