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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
commit08b74a000942a380fe028845f92cd3a0dee827d5 (patch)
treeaa78b4e12607c3e1fcce8d5cc42df4330792f118 /debian/patches-rt/0187-fs-dcache-Use-cpu_chill-in-trylock-loops.patch
parentAdding upstream version 4.19.249. (diff)
downloadlinux-08b74a000942a380fe028845f92cd3a0dee827d5.tar.xz
linux-08b74a000942a380fe028845f92cd3a0dee827d5.zip
Adding debian version 4.19.249-2.debian/4.19.249-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/patches-rt/0187-fs-dcache-Use-cpu_chill-in-trylock-loops.patch')
-rw-r--r--debian/patches-rt/0187-fs-dcache-Use-cpu_chill-in-trylock-loops.patch66
1 files changed, 66 insertions, 0 deletions
diff --git a/debian/patches-rt/0187-fs-dcache-Use-cpu_chill-in-trylock-loops.patch b/debian/patches-rt/0187-fs-dcache-Use-cpu_chill-in-trylock-loops.patch
new file mode 100644
index 000000000..2df32b031
--- /dev/null
+++ b/debian/patches-rt/0187-fs-dcache-Use-cpu_chill-in-trylock-loops.patch
@@ -0,0 +1,66 @@
+From d12da2a9ddfd2e6803327ef9856a63caedb4c653 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Wed, 7 Mar 2012 21:00:34 +0100
+Subject: [PATCH 187/347] fs: dcache: Use cpu_chill() in trylock 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. Use cpu_chill() instead of cpu_relax() to let the system
+make progress.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+---
+ fs/autofs/expire.c | 3 ++-
+ fs/namespace.c | 8 ++++++--
+ 2 files changed, 8 insertions(+), 3 deletions(-)
+
+diff --git a/fs/autofs/expire.c b/fs/autofs/expire.c
+index 70e9afe589fb..1a6b88ad4fe0 100644
+--- a/fs/autofs/expire.c
++++ b/fs/autofs/expire.c
+@@ -8,6 +8,7 @@
+ * option, any later version, incorporated herein by reference.
+ */
+
++#include <linux/delay.h>
+ #include "autofs_i.h"
+
+ /* Check if a dentry can be expired */
+@@ -153,7 +154,7 @@ static struct dentry *get_next_positive_dentry(struct dentry *prev,
+ parent = p->d_parent;
+ if (!spin_trylock(&parent->d_lock)) {
+ spin_unlock(&p->d_lock);
+- cpu_relax();
++ cpu_chill();
+ goto relock;
+ }
+ spin_unlock(&p->d_lock);
+diff --git a/fs/namespace.c b/fs/namespace.c
+index 396ff1bcfdad..2c0ff275e978 100644
+--- a/fs/namespace.c
++++ b/fs/namespace.c
+@@ -14,6 +14,7 @@
+ #include <linux/mnt_namespace.h>
+ #include <linux/user_namespace.h>
+ #include <linux/namei.h>
++#include <linux/delay.h>
+ #include <linux/security.h>
+ #include <linux/cred.h>
+ #include <linux/idr.h>
+@@ -327,8 +328,11 @@ int __mnt_want_write(struct vfsmount *m)
+ * incremented count after it has set MNT_WRITE_HOLD.
+ */
+ smp_mb();
+- while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)
+- cpu_relax();
++ while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) {
++ preempt_enable();
++ cpu_chill();
++ preempt_disable();
++ }
+ /*
+ * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
+ * be set to match its requirements. So we must not load that until
+--
+2.36.1
+