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* s390/vtime: fix increased steal time accountingGerald Schaefer2021-03-151-1/+1
| | | | | | | | | | | | | | | | Commit 152e9b8676c6e ("s390/vtime: steal time exponential moving average") inadvertently changed the input value for account_steal_time() from "cputime_to_nsecs(steal)" to just "steal", resulting in broken increased steal time accounting. Fix this by changing it back to "cputime_to_nsecs(steal)". Fixes: 152e9b8676c6e ("s390/vtime: steal time exponential moving average") Cc: <stable@vger.kernel.org> # 5.1 Reported-by: Sabine Forkel <sabine.forkel@de.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/vtime: use cpu alternative for stck/stckfHeiko Carstens2021-02-091-11/+8
| | | | | | | | | Use a cpu alternative to switch between stck and stckf instead of making it compile time dependent. This will also make kernels compiled for old machines, but running on newer machines, use stckf. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/vtime: fix inline assembly clobber listHeiko Carstens2021-02-091-1/+2
| | | | | | | | | | | | | | | The stck/stckf instruction used within the inline assembly within do_account_vtime() changes the condition code. This is not reflected with the clobber list, and therefore might result in incorrect code generation. It seems unlikely that the compiler could generate incorrect code considering the surrounding C code, but it must still be fixed. Cc: <stable@vger.kernel.org> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* sched/vtime: Consolidate IRQ time accountingFrederic Weisbecker2020-12-021-13/+32
| | | | | | | | | | | | | | | | The 3 architectures implementing CONFIG_VIRT_CPU_ACCOUNTING_NATIVE all have their own version of irq time accounting that dispatch the cputime to the appropriate index: hardirq, softirq, system, idle, guest... from an all-in-one function. Instead of having these ad-hoc versions, move the cputime destination dispatch decision to the core code and leave only the actual per-index cputime accounting to the architecture. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201202115732.27827-4-frederic@kernel.org
* s390/vtime: Use the generic IRQ entry accountingFrederic Weisbecker2020-12-021-4/+0
| | | | | | | | | | | | | | | | | | s390 has its own version of IRQ entry accounting because it doesn't account the idle time the same way the other architectures do. Only the actual idle sleep time is accounted as idle time, the rest of the idle task execution is accounted as system time. Make the generic IRQ entry accounting aware of architectures that have their own way of accounting idle time and convert s390 to use it. This prepares s390 to get involved in further consolidations of IRQ time accounting. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201202115732.27827-3-frederic@kernel.org
* sched/cputime: Remove symbol exports from IRQ time accountingFrederic Weisbecker2020-12-021-5/+5
| | | | | | | | | | | account_irq_enter_time() and account_irq_exit_time() are not called from modules. EXPORT_SYMBOL_GPL() can be safely removed from the IRQ cputime accounting functions called from there. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201202115732.27827-2-frederic@kernel.org
* sched/cputime: Rename vtime_account_system() to vtime_account_kernel()Frederic Weisbecker2019-10-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | vtime_account_system() decides if we need to account the time to the system (__vtime_account_system()) or to the guest (vtime_account_guest()). So this function is a misnomer as we are on a higher level than "system". All we know when we call that function is that we are accounting kernel cputime. Whether it belongs to guest or system time is a lower level detail. Rename this function to vtime_account_kernel(). This will clarify things and avoid too many underscored vtime_account_system() versions. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Link: https://lkml.kernel.org/r/20191003161745.28464-2-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* s390: correct some inline assembly constraintsVasily Gorbik2019-04-171-4/+4
| | | | | | | | | | Inline assembly code changed in this patch should really use "Q" constraint "Memory reference without index register and with short displacement". The kernel build with kasan instrumentation enabled might occasionally break otherwise (due to stack instrumentation). Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: steal time exponential moving averageMartin Schwidefsky2019-03-061-7/+12
| | | | | | | | To be able to judge the current overcommitment ratio for a CPU add a lowcore field with the exponential moving average of the steal time. The average is updated every tick. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cpu_mf: replace stcctm5() with the stcctm() functionHendrik Brueckner2019-02-221-2/+2
| | | | | | | | | | Remove the stcctm5() function to extract counters from the MT-diagnostic counter set with the stcctm() function. For readability, introduce an enum to map the counter sets names to respective numbers for the stcctm instruction. Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: kernel: add SPDX identifiers to the remaining filesGreg Kroah-Hartman2017-11-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kernel/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cputime: simplify account_system_index_scaledMartin Schwidefsky2017-06-121-9/+5
