104 lines
2.7 KiB
Diff
104 lines
2.7 KiB
Diff
From d39668f051f7e84544a47125e7459ee3afac604a Mon Sep 17 00:00:00 2001
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Wed, 7 Mar 2012 21:00:34 +0100
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Subject: [PATCH 259/290] fs: dcache: Use cpu_chill() in trylock loops
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Retry loops on RT might loop forever when the modifying side was
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preempted. Use cpu_chill() instead of cpu_relax() to let the system
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make progress.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Cc: stable-rt@vger.kernel.org
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---
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fs/autofs4/autofs_i.h | 1 +
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fs/autofs4/expire.c | 2 +-
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fs/dcache.c | 7 ++++---
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fs/namespace.c | 3 ++-
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4 files changed, 8 insertions(+), 5 deletions(-)
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diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
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index 650d520..fb77639 100644
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--- a/fs/autofs4/autofs_i.h
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+++ b/fs/autofs4/autofs_i.h
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@@ -34,6 +34,7 @@
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#include <linux/sched.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
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+#include <linux/delay.h>
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#include <asm/current.h>
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#include <asm/uaccess.h>
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diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
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index 450f529..43afbb0 100644
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--- a/fs/autofs4/expire.c
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+++ b/fs/autofs4/expire.c
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@@ -170,7 +170,7 @@ again:
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parent = p->d_parent;
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if (!spin_trylock(&parent->d_lock)) {
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spin_unlock(&p->d_lock);
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- cpu_relax();
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+ cpu_chill();
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goto relock;
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}
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spin_unlock(&p->d_lock);
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diff --git a/fs/dcache.c b/fs/dcache.c
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index 63c0c6b..152184c 100644
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--- a/fs/dcache.c
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+++ b/fs/dcache.c
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@@ -37,6 +37,7 @@
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#include <linux/rculist_bl.h>
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#include <linux/prefetch.h>
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#include <linux/ratelimit.h>
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+#include <linux/delay.h>
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#include "internal.h"
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/*
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@@ -410,7 +411,7 @@ static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
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if (inode && !spin_trylock(&inode->i_lock)) {
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relock:
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spin_unlock(&dentry->d_lock);
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- cpu_relax();
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+ cpu_chill();
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return dentry; /* try again with same dentry */
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}
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if (IS_ROOT(dentry))
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@@ -796,7 +797,7 @@ relock:
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if (!spin_trylock(&dentry->d_lock)) {
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spin_unlock(&dcache_lru_lock);
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- cpu_relax();
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+ cpu_chill();
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goto relock;
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}
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@@ -1979,7 +1980,7 @@ again:
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if (dentry->d_count == 1) {
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if (inode && !spin_trylock(&inode->i_lock)) {
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spin_unlock(&dentry->d_lock);
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- cpu_relax();
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+ cpu_chill();
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goto again;
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}
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dentry->d_flags &= ~DCACHE_CANT_MOUNT;
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diff --git a/fs/namespace.c b/fs/namespace.c
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index 644dbde..c45da77 100644
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--- a/fs/namespace.c
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+++ b/fs/namespace.c
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@@ -31,6 +31,7 @@
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#include <linux/idr.h>
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#include <linux/fs_struct.h>
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#include <linux/fsnotify.h>
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+#include <linux/delay.h>
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#include <asm/uaccess.h>
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#include <asm/unistd.h>
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#include "pnode.h"
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@@ -346,7 +347,7 @@ int mnt_want_write(struct vfsmount *mnt)
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*/
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while (mnt->mnt_flags & MNT_WRITE_HOLD) {
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preempt_enable();
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- cpu_relax();
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+ cpu_chill();
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preempt_disable();
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}
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/*
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