aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/process.c
AgeCommit message (Collapse)Author
2008-08-04powerpc: Remove use of CONFIG_PPC_MERGEKumar Gala
Now that arch/ppc is gone and CONFIG_PPC_MERGE is always set, remove the dead code associated with !CONFIG_PPC_MERGE from arch/powerpc and include/asm-powerpc. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-28powerpc/booke: Clean up the hardware watchpoint supportKumar Gala
* CONFIG_BOOKE is selected by CONFIG_44x so we dont need both * Fixed a few comments * Go back to only using DBCR0_IDM to determine if we are using debug resources. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-25powerpc: BookE hardware watchpoint supportLuis Machado
This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-15powerpc: fix giveup_vsx to save registers correctlyMichael Neuling
giveup_vsx didn't save the FPU and VMX regsiters. Change it to be like giveup_fpr/altivec which save these registers. Also update call sites where FPU and VMX are already saved to use the original giveup_vsx (renamed to __giveup_vsx). Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-09powerpc: Use new printk extension %pS to print symbols on oopsBenjamin Herrenschmidt
This changes the oops and backtrace code to use the new %pS printk extension to print out symbols rather than manually calling print_symbol. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-03powerpc: Remove old dump_task_* functionsMichael Neuling
Since Roland's ptrace cleanup starting with commit f65255e8d51ecbc6c9eef20d39e0377d19b658ca ("[POWERPC] Use user_regset accessors for FP regs"), the dump_task_* functions are no longer being used. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Update for VSX core file and ptraceMichael Neuling
This correctly hooks the VSX dump into Roland McGrath core file infrastructure. It adds the VSX dump information as an additional elf note in the core file (after talking more to the tool chain/gdb guys). This also ensures the formats are consistent between signals, ptrace and core files. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Add VSX context save/restore, ptrace and signal supportMichael Neuling
This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Add macros to access floating point registers in thread_struct.Michael Neuling
We are going to change where the floating point registers are stored in the thread_struct, so in preparation add some macros to access the floating point registers. Update all code to use these new macros. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-29[POWERPC] Add IRQSTACKS support on ppc32Kumar Gala
This makes it possible to use separate stacks for hard and soft IRQs on 32-bit powerpc as well as on 64-bit. The code for 32-bit is just the 32-bit analog of the 64-bit code. * Added allocation and initialization of the irq stacks. We limit the stacks to be in lowmem for ppc32. * Implemented ppc32 versions of call_do_softirq() and call_handle_irq() to switch the stack pointers * Reworked how we do stack overflow detection. We now keep around the limit of the stack in the thread_struct and compare against the limit to see if we've overflowed. We can now use this on ppc64 if desired. [ paulus@samba.org: Fixed bug on 6xx where we need to reload r9 with the thread_info pointer. ] Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24[POWERPC] Fix kernel stack allocation alignmentBenjamin Herrenschmidt
The powerpc kernel stacks need to be naturally aligned, as they contain the thread info at the bottom, which is obtained by clearing the low bits of the stack pointer. However, when using 64K pages, the stack is smaller than a page, so we use kmalloc to allocate it, but that doesn't provide the alignment guarantee we need. It appeared to work so far... until one enables SLUB debugging which then returns unaligned pointers. Ooops... This fixes it by using a slab cache with enforced alignment. It relies on my previous patch that adds a thread_info_cache_init() callback. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-18[POWERPC] Move stackframe definitions to common headerBenjamin Herrenschmidt
This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-14Merge branch 'linux-2.6'Paul Mackerras
2008-03-28[POWERPC] Fix missed hardware breakpoints across multiple threadsMichael Ellerman
There is a bug in the powerpc DABR (data access breakpoint) handling, which can result in us missing breakpoints if several threads are trying to break on the same address. The circumstances are that do_page_fault() calls do_dabr(), this clears the DABR (sets it to 0) and sets up the signal which will report to userspace that the DABR was hit. The do_signal() code will restore the DABR value on the way out to userspace. If we reschedule before calling do_signal(), __switch_to() will check the cached DABR value and compare it to the new thread's value, if they match we don't set the DABR in hardware. So if two threads have the same DABR value, and we schedule from one to the other after taking the interrupt for the first thread hitting the DABR, the second thread will run without the DABR set in hardware. The cleanest fix is to move the cache update into set_dabr(), that way we can't forget to do it. Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-26Merge branch 'linux-2.6'Paul Mackerras
2008-03-26[POWERPC] Don't touch PT_DTRACE in execRoland McGrath
