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authorPaul E. McKenney <paulmck@kernel.org>2022-08-03 01:32:47 +0300
committerPaul E. McKenney <paulmck@kernel.org>2022-08-31 15:10:15 +0300
commit5fe89191e43fb37e874b8e5177fb2a5c72379b06 (patch)
tree79e8da6c41a1828c7dca12c6c3aad7704ea80ad4 /kernel/rcu/srcutiny.c
parentde3f2671ae563d24c679dcca36c9e0ebd9564ebd (diff)
downloadlinux-5fe89191e43fb37e874b8e5177fb2a5c72379b06.tar.xz
srcu: Make Tiny SRCU use full-sized grace-period counters
This commit makes Tiny SRCU use full-sized grace-period counters to further avoid counter-wrap issues when using polled grace-period APIs. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/srcutiny.c')
-rw-r--r--kernel/rcu/srcutiny.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index a2af24f21467..33adafdad261 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -117,7 +117,7 @@ void srcu_drive_gp(struct work_struct *wp)
struct srcu_struct *ssp;
ssp = container_of(wp, struct srcu_struct, srcu_work);
- if (ssp->srcu_gp_running || USHORT_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
+ if (ssp->srcu_gp_running || ULONG_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
return; /* Already running or nothing to do. */
/* Remove recently arrived callbacks and wait for readers. */
@@ -150,17 +150,17 @@ void srcu_drive_gp(struct work_struct *wp)
* straighten that out.
*/
WRITE_ONCE(ssp->srcu_gp_running, false);
- if (USHORT_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
+ if (ULONG_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
schedule_work(&ssp->srcu_work);
}
EXPORT_SYMBOL_GPL(srcu_drive_gp);
static void srcu_gp_start_if_needed(struct srcu_struct *ssp)
{
- unsigned short cookie;
+ unsigned long cookie;
cookie = get_state_synchronize_srcu(ssp);
- if (USHORT_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie))
+ if (ULONG_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie))
return;
WRITE_ONCE(ssp->srcu_idx_max, cookie);
if (!READ_ONCE(ssp->srcu_gp_running)) {
@@ -215,7 +215,7 @@ unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp)
barrier();
ret = (READ_ONCE(ssp->srcu_idx) + 3) & ~0x1;
barrier();
- return ret & USHRT_MAX;
+ return ret;
}
EXPORT_SYMBOL_GPL(get_state_synchronize_srcu);
@@ -240,10 +240,10 @@ EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu);
*/
bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie)
{
- unsigned short cur_s = READ_ONCE(ssp->srcu_idx);
+ unsigned long cur_s = READ_ONCE(ssp->srcu_idx);
barrier();
- return USHORT_CMP_GE(cur_s, cookie) || USHORT_CMP_LT(cur_s, cookie - 3);
+ return ULONG_CMP_GE(cur_s, cookie) || ULONG_CMP_LT(cur_s, cookie - 3);
}
EXPORT_SYMBOL_GPL(poll_state_synchronize_srcu);