linux_dsm_epyc7002/arch/s390/kernel
Thomas Richter 39d4a501a9 s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits
Function perf_event_ever_overflow() and perf_event_account_interrupt()
are called every time samples are processed by the interrupt handler.
However function perf_event_account_interrupt() has checks to avoid being
flooded with interrupts (more then 1000 samples are received per
task_tick).  Samples are then dropped and a PERF_RECORD_THROTTLED is
added to the perf data. The perf subsystem limit calculation is:

    maximum sample frequency := 100000 --> 1 samples per 10 us
    task_tick = 10ms = 10000us --> 1000 samples per task_tick

The work flow is

measurement_alert() uses SDBT head and each SBDT points to 511
 SDB pages, each with 126 sample entries. After processing 8 SBDs
 and for each valid sample calling:

     perf_event_overflow()
       perf_event_account_interrupts()

there is a considerable amount of samples being dropped, especially when
the sample frequency is very high and near the 100000 limit.

To avoid the high amount of samples being dropped near the end of a
task_tick time frame, increment the sampling interval in case of
dropped events. The CPU Measurement sampling facility on the s390
supports only intervals, specifiing how many CPU cycles have to be
executed before a sample is generated. Increase the interval when the
samples being generated hit the task_tick limit.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11 19:53:23 +01:00
..
syscalls s390: wire up clone3 system call 2019-07-23 10:45:53 +02:00
vdso64 s390/vdso: fix getcpu 2019-11-30 10:52:44 +01:00
.gitignore s390: add various .gitignore files. 2012-05-16 14:42:41 +02:00
alternative.c s390: add automatic detection of the spectre defense 2018-03-28 08:38:24 +02:00
asm-offsets.c s390/vdso: fix getcpu 2019-11-30 10:52:44 +01:00
audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
audit.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
base.S s390/base: remove unused s390_base_mcck_handler 2019-09-03 13:53:56 +02:00
cache.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_linux.c s390: use generic UID16 implementation 2019-01-18 09:33:18 +01:00
compat_linux.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_ptrace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_signal.c signal: Remove task parameter from force_sig 2019-05-27 09:36:28 -05:00
cpcmd.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crash_dump.c memblock: memblock_phys_alloc(): don't panic 2019-03-12 10:04:01 -07:00
debug.c docs: s390: unify and update s390dbf kdocs at debug.c 2019-07-05 13:42:22 +02:00
diag.c s390/kernel: introduce .dma sections 2019-04-29 10:47:10 +02:00
dis.c s390/disassembler: don't hide instruction addresses 2019-11-12 11:24:10 +01:00
dumpstack.c s390/unwind: add stack pointer alignment sanity checks 2019-11-30 10:52:48 +01:00
early_printk.c s390/sclp: avoid using strncmp with hardcoded length 2019-08-29 15:34:58 +02:00
early.c s390/early: move access registers setup in C code 2019-11-20 12:58:13 +01:00
ebcdic.c s390: ebcdic: convert comments to UTF-8 2018-08-23 18:48:43 -07:00
entry.h PM: hibernate: powerpc: Expose pfn_is_nosave() prototype 2019-06-14 10:48:56 +02:00
entry.S s390: enforce CONFIG_SMP 2019-06-07 10:09:37 +02:00
fpu.c s390: correct some inline assembly constraints 2019-04-17 10:40:57 +02:00
ftrace.c s390/ftrace: use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 2019-05-02 13:54:11 +02:00
guarded_storage.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
head64.S s390/head64: correct init_task stack setup 2019-11-30 10:52:45 +01:00
idle.c s390/idle: fix cpu idle time calculation 2019-10-31 17:26:48 +01:00
ima_arch.c s390/kexec_file: Disable kexec_load when IPLed secure 2019-04-29 10:44:03 +02:00
ipl_vmparm.c s390/ipl: provide uapi header for list directed IPL 2019-04-26 12:34:05 +02:00
ipl.c s390/protvirt: avoid memory sharing for diag 308 set/store 2019-08-06 13:58:34 +02:00
irq.c s390/unwind: introduce stack unwind API 2019-05-02 13:54:11 +02:00
jump_label.c s390/jump_label: remove unused structure definition 2019-06-07 10:10:10 +02:00