The PT_DTRACE flag is meaningless and obsolete. Don't touch it. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-20[POWERPC] Fix PMU + soft interrupt disable bugAnton Blanchard
Since the PMU is an NMI now, it can come at any time we are only soft disabled. We must hard disable around the two places we allow the kernel stack SLB and r1 to go out of sync. Otherwise the PMU exception can force a kernel stack SLB into another slot, which can lead to it getting evicted, which can lead to a nasty unrecoverable SLB miss in the exception entry code. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-14[POWERPC] Fix DEBUG_PREEMPT warning when warningHugh Dickins
The powerpc show_regs prints CPU using smp_processor_id: change that to raw_smp_processor_id, so that when it's showing a WARN_ON backtrace without preemption disabled, DEBUG_PREEMPT doesn't mess up that warning with its own. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-12-06[POWERPC] Fix hardware IRQ time accounting problem.Tony Breeds
The commit fa13a5a1f25f671d084d8884be96fc48d9b68275 (sched: restore deterministic CPU accounting on powerpc), unconditionally calls update_process_tick() in system context. In the deterministic accounting case this is the correct thing to do. However, in the non-deterministic accounting case we need to not do this, since doing this results in the time accounted as hardware irq time being artificially elevated. Also this collapses 2 consecutive '#ifdef CONFIG_VIRT_CPU_ACCOUNTING' checks in time.h into one for neatness. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-11-09sched: restore deterministic CPU accounting on powerpcPaul Mackerras
Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been broken on powerpc, because we end up counting user time twice: once in timer_interrupt() and once in update_process_times(). This fixes the problem by pulling the code in update_process_times that updates utime and stime into a separate function called account_process_tick. If CONFIG_VIRT_CPU_ACCOUNTING is not defined, there is a version of account_process_tick in kernel/timer.c that simply accounts a whole tick to either utime or stime as before. If CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to implement account_process_tick. This also lets us simplify the s390 code a bit; it means that the s390 timer interrupt can now call update_process_times even when CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a suitable account_process_tick(). account_process_tick() now takes the task_struct * as an argument. Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-19Use helpers to obtain task pid in printks (arch code)Alexey Dobriyan
One of the easiest things to isolate is the pid printed in kernel log. There was a patch, that made this for arch-independent code, this one makes so for arch/xxx files. It took some time to cross-compile it, but hopefully these are all the printks in arch code. Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17powerpc: add Altivec/VMX state to coredumpsMark Nelson
Update dump_task_altivec() (which has so far never been put to use) so that it dumps the Altivec/VMX registers (VR[0] - VR[31], VSCR and VRSAVE) in the same format as the ptrace get_vrregs(), and add the appropriate glue typedef and #defines to make it work. A new note type of NT_PPC_VMX was chosen to be 0x100 (arbitrarily) because it allows the low range values to be used for more generic purposes and 0x100 seems an adequate starting point for PowerPC extensions. Signed-off-by: Mark Nelson <markn@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-12[POWERPC] Use 1TB segmentsPaul Mackerras
This makes the kernel use 1TB segments for all kernel mappings and for user addresses of 1TB and above, on machines which support them (currently POWER5+, POWER6 and PA6T). We detect that the machine supports 1TB segments by looking at the ibm,processor-segment-sizes property in the device tree. We don't currently use 1TB segments for user addresses < 1T, since that would effectively prevent 32-bit processes from using huge pages unless we also had a way to revert to using 256MB segments. That would be possible but would involve extra complications (such as keeping track of which segment size was used when HPTEs were inserted) and is not addressed here. Parts of this patch were originally written by Ben Herrenschmidt. Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-10-03Merge branch 'linux-2.6' into for-2.6.24Paul Mackerras
2007-10-03[POWERPC] Make instruction dumping work in real modeScott Wood
On non-book-E, exceptions execute in real mode. If a fault happens that leads to a register dump, the kernel currently prints XXXXXXXX because it doesn't realize that PC is a physical address. This patch checks whether instruction address translation is turned on, and if not converts PC into a virtual address. Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-25[POWERPC] Ensure FULL_REGS on execRoland McGrath
When PTRACE_O_TRACEEXEC is used, a ptrace call to fetch the registers at the PTRACE_EVENT_EXEC stop (PTRACE_PEEKUSR) will oops in CHECK_FULL_REGS. With recent versions, "gdb --args /bin/sh -c 'exec /bin/true'" and "run" at the (gdb) prompt is sufficient to produce this. I also have written an isolated test case, see https://bugzilla.redhat.com/show_bug.cgi?id=301791#c15. This change fixes the problem by clearing the low bit of pt_regs.trap in start_thread so that FULL_REGS is true again. This is correct since all of the GPRs that "full" refers to are cleared in start_thread. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-14[POWERPC] Add cpu feature for SPE handlingKumar Gala
