diff options
Diffstat (limited to 'debian/patches-rt/0186-block-Use-cpu_chill-for-retry-loops.patch')
| -rw-r--r-- | debian/patches-rt/0186-block-Use-cpu_chill-for-retry-loops.patch | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/debian/patches-rt/0186-block-Use-cpu_chill-for-retry-loops.patch b/debian/patches-rt/0186-block-Use-cpu_chill-for-retry-loops.patch new file mode 100644 index 000000000..1e0c86edd --- /dev/null +++ b/debian/patches-rt/0186-block-Use-cpu_chill-for-retry-loops.patch @@ -0,0 +1,51 @@ +From f13997a9d1ad83528116e8daabc9b2247530ec63 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 20 Dec 2012 18:28:26 +0100 +Subject: [PATCH 186/347] block: Use cpu_chill() for retry loops +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +Retry loops on RT might loop forever when the modifying side was +preempted. Steven also observed a live lock when there was a +concurrent priority boosting going on. + +Use cpu_chill() instead of cpu_relax() to let the system +make progress. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +--- + block/blk-ioc.c | 5 +++-- + 1 file changed, 3 insertions(+), 2 deletions(-) + +diff --git a/block/blk-ioc.c b/block/blk-ioc.c +index 4c810969c3e2..48089f5bcc11 100644 +--- a/block/blk-ioc.c ++++ b/block/blk-ioc.c +@@ -9,6 +9,7 @@ + #include <linux/blkdev.h> + #include <linux/slab.h> + #include <linux/sched/task.h> ++#include <linux/delay.h> + + #include "blk.h" + +@@ -119,7 +120,7 @@ static void ioc_release_fn(struct work_struct *work) + spin_unlock(q->queue_lock); + } else { + spin_unlock_irqrestore(&ioc->lock, flags); +- cpu_relax(); ++ cpu_chill(); + spin_lock_irqsave_nested(&ioc->lock, flags, 1); + } + } +@@ -203,7 +204,7 @@ void put_io_context_active(struct io_context *ioc) + spin_unlock(icq->q->queue_lock); + } else { + spin_unlock_irqrestore(&ioc->lock, flags); +- cpu_relax(); ++ cpu_chill(); + goto retry; + } + } +-- +2.36.1 + |