| | | | | | | | | The account_system_index_scaled gets two cputime values, a raw value derived from CPU timer deltas and a scaled value. The scaled value is always calculated from the raw value, the code can be simplified by moving the scale_vtime call into account_system_index_scaled. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2017-03-121-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Martin Schwidefsky: - four patches to get the new cputime code in shape for s390 - add the new statx system call - a few bug fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390: wire up statx system call KVM: s390: Fix guest migration for huge guests resulting in panic s390/ipl: always use load normal for CCW-type re-IPL s390/timex: micro optimization for tod_to_ns s390/cputime: provide archicture specific cputime_to_nsecs s390/cputime: reset all accounting fields on fork s390/cputime: remove last traces of cputime_t s390: fix in-kernel program checks s390/crypt: fix missing unlock in ctr_paes_crypt on error path
| * s390/cputime: remove last traces of cputime_tMartin Schwidefsky2017-03-011-1/+1
| | | | | | | | | | | | | | The cputime_t type is a thing of the past, replace the last occurences of the type in the s390 code with a simple u64. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | sched/headers: Prepare to move cputime functionality from <linux/sched.h> ↵Ingo Molnar2017-03-021-1/+1
|/ | | | | | | | | | | | | | | | into <linux/sched/cputime.h> Introduce a trivial, mostly empty <linux/sched/cputime.h> header to prepare for the moving of cputime functionality out of sched.h. Update all code that relies on these facilities. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* scripts/spelling.txt: add "an one" pattern and fix typo instancesMasahiro Yamada2017-02-281-1/+1
| | | | | | | | | | | | | | Fix typos and add the following to the scripts/spelling.txt: an one||a one I dropped the "an" before "one or more" in drivers/net/ethernet/sfc/mcdi_pcol.h. Link: http://lkml.kernel.org/r/1481573103-11329-6-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched/cputime: Push time to account_system_time() in nsecsFrederic Weisbecker2017-02-011-3/+3
| | | | | | | | | | | | | | | | | | | | | This is one more step toward converting cputime accounting to pure nsecs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-25-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/cputime: Push time to account_steal_time() in nsecsFrederic Weisbecker2017-02-011-1/+1
| | | | | | | | | | | | | | | | | | | | | This is one more step toward converting cputime accounting to pure nsecs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-23-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/cputime: Push time to account_user_time() in nsecsFrederic Weisbecker2017-02-011-1/+1
| | | | | | | | | | | | | | | | | | | | | This is one more step toward converting cputime accounting to pure nsecs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-22-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/cputime: Convert task/group cputime to nsecsFrederic Weisbecker2017-02-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | Now that most cputime readers use the transition API which return the task cputime in old style cputime_t, we can safely store the cputime in nsecs. This will eventually make cputime statistics less opaque and more granular. Back and forth convertions between cputime_t and nsecs in order to deal with cputime_t random granularity won't be needed anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/cputime: Rename vtime_account_user() to vtime_flush()Frederic Weisbecker2017-01-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y used to accumulate user time and account it on ticks and context switches only through the vtime_account_user() function. Now this model has been generalized on the 3 archs for all kind of cputime (system, irq, ...) and all the cputime flushing happens under vtime_account_user(). So let's rename this function to better reflect its new role. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-11-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/cputime, s390: Implement delayed accounting of system timeMartin Schwidefsky2017-01-141-48/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The account_system_time() function is called with a cputime that occurred while running in the kernel. The function detects which context the CPU is currently running in and accounts the time to the correct bucket. This forces the arch code to account the cputime for hardirq and softirq immediately. Such accounting function can be costly and perform unwelcome divisions and multiplications, among others. The arch code can delay the accounting for system time. For s390 the accounting is done once per timer tick and for each task switch. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> [ Rebase against latest linus tree and move account_system_index_scaled(). ] Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-10-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* s390/vtime: correct system time accountingMartin Schwidefsky2016-12-201-4/+4
