The patch titled
uml: fix unreasonably long udelay
has been added to the -mm tree. Its filename is
uml-fix-unreasonably-long-udelay.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: uml: fix unreasonably long udelay
From: "Paolo 'Blaisorblade' Giarrusso" <blaisorblade@xxxxxxxx>
Currently we have a confused udelay implementation.
* __const_udelay does not accept usecs but xloops in i386 and x86_64
* our implementation requires usecs as arg
* it gets a xloops count when called by asm/arch/delay.h
Bugs related to this (extremely long shutdown times) where reported by some
x86_64 users, especially using Device Mapper.
To hit this bug, a compile-time constant time parameter must be passed -
that's why UML seems to work most times. Fix this with a simple udelay
implementation.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>
Cc: Jeff Dike <jdike@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/um/sys-i386/delay.c | 11 -----------
arch/um/sys-x86_64/delay.c | 11 -----------
include/asm-um/delay.h | 17 ++++++++++++++---
3 files changed, 14 insertions(+), 25 deletions(-)
diff -puN arch/um/sys-i386/delay.c~uml-fix-unreasonably-long-udelay arch/um/sys-i386/delay.c
--- a/arch/um/sys-i386/delay.c~uml-fix-unreasonably-long-udelay
+++ a/arch/um/sys-i386/delay.c
@@ -27,14 +27,3 @@ void __udelay(unsigned long usecs)
}
EXPORT_SYMBOL(__udelay);
-
-void __const_udelay(unsigned long usecs)
-{
- int i, n;
-
- n = (loops_per_jiffy * HZ * usecs) / MILLION;
- for(i=0;i<n;i++)
- cpu_relax();
-}
-
-EXPORT_SYMBOL(__const_udelay);
diff -puN arch/um/sys-x86_64/delay.c~uml-fix-unreasonably-long-udelay arch/um/sys-x86_64/delay.c
--- a/arch/um/sys-x86_64/delay.c~uml-fix-unreasonably-long-udelay
+++ a/arch/um/sys-x86_64/delay.c
@@ -28,14 +28,3 @@ void __udelay(unsigned long usecs)
}
EXPORT_SYMBOL(__udelay);
-
-void __const_udelay(unsigned long usecs)
-{
- unsigned long i, n;
-
- n = (loops_per_jiffy * HZ * usecs) / MILLION;
- for(i=0;i<n;i++)
- cpu_relax();
-}
-
-EXPORT_SYMBOL(__const_udelay);
diff -puN include/asm-um/delay.h~uml-fix-unreasonably-long-udelay include/asm-um/delay.h
--- a/include/asm-um/delay.h~uml-fix-unreasonably-long-udelay
+++ a/include/asm-um/delay.h
@@ -1,9 +1,20 @@
#ifndef __UM_DELAY_H
#define __UM_DELAY_H
-#include "asm/arch/delay.h"
-#include "asm/archparam.h"
-
#define MILLION 1000000
+/* Undefined on purpose */
+extern void __bad_udelay(void);
+
+extern void __udelay(unsigned long usecs);
+extern void __delay(unsigned long loops);
+
+#define udelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
+ __bad_udelay() : __udelay(n))
+
+/* It appears that ndelay is not used at all for UML, and has never been
+ * implemented. */
+extern void __unimplemented_ndelay(void);
+#define ndelay(n) __unimplemented_ndelay()
+
#endif
_
Patches currently in -mm which might be from blaisorblade@xxxxxxxx are
uml-fix-static-linking.patch
uml-use-correct-register-file-size-everywhere.patch
uml-fix-i-o-hang-when-multiple-devices-are-in-use.patch
uml-fix-device-unplug-crash.patch
uml-fix-pte-bit-collision.patch
uml-irq-locking-fixes.patch
uml-fix-lvm-crash.patch
uml-fix-compilation-problems.patch
uml-hostfs-variable-renaming.patch
uml-fix-unreasonably-long-udelay.patch
uml-delete-unused-code.patch
uml-formatting-fixes.patch
uml-host_info-tidying.patch
uml-mark-tt-mode-code-for-future-removal.patch
uml-print-coredump-limits.patch
uml-handle-block-device-hotplug-errors.patch
uml-driver-formatting-fixes.patch
uml-driver-formatting-fixes-fix.patch
uml-network-interface-hotplug-error-handling.patch
uml-fix-prototypes.patch
uml-move-sigio-testing-to-sigioc.patch
uml-create-archh.patch
uml-create-as-layouth.patch
uml-move-remaining-useful-contents-of-user_utilh.patch
uml-remove-user_utilh.patch
uml-add-missing-__init-declarations.patch
remove-unused-header-file-arch-um-kernel-tt-include-mode_kern-tth.patch
uml-improve-checking-and-diagnostics-of-ethernet-macs.patch
uml-eliminate-temporary-buffer-in-eth_configure.patch
uml-replace-one-element-array-with-zero-element-array.patch
fix-utrace-utrace-tracehook-um.patch
git-gccbug.patch
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