kdebugfs.c s390: no need to check return value of debugfs_create functions 2019-01-28 15:58:55 +01:00
kexec_elf.c kexec: Fix file verification on S390 2019-09-10 13:27:51 +01:00
kexec_image.c kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE 2019-08-19 21:54:15 -07:00
kprobes.c s390/kernel: introduce .dma sections 2019-04-29 10:47:10 +02:00
lgr.c s390: kernel: add SPDX identifiers to the remaining files 2017-11-24 15:37:12 +01:00
machine_kexec_file.c Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
machine_kexec_reloc.c s390/kaslr: add support for R_390_GLOB_DAT relocation type 2019-10-22 17:55:51 +02:00
machine_kexec.c s390/kaslr: store KASLR offset for early dumps 2019-11-30 10:52:45 +01:00
Makefile s390: remove compat vdso code 2019-12-01 12:48:49 +01:00
mcount.S s390/ftrace: use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 2019-05-02 13:54:11 +02:00
module.c s390/module: avoid using strncmp with hardcoded length 2019-08-29 15:34:57 +02:00
nmi.c s390: simplify disabled_wait 2019-05-02 13:54:11 +02:00
nospec-branch.c s390 updates for the 5.2 merge window 2019-05-06 16:42:54 -07:00
nospec-sysfs.c s390: Convert IS_ENABLED uses to __is_defined 2019-04-11 13:36:53 +02:00
os_info.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
perf_cpum_cf_common.c s390/cpum_cf: move common functions into a separate file 2019-02-22 09:19:55 +01:00
perf_cpum_cf_diag.c s390/cpumf: Adjust registration of s390 PMU device drivers 2019-11-20 17:16:01 +01:00
perf_cpum_cf_events.c s390/cpumf: Add extended counter set definitions for model 8561 and 8562 2019-07-11 20:40:01 +02:00
perf_cpum_cf.c s390/cpumf: Adjust registration of s390 PMU device drivers 2019-11-20 17:16:01 +01:00
perf_cpum_sf.c s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits 2019-12-11 19:53:23 +01:00
perf_event.c s390: add error handling to perf_callchain_kernel 2019-10-31 17:20:54 +01:00
perf_regs.c s390/perf: fix gcc 8 array-bounds warning 2018-07-02 11:24:54 +02:00
pgm_check.S s390/kernel: convert SYSCALL and PGM_CHECK handlers to .quad 2019-04-29 10:47:10 +02:00
process.c s390/process: avoid custom stack unwinding in get_wchan 2019-10-31 17:20:53 +01:00
processor.c processor: get rid of cpu_relax_yield 2019-06-15 12:25:55 +02:00
ptrace.c seccomp: simplify secure_computing() 2019-10-10 14:55:24 -07:00
reipl.S s390: add missing ENDPROC statements to assembler functions 2019-05-02 13:54:11 +02:00
relocate_kernel.S s390: add missing ENDPROC statements to assembler functions 2019-05-02 13:54:11 +02:00
runtime_instr.c s390/runtime_instrumentation: re-add signum system call parameter 2018-02-05 07:34:50 +01:00
setup.c s390: avoid misusing CALL_ON_STACK for task stack setup 2019-11-30 10:52:45 +01:00
signal.c signal: Remove task parameter from force_sig 2019-05-27 09:36:28 -05:00
smp.c s390: avoid misusing CALL_ON_STACK for task stack setup 2019-11-30 10:52:45 +01:00
stacktrace.c s390/livepatch: Implement reliable stack tracing for the consistency model 2019-11-30 10:52:48 +01:00
sthyi.c s390/sthyi: Fix machine name validity indication 2018-10-15 12:17:00 +02:00
suspend.c s390: unify linker symbols usage 2018-02-27 08:05:23 +01:00
swsusp.S s390: enforce CONFIG_SMP 2019-06-07 10:09:37 +02:00
sys_s390.c s390: autogenerate compat syscall wrappers 2019-01-18 09:33:19 +01:00
sysinfo.c s390: no need to check return value of debugfs_create functions 2019-01-28 15:58:55 +01:00
time.c s390/time: remove monotonic_clock() 2019-10-31 17:20:52 +01:00
topology.c s390/topology: avoid firing events before kobjs are created 2019-09-23 23:27:52 +02:00
trace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
traps.c Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2019-07-08 21:48:15 -07:00
unwind_bc.c s390/unwind: add stack pointer alignment sanity checks 2019-11-30 10:52:48 +01:00
uprobes.c s390/uprobes: implement arch_uretprobe_is_alive() 2018-04-23 07:57:16 +02:00
vdso.c s390: remove compat vdso code 2019-12-01 12:48:49 +01:00
vmlinux.lds.S vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA 2019-11-04 15:57:41 +01:00
vtime.c sched/cputime: Rename vtime_account_system() to vtime_account_kernel() 2019-10-09 12:39:25 +02:00