| | | | | | | | | | | | | | There is a slight misaccounting of system time in vtime_account_user. This function is called once per HZ tick in interrupt context. The irq_enter function already accounted the system time up to the point of the irq_enter call. The system time from irq_enter until vtime_account_user/do_account_vtime is reached is irq time but it is accounted to the previous context. Just drop the hardirq offset from arch/s390/kernel/vtime.c. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-12-141-16/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The main bulk of the s390 patches for the 4.10 merge window: - Add support for the contiguous memory allocator. - The recovery for I/O errors in the dasd device driver is improved, the driver will now remove channel paths that are not working properly. - Additional fields are added to /proc/sysinfo, the extended partition name and the partition UUID. - New naming for PCI devices with system defined UIDs. - The last few remaining alloc_bootmem calls are converted to memblock. - The thread_info structure is stripped down and moved to the task_struct. The only field left in thread_info is the flags field. - Rework of the arch topology code to fix a fake numa issue. - Refactoring of the atomic primitives and add a new preempt_count implementation. - Clocksource steering for the STP sync check offsets. - The s390 specific headers are changed to make them usable with CLANG. - Bug fixes and cleanup" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (70 commits) s390/cpumf: Use configuration level indication for sampling data s390: provide memmove implementation s390: cleanup arch/s390/kernel Makefile s390: fix initrd corruptions with gcov/kcov instrumented kernels s390: exclude early C code from gcov profiling s390/dasd: channel path aware error recovery s390/dasd: extend dasd path handling s390: remove unused labels from entry.S s390/vmlogrdr: fix IUCV buffer allocation s390/crypto: unlock on error in prng_tdes_read() s390/sysinfo: show partition extended name and UUID if available s390/numa: pin all possible cpus to nodes early s390/numa: establish cpu to node mapping early s390/topology: use cpu_topology array instead of per cpu variable s390/smp: initialize cpu_present_mask in setup_arch s390/topology: always use s390 specific sched_domain_topology_level s390/smp: use smp_get_base_cpu() helper function s390/numa: always use logical cpu and core ids s390: Remove VLAIS in ptff() and clear_table() s390: fix machine check panic stack switch ...
| * s390: move cputime accounting fields from thread_info to thread_structMartin Schwidefsky2016-11-111-16/+10
| | | | | | | | | | | | | | | | | | | | The user_timer and system_timer fields are used for the per-thread cputime accounting code. The access to these values is simpler if they are moved to the thread_struct as the task_thread_info(tsk) indirection is not needed anymore. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | sched/cputime, powerpc, s390: Make scaled cputime arch specificStanislaw Gruszka2016-11-151-3/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | Only s390 and powerpc have hardware facilities allowing to measure cputimes scaled by frequency. On all other architectures utimescaled/stimescaled are equal to utime/stime (however they are accounted separately). Remove {u,s}timescaled accounting on all architectures except powerpc and s390, where those values are explicitly accounted in the proper places. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161031162143.GB12646@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* s390: add missing declarationsHeiko Carstens2016-05-101-0/+2
| | | | | | | | | arch_dup_task_struct and the per cpu variable mt_cycles are globally visible, but do not have any header file with a declaration. Therefore add it so we have proper type checking in place. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: correct scaled cputime of partially idle CPUsMartin Schwidefsky2015-09-301-29/+37
| | | | | | | | The calculation for the SMT scaling factor for a hardware thread which has been partially idle needs to disregard the cycles spent by the other threads of the core while the thread is idle. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: correct scaled cputime for SMTMartin Schwidefsky2015-09-171-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | The scaled cputime is supposed to be derived from the normal per-thread cputime by dividing it with the average thread density in the last interval. The calculation of the scaling values for the average thread density is incorrect. The current, incorrect calculation: Ci = cycle count with i active threads T = unscaled cputime, sT = scaled cputime sT = T * (C1 + C2 + ... + Cn) / (1*C1 + 2*C2 + ... + n*Cn) The calculation happens to yield the correct numbers for the simple cases with only one Ci value not zero. But for cases with multiple Ci values not zero it fails. E.g. on a SMT-2 system with one thread active half the time and two threads active for the other half of the time it fails, the scaling factor should be 3/4 but the formula gives 2/3. The correct formula is sT = T * (C1/1 + C2/2 + ... + Cn/n) / (C1 + C2 + ... + Cn) Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: limit MT scaling value updatesMartin Schwidefsky2015-08-041-1/+11
| | | | | | | | | The MT scaling values are updated on each calll to do_account_vtime. This function is called for each HZ interrupt and for each context switch. Context switch can happen often, the STCCTM instruction on this path is noticeable. Limit the updates to once per jiffy. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: add SMT supportMartin Schwidefsky2015-01-221-4/+54