Make it so that SPE support can be determined at runtime. This is similiar to how we handle AltiVec. This allows us to have SPE support built in and work on processors with and without SPE. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-08-28[POWERPC] Flush registers to proper task contextKumar Gala
When we flush register state for FP, Altivec, or SPE in flush_*_to_thread we need to respect the task_struct that the caller has passed to us. Most cases we are called with current, however sometimes (ptrace) we may be passed a different task_struct. This showed up when using gdbserver debugging a simple program that used floating point. When gdb tried to show the FP regs they all showed up as 0, because the child's FP registers were never properly flushed to memory. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-07-26[POWERPC] Fix register labels on show_regs() message for 4xx/Book-EKumar Gala
In a show_regs() message The DEAR and ESR were reported as DAR and DSISR which only exist on classic parts. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-06-14[POWERPC] Always apply DABR changes on context switchesBenjamin Herrenschmidt
This patch removes the #ifdef CONFIG_PPC64 around setting the DABR. The actual setting of the SPR inside of the set_dabr() function is dependent on CONFIG_PPC64 || CONFIG_6xx but you can always provide a ppc_md hook to override that. We should improve support for different HW breakpoints facilities but this is a first step. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-05-08header cleaning: don't include smp_lock.h when not usedRandy Dunlap
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-13[POWERPC] Make tlb flush batch use lazy MMU modeBenjamin Herrenschmidt
The current tlb flush code on powerpc 64 bits has a subtle race since we lost the page table lock due to the possible faulting in of new PTEs after a previous one has been removed but before the corresponding hash entry has been evicted, which can leads to all sort of fatal problems. This patch reworks the batch code completely. It doesn't use the mmu_gather stuff anymore. Instead, we use the lazy mmu hooks that were added by the paravirt code. They have the nice property that the enter/leave lazy mmu mode pair is always fully contained by the PTE lock for a given range of PTEs. Thus we can guarantee that all batches are flushed on a given CPU before it drops that lock. We also generalize batching for any PTE update that require a flush. Batching is now enabled on a CPU by arch_enter_lazy_mmu_mode() and disabled by arch_leave_lazy_mmu_mode(). The code epects that this is always contained within a PTE lock section so no preemption can happen and no PTE insertion in that range from another CPU. When batching is enabled on a CPU, every PTE updates that need a hash flush will use the batch for that flush. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-04-13Merge branch 'linux-2.6' into for-2.6.22Paul Mackerras
2007-03-26[POWERPC] Use lowercase for hex printouts in oops messages.anton@samba.org
Use lowercase for hex printouts in oops messages. The number of times I have tried to copy and paste from an oops into an objdump search... Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-22[POWERPC] Remove last_syscallAnton Blanchard
Remove last_syscall from 32bit powerpc, its been gone in 64bit for years. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-16[POWERPC] Fix atomicity of TIF update in flush_thread()Mathieu Desnoyers
Fix atomicity of TIF update in flush_thread() for powerpc Fixes it correctly with *_ti_thread_flag. Race : parent process executing : sys_ptrace() (lock_kernel()) (ptrace_get_task_struct(pid)) arch_ptrace() ptrace_detach() ptrace_disable(child); clear_singlestep(child); clear_tsk_thread_flag(child, TIF_SINGLESTEP); (which clears the TIF_SINGLESTEP flag atomically from a different process) (put_task_struct(child)) (unlock_kernel()) And at the same time, in the child process : sys_execve() do_execve() search_binary_handler() load_elf_binary() flush_old_exec() flush_thread() doing a non-atomic thread flag update Applies on 2.6.20. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-08[POWERPC] Harden validate_sp against stack corruptionPaul Mackerras
If something has overflowed or corrupted the stack and causes an oops, and we try to print a stack trace, that will call validate_sp, which can itself cause an oops if the cpu field of the thread_info struct at the bottom of the stack has been corrupted (if CONFIG_IRQSTACKS is set). This makes debugging harder. To avoid the second oops, this adds a check to make sure that the cpu number is reasonable before using it to check whether the stack is on the softirq or hardirq stack. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-16[POWERPC] Better check in show_instructionsAnton Blanchard
Instead of just checking that an address is in the right range, use the provided __kernel_text_address() helper which covers both the kernel and module text sections. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-02[PATCH] namespaces: utsname: use init_utsname when appropriateSerge E. Hallyn
