[Devel] Re: [PATCH 1/6] Container Freezer: Add TIF_FREEZE flag to all architectures
Matt Helsley
matthltc at us.ibm.com
Fri Aug 1 15:05:25 PDT 2008
On Fri, 2008-08-01 at 14:32 +0200, Cedric Le Goater wrote:
> Nigel Cunningham wrote:
> > Hi.
> >
> > On Thu, 2008-07-31 at 22:07 -0700, Matt Helsley wrote:
> >> This patch is the first step in making the refrigerator() available
> >> to all architectures, even for those without power management.
> >>
> >> The purpose of such a change is to be able to use the refrigerator()
> >> in a new control group subsystem which will implement a control group
> >> freezer.
> >
> > Is there a reason for always using 19, rather than just the next
> > available bit?
>
> At the time I did the patch, it was to be consistent with the other
> arches supporting suspend but this can not be true anymore. So we might
> as well just use the next available bit as you suggest.
>
> Thanks,
>
> C.
This is a good point.
I did a quick survey of the thread_info*.h headers. Most archs appear
to use the MSW/LSW to distinguish "pending work-to-be-done" (LSW) vs.
other flags (MSW). This explains most of the gaps in thread flag
assignment. In some other cases the bits are allocated based on whether
the arch asm code uses asm immediate values to test the flag. sparc64 is
by far the most elaborate and includes some excellent comments to
explain the situation.
The gaps in allocated flag bit assignments not explained in
thread_info*.h comments are:
mips doesn't use bit 0, there's a gap between 4 and 9, and another gap
between 24 and 31.
m32r has a gap between bit 4 and bit 8.
ia64 has a gap at bit 5.
blackfin doesn't explicitly mention the MSW/LSW distinction but appears
to follow it.
arm also doesn't mention MSW/LSW but appears consistent with that
explanation.
avr32 makes the MSW/LSW distinction but this doesn't fully explain
jumping from bit 8 to bit 30 unless they're allocating numbers in the
opposite direction within the MSW (highest flag is bit 31).
m68k starts at 6 and the comments don't explain why. At first glance it
doesn't appear to be because of m68knommu. It also jumps from bit 7 to
bit 14 without explanation and appears to not follow the MSW/LSW
convention.
cris has an inexplicable gap between bit 3 and bit 9.
s390 has a gap at bit 1. It appears to follow the MSW/LSW distinction
but doesn't mention it in a comment.
x86 has a gap at bit 9.
"sparc32" has a gap between 4 and 8.
So I've modified the flag numbers to follow apparent conventions of each
arch as best I can tell given the lack of explanation above.
------------
From: Cedric Le Goater <clg at fr.ibm.com>
Subject: Container Freezer: Add TIF_FREEZE flag to all architectures
This patch is the first step in making the refrigerator() available
to all architectures, even for those without power management.
The purpose of such a change is to be able to use the refrigerator()
in a new control group subsystem which will implement a control group
freezer.
Signed-off-by: Cedric Le Goater <clg at fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc at us.ibm.com>
Acked-by: Pavel Machek <pavel at suse.cz>
Acked-by: Serge E. Hallyn <serue at us.ibm.com>
Tested-by: Matt Helsley <matthltc at us.ibm.com>
---
arch/parisc/include/asm/thread_info.h | 2 ++
arch/sparc/include/asm/thread_info_32.h | 2 ++
arch/sparc/include/asm/thread_info_64.h | 2 ++
include/asm-alpha/thread_info.h | 2 ++
include/asm-avr32/thread_info.h | 1 +
include/asm-cris/thread_info.h | 2 ++
include/asm-h8300/thread_info.h | 2 ++
include/asm-m68k/thread_info.h | 1 +
include/asm-m68knommu/thread_info.h | 2 ++
include/asm-s390/thread_info.h | 2 ++
include/asm-um/thread_info.h | 2 ++
include/asm-xtensa/thread_info.h | 2 ++
12 files changed, 22 insertions(+)
Index: linux-2.6.27-rc1-mm1/arch/sparc/include/asm/thread_info_32.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/arch/sparc/include/asm/thread_info_32.h
+++ linux-2.6.27-rc1-mm1/arch/sparc/include/asm/thread_info_32.h
@@ -139,6 +139,7 @@ BTFIXUPDEF_CALL(void, free_thread_info,
#define TIF_POLLING_NRFLAG 9 /* true if poll_idle() is polling
* TIF_NEED_RESCHED */
#define TIF_MEMDIE 10
+#define TIF_FREEZE 11 /* is freezing for suspend */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -152,6 +153,7 @@ BTFIXUPDEF_CALL(void, free_thread_info,
#define _TIF_DO_NOTIFY_RESUME_MASK (_TIF_NOTIFY_RESUME | \
_TIF_SIGPENDING | \
_TIF_RESTORE_SIGMASK)
+#define TIF_FREEZE (1<<TIF_FREEZE)
#endif /* __KERNEL__ */
Index: linux-2.6.27-rc1-mm1/arch/sparc/include/asm/thread_info_64.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/arch/sparc/include/asm/thread_info_64.h
+++ linux-2.6.27-rc1-mm1/arch/sparc/include/asm/thread_info_64.h
@@ -237,6 +237,7 @@ register struct thread_info *current_thr
#define TIF_ABI_PENDING 12
#define TIF_MEMDIE 13
#define TIF_POLLING_NRFLAG 14
+#define TIF_FREEZE 15 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
@@ -249,6 +250,7 @@ register struct thread_info *current_thr
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_USER_WORK_MASK ((0xff << TI_FLAG_WSAVED_SHIFT) | \
_TIF_DO_NOTIFY_RESUME_MASK | \
Index: linux-2.6.27-rc1-mm1/include/asm-alpha/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-alpha/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-alpha/thread_info.h
@@ -74,12 +74,14 @@ register struct thread_info *__current_t