| | | | | | | | | | | | | | | | | | | | The multi-threading facility is introduced with the z13 processor family. This patch adds code to detect the multi-threading facility. With the facility enabled each core will surface multiple hardware threads to the system. Each hardware threads looks like a normal CPU to the operating system with all its registers and properties. The SCLP interface reports the SMT topology indirectly via the maximum thread id. Each reported CPU in the result of a read-scp-information is a core representing a number of hardware threads. To reflect the reduced CPU capacity if two hardware threads run on a single core the MT utilization counter set is used to normalize the raw cputime obtained by the CPU timer deltas. This scaled cputime is reported via the taskstats interface. The normal /proc/stat numbers are based on the raw cputime and are not affected by the normalization. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: Get rid of redundant WARN_ONChristian Borntraeger2014-12-181-2/+0
| | | | | | | | | | | | | | in the cpu time accounting function vtime_account_irq_enter (vtime_account_system) we use a WARN_ON_ONCE(!irqs_disabled()). This is redundant as the function virt_timer_forward is always called and has a BUG_ON(!irqs_disabled()). This saves several nanoseconds in my specific testcase (KVM entry/exit) and probably all other callers like (soft)irq entry/exit. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time: use stck clock fast for do_account_vtimeMartin Schwidefsky2014-10-271-0/+4
| | | | | | | The last high frequency call site of the STCK instruction is do_account_vtime. Replace it with the faster STCKF instruction. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/idle: consolidate idle functions and definitionsMartin Schwidefsky2014-10-091-59/+1
| | | | | | | | | Move the C functions and definitions related to the idle state handling to arch/s390/include/asm/idle.h and arch/s390/kernel/idle.c. The function s390_get_idle_time is renamed to arch_cpu_idle_time and vtime_stop_cpu to enabled_wait. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/nohz: use a per-cpu flag for arch_needs_cpuMartin Schwidefsky2014-10-091-18/+1
| | | | | | | | Move the nohz_delay bit from the s390_idle data structure to the per-cpu flags. Clear the nohz delay flag in __cpu_disable and remove the cpu hotplug notifier that used to do this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtime: correct idle time calculationMartin Schwidefsky2013-10-311-1/+1
| | | | | | | | | | Use the ACCESS_ONCE macro for both accesses to idle->sequence in the loops to calculate the idle time. If only one access uses the macro, the compiler is free to cache the value for the second access which can cause endless loops. Cc: stable@vger.kernel.org # 3.6+ Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: always run the kernel in home spaceMartin Schwidefsky2013-10-241-1/+1
| | | | | | | Simplify the uaccess code by removing the user_mode=home option. The kernel will now always run in the home space mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* vtime: Describe overriden functions in dedicated arch headersFrederic Weisbecker2013-08-141-0/+1
| | | | | | | | | | | | | | | | | | | | If the arch overrides some generic vtime APIs, let it describe these on a dedicated and standalone header. This way it becomes convenient to include it in vtime generic headers without irrelevant stuff in such a low level header. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kevin Hilman <khilman@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
* s390: delete __cpuinit usage from all s390 filesPaul Gortmaker2013-07-151-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/s390 uses of the __cpuinit macros from all C files. Currently s390 does not have any __CPUINIT used in assembly files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* s390: Use generic idle loopThomas Gleixner2013-04-081-5/+0
| | | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Link: http://lkml.kernel.org/r/20130321215235.090816526@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-02-221-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 update from Martin Schwidefsky: "The most prominent change in this patch set is the software dirty bit patch for s390. It removes __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY and the page_test_and_clear_dirty primitive which makes the common memory management code a bit less obscure. Heiko fixed most of the PCI related fallout, more often than not missing GENERIC_HARDIRQS dependencies. Notable is one of the 3270 patches which adds an export to tty_io to be able to resize a tty. The rest is the usual bunch of cleanups and bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits) s390/module: Add missing R_390_NONE relocation type drivers/gpio: add missing GENERIC_HARDIRQ dependency drivers/input: add couple of missing GENERIC_HARDIRQS dependencies s390/cleanup: rename SPP to LPP s390/mm: implement software dirty bits s390/mm: Fix crst upgrade of mmap with MAP_FIXED s390/linker skript: discard exit.data at runtime drivers/media: add missing GENERIC_HARDIRQS dependency s390/bpf,jit: add vlan tag support drivers/net,AT91RM9200: add missing GENERIC_HARDIRQS dependency iucv: fix kernel panic at reboot s390/Kconfig: sort list of arch selected config options phylib: remove !S390 dependeny from Kconfig uio: remove !S390 dependency from Kconfig dasd: fix sysfs cleanup in dasd_generic_remove s390/pci: fix hotplug module init s390/pci: cleanup clp page allocation s390/pci: cleanup clp inline assembly s390/perf: cpum_cf: fallback to software sampling events s390/mm: provide PAGE_SHARED define ...
