Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752432AbYHAWvc (ORCPT ); Fri, 1 Aug 2008 18:51:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752997AbYHAWvU (ORCPT ); Fri, 1 Aug 2008 18:51:20 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:35178 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752592AbYHAWvS (ORCPT ); Fri, 1 Aug 2008 18:51:18 -0400 From: "Rafael J. Wysocki" To: Matt Helsley Subject: Re: [PATCH 1/6] Container Freezer: Add TIF_FREEZE flag to all architectures Date: Sat, 2 Aug 2008 00:54:19 +0200 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: Cedric Le Goater , Nigel Cunningham , Andrew Morton , Paul Menage , Li Zefan , Linux-Kernel , Linux Containers , linux-pm@lists.linux-foundation.org, Pavel Machek , "Serge E. Hallyn" References: <20080801050659.924495279@us.ibm.com> <4893025D.9090801@fr.ibm.com> <1217628325.25300.270.camel@localhost.localdomain> In-Reply-To: <1217628325.25300.270.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808020054.21088.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14959 Lines: 336 On Saturday, 2 of August 2008, Matt Helsley wrote: > > 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 > 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 > Signed-off-by: Matt Helsley > Acked-by: Pavel Machek > Acked-by: Serge E. Hallyn > Tested-by: Matt Helsley Acked-by: Rafael J. Wysocki > --- > 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< @@ -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< > #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< #define _TIF_NOTIFY_RESUME (1< @@ -249,6 +250,7 @@ register struct thread_info *current_thr > #define _TIF_SYSCALL_AUDIT (1< #define _TIF_ABI_PENDING (1< #define _TIF_POLLING_NRFLAG (1< +#define _TIF_FREEZE (1< > #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< #define _TIF_SIGPENDING (1< #define _TIF_NEED_RESCHED (1< #define _TIF_POLLING_NRFLAG (1< #define _TIF_RESTORE_SIGMASK (1< +#define _TIF_FREEZE (1< > /* 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< #define _TIF_NOTIFY_RESUME (1< @@ -95,6 +96,7 @@ struct thread_info { > #define _TIF_NEED_RESCHED (1< #define _TIF_RESTORE_SIGMASK (1< #define _TIF_POLLING_NRFLAG (1< +#define _TIF_FREEZE (1< > #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< @@ -96,6 +97,7 @@ static inline struct thread_info *curren > #define _TIF_NEED_RESCHED (1< #define _TIF_POLLING_NRFLAG (1< #define _TIF_RESTORE_SIGMASK (1< +#define _TIF_FREEZE (1< > #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< #define _TIF_SIGPENDING (1< #define _TIF_NEED_RESCHED (1< #define _TIF_POLLING_NRFLAG (1< +#define _TIF_FREEZE (1< > #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< #define _TIF_RESTORE_SIGMASK (1< @@ -110,6 +111,7 @@ static inline struct thread_info *curren > #define _TIF_USEDFPU (1< #define _TIF_POLLING_NRFLAG (1< #define _TIF_31BIT (1< +#define _TIF_FREEZE (1< > #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< #define _TIF_SIGPENDING (1< @@ -142,6 +143,7 @@ static inline struct thread_info *curren > #define _TIF_IRET (1< #define _TIF_POLLING_NRFLAG (1< #define _TIF_RESTORE_SIGMASK (1< +#define _TIF_FREEZE (1< > #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) > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/