In some places, particularly drivers and __init code, the init utsns is the appropriate one to use. This patch replaces those with a the init_utsname helper. Changes: Removed several uses of init_utsname(). Hope I picked all the right ones in net/ipv4/ipconfig.c. These are now changed to utsname() (the per-process namespace utsname) in the previous patch (2/7) [akpm@osdl.org: CIFS fix] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-09[PATCH] powerpc: Implement PR_[GS]ET_UNALIGN prctls for powerpcPaul Mackerras
This gives the ability to control whether alignment exceptions get fixed up or reported to the process as a SIGBUS, using the existing PR_SET_UNALIGN and PR_GET_UNALIGN prctls. We do not implement the option of logging a message on alignment exceptions. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-09[PATCH] powerpc: Implement support for setting little-endian mode via prctlPaul Mackerras
This adds the PowerPC part of the code to allow processes to change their endian mode via prctl. This also extends the alignment exception handler to be able to fix up alignment exceptions that occur in little-endian mode, both for "PowerPC" little-endian and true little-endian. We always enter signal handlers in big-endian mode -- the support for little-endian mode does not amount to the creation of a little-endian user/kernel ABI. If the signal handler returns, the endian mode is restored to what it was when the signal was delivered. We have two new kernel CPU feature bits, one for PPC little-endian and one for true little-endian. Most of the classic 32-bit processors support PPC little-endian, and this is reflected in the CPU feature table. There are two corresponding feature bits reported to userland in the AT_HWCAP aux vector entry. This is based on an earlier patch by Anton Blanchard. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-31[PATCH] unexport get_wchanAdrian Bunk
The only user of get_wchan is the proc fs - and proc can't be built modular. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28[PATCH] powerpc: export validate_sp for oprofile calltraceAnton Blanchard
Export validate_sp so we can use it in the oprofile calltrace code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27[PATCH] powerpc: declare arch syscalls in <asm/syscalls.h>Arnd Bergmann
powerpc currently declares some of its own system calls in <asm/unistd.h>, but not all of them. That place also contains remainders of the now almost unused kernel syscall hack. - Add a new <asm/syscalls.h> with clean declarations - Include that file from every source that implements one of these - Get rid of old declarations in <asm/unistd.h> This patch is required as a base for implementing system calls from an SPU, but also makes sense as a general cleanup. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27[PATCH] powerpc: fix various sparse warningsStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-26[PATCH] kretprobe instance recycled by parent processbibo mao
When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-24powerpc: Implement accurate task and CPU time accountingPaul Mackerras
This implements accurate task and cpu time accounting for 64-bit powerpc kernels. Instead of accounting a whole jiffy of time to a task on a timer interrupt because that task happened to be running at the time, we now account time in units of timebase ticks according to the actual time spent by the task in user mode and kernel mode. We also count the time spent processing hardware and software interrupts accurately. This is conditional on CONFIG_VIRT_CPU_ACCOUNTING. If that is not set, we do tick-based approximate accounting as before. To get this accurate information, we read either the PURR (processor utilization of resources register) on POWER5 machines, or the timebase on other machines on * each entry to the kernel from usermode * each exit to usermode * transitions between process context, hard irq context and soft irq context in kernel mode * context switches. On POWER5 systems with shared-processor logical partitioning we also read both the PURR and the timebase at each timer interrupt and context switch in order to determine how much time has been taken by the hypervisor to run other partitions ("steal" time). Unfortunately, since we need values of the PURR on both threads at the same time to accurately calculate the steal time, and since we can only calculate steal time on a per-core basis, the apportioning of the steal time between idle time (time which we ceded to the hypervisor in the idle loop) and actual stolen time is somewhat approximate at the moment. This is all based quite heavily on what s390 does, and it uses the generic interfaces that were added by the s390 developers, i.e. account_system_time(), account_user_time(), etc. This patch doesn't add any new interfaces between the kernel and userspace, and doesn't change the units in which time is reported to userspace by things such as /proc/stat, /proc/<pid>/stat, getrusage(), times(), etc. Internally the various task and cpu times are stored in timebase units, but they are converted to USER_HZ units (1/100th of a second) when reported to userspace. Some precision is therefore lost but there should not be any accumulating error, since the internal accumulation is at full precision. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24Merge ../powerpc-mergePaul Mackerras
2006-02-24[PATCH] powerpc: Fix runlatch performance issuesAnton Blanchard
The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>