| * s390/time: rename tod clock access functionsHeiko Carstens2013-02-141-1/+1
| | | | | | | | | | | | | | | | Fix name clash with some common code device drivers and add "tod" to all tod clock access function names. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | cputime: Safely read cputime of full dynticks CPUsFrederic Weisbecker2013-01-271-3/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | While remotely reading the cputime of a task running in a full dynticks CPU, the values stored in utime/stime fields of struct task_struct may be stale. Its values may be those of the last kernel <-> user transition time snapshot and we need to add the tickless time spent since this snapshot. To fix this, flush the cputime of the dynticks CPUs on kernel <-> user transition and record the time / context where we did this. Then on top of this snapshot and the current time, perform the fixup on the reader side from task_times() accessors. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> [fixed kvm module related build errors] Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
* vtime: Warn if irqs aren't disabled on system time accounting APIsFrederic Weisbecker2012-11-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | System time accounting APIs such as vtime_account_system() and vtime_account_idle() need to be irqsafe. Current callers include irq entry, exit and kvm, all of which have been checked against that requirement. Now it's better to grow that with an automatic check in case we have further callers or we missed something. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
* vtime: Explicitly account pending user time on process tickFrederic Weisbecker2012-11-191-1/+6
| | | | | | | | | | | | | | | | | | | | | All vtime implementations just flush the user time on process tick. Consolidate that in generic code by calling a user time accounting helper. This avoids an indirect call in ia64 and prepare to also consolidate vtime context switch code. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
* vtime: Remove the underscore prefix invasionFrederic Weisbecker2012-11-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | Prepending irq-unsafe vtime APIs with underscores was actually a bad idea as the result is a big mess in the API namespace that is even waiting to be further extended. Also these helpers are always called from irq safe callers except kvm. Just provide a vtime_account_system_irqsafe() for this specific case so that we can remove the underscore prefix on other vtime functions. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
* vtime: Make vtime_account_system() irqsafeFrederic Weisbecker2012-10-291-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | vtime_account_system() currently has only one caller with vtime_account() which is irq safe. Now we are going to call it from other places like kvm where irqs are not always disabled by the time we account the cputime. So let's make it irqsafe. The arch implementation part is now prefixed with "__". vtime_account_idle() arch implementation is prefixed accordingly to stay consistent. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-10-011-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The main new feature is machine support for System zEC12 including transactional memory, runtime instrumentation, support for scm block devices via eadm subchannels, and support for CEX4 crypto cards. In addition there are some nice improvements: bpf jit compiler, arch backend for cmpxchg_double, relative exception table entries, dasd partition detection independent from the dasd driver ioctls, and cpu cache information in /proc/cpuinfo and /sys/device/cpu. And last but not least a series of cleanup patches from Heiko." Fix up trivial add-add conflict in arch/s390/Kconfig due to commit b952741c8079 ("cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING") * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (76 commits) s390: update defconfig s390/jump label,nss: let shared kernel support depend on !JUMP_LABEL s390/disassembler: fix decoding of risblg instruction s390/bpf,jit: add support for BPF_S_ANC_ALU_XOR_X instruction s390/traps: move call to print_modules() out of show_regs() s390/mm: mark free_initrd_mem() as __init s390/dasd: check count address during online setting drivers/s390/char/monreader.c: fix error return code s390/cmpxchg,percpu: implement cmpxchg_double() s390/percpu: implement this_cpu_add_return() s390/percpu: implement this_cpu_xchg() s390/kexec: remove CONFIG_KEXEC s390/irq: use designated initializers for irq class array s390: add uninitialized_var() to suppress false positive compiler warnings s390/crashdump: move fill_cpu_elf_notes() prototype to header file s390/process: add missing header include s390/ptrace: add missing ifdef s390/ipl,decrompressor: disable branch profiling s390/perf_events: compile only for CONFIG_64BIT s390/tape: remove even more tape block leftovers ...
| * s390/cpu hotplug: mask out CPU_TASKS_FROZEN in cu hotplug notifiersHeiko Carstens2012-09-261-2/+1
| | | | | | | | | | | | | | | | | | Unify all our cpu hotplug notifiers to mask out the CPU_TASKS_FROZEN bit, so we don't have to add all the *_FROZEN variant cases to the notifiers. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | cputime: Use a proper subsystem naming for vtime related APIsFrederic Weisbecker2012-09-251-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a naming based on vtime as a prefix for virtual based cputime accounting APIs: - account_system_vtime() -> vtime_account() - account_switch_vtime() -> vtime_task_switch() It makes it easier to allow for further declension such as vtime_account_system(), vtime_account_idle(), ... if we want to find out the context we account to from generic code. This also make it better to know on which subsystem these APIs refer to. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
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