#define TIF_UAC_SIGBUS 7
#define TIF_MEMDIE 8
#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal */
+#define TIF_FREEZE 16 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
/* Work to do on interrupt/exception return. */
#define _TIF_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
Index: linux-2.6.27-rc1-mm1/include/asm-avr32/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-avr32/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-avr32/thread_info.h
@@ -96,6 +96,7 @@ static inline struct thread_info *curren
#define _TIF_MEMDIE (1 << TIF_MEMDIE)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_CPU_GOING_TO_SLEEP (1 << TIF_CPU_GOING_TO_SLEEP)
+#define _TIF_FREEZE (1 << TIF_FREEZE)
/* Note: The masks below must never span more than 16 bits! */
Index: linux-2.6.27-rc1-mm1/include/asm-cris/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-cris/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-cris/thread_info.h
@@ -88,6 +88,7 @@ struct thread_info {
#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17
+#define TIF_FREEZE 18 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
@@ -95,6 +96,7 @@ struct thread_info {
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
Index: linux-2.6.27-rc1-mm1/include/asm-h8300/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-h8300/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-h8300/thread_info.h
@@ -89,6 +89,7 @@ static inline struct thread_info *curren
TIF_NEED_RESCHED */
#define TIF_MEMDIE 4
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
+#define TIF_FREEZE 16 /* is freezing for suspend */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -96,6 +97,7 @@ static inline struct thread_info *curren
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
Index: linux-2.6.27-rc1-mm1/include/asm-m68k/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-m68k/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-m68k/thread_info.h
@@ -52,5 +52,6 @@ struct thread_info {
#define TIF_DELAYED_TRACE 14 /* single step a syscall */
#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
#define TIF_MEMDIE 16
+#define TIF_FREEZE 17 /* thread is freezing for suspend */
#endif /* _ASM_M68K_THREAD_INFO_H */
Index: linux-2.6.27-rc1-mm1/include/asm-m68knommu/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-m68knommu/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-m68knommu/thread_info.h
@@ -84,12 +84,14 @@ static inline struct thread_info *curren
#define TIF_POLLING_NRFLAG 3 /* true if poll_idle() is polling
TIF_NEED_RESCHED */
#define TIF_MEMDIE 4
+#define TIF_FREEZE 16 /* is freezing for suspend */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
Index: linux-2.6.27-rc1-mm1/include/asm-s390/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-s390/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-s390/thread_info.h
@@ -98,6 +98,7 @@ static inline struct thread_info *curren
#define TIF_31BIT 18 /* 32bit process */
#define TIF_MEMDIE 19
#define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */
+#define TIF_FREEZE 21 /* thread is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
@@ -110,6 +111,7 @@ static inline struct thread_info *curren
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_31BIT (1<<TIF_31BIT)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
#endif /* __KERNEL__ */
Index: linux-2.6.27-rc1-mm1/include/asm-um/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-um/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-um/thread_info.h
@@ -69,6 +69,7 @@ static inline struct thread_info *curren
#define TIF_MEMDIE 5
#define TIF_SYSCALL_AUDIT 6
#define TIF_RESTORE_SIGMASK 7
+#define TIF_FREEZE 16 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
@@ -77,5 +78,6 @@ static inline struct thread_info *curren
#define _TIF_MEMDIE (1 << TIF_MEMDIE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
+#define _TIF_FREEZE (1 << TIF_FREEZE)
#endif
Index: linux-2.6.27-rc1-mm1/include/asm-xtensa/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/include/asm-xtensa/thread_info.h
+++ linux-2.6.27-rc1-mm1/include/asm-xtensa/thread_info.h
@@ -134,6 +134,7 @@ static inline struct thread_info *curren
#define TIF_MEMDIE 5
#define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_FREEZE 17 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
@@ -142,6 +143,7 @@ static inline struct thread_info *curren
#define _TIF_IRET (1<<TIF_IRET)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
+#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
Index: linux-2.6.27-rc1-mm1/arch/parisc/include/asm/thread_info.h
===================================================================
--- linux-2.6.27-rc1-mm1.orig/arch/parisc/include/asm/thread_info.h
+++ linux-2.6.27-rc1-mm1/arch/parisc/include/asm/thread_info.h
@@ -58,6 +58,7 @@ struct thread_info {
#define TIF_32BIT 4 /* 32 bit binary */
#define TIF_MEMDIE 5
#define TIF_RESTORE_SIGMASK 6 /* restore saved signal mask */
+#define TIF_FREEZE 7 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
@@ -65,6 +66,7 @@ struct thread_info {
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_32BIT (1 << TIF_32BIT)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
+#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | \
_TIF_NEED_RESCHED | _TIF_RESTORE_SIGMASK)
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