linux/arch/s390
Thomas Richter 4141b6a5e9 s390/cpum_sf: Fix wrong page count in error message
When perf record -e SF_CYCLES_BASIC_DIAG runs with very high
frequency, the samples arrive faster than the perf process can
save them to file. Eventually, for longer running processes, this
leads to the siutation where the trace buffers allocated by perf
slowly fills up. At one point the auxiliary trace buffer is full
and  the CPU Measurement sampling facility is turned off. Furthermore
a warning is printed to the kernel log buffer:

cpum_sf: The AUX buffer with 0 pages for the diagnostic-sampling
	mode is full

The number of allocated pages for the auxiliary trace buffer is shown
as zero pages. That is wrong.

Fix this by saving the number of allocated pages before entering the
work loop in the interrupt handler. When the interrupt handler processes
the samples, it may detect the buffer full condition and stop sampling,
reducing the buffer size to zero.
Print the correct value in the error message:

cpum_sf: The AUX buffer with 256 pages for the diagnostic-sampling
	mode is full

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-03-25 12:39:37 +01:00
..
appldata s390: Replace zero-length array with flexible-array member 2020-02-27 16:02:21 +01:00
boot s390/arch: install kernels with their proper version ID 2020-02-19 17:27:24 +01:00
configs s390/config: do not select VIRTIO_CONSOLE via Kconfig 2020-03-11 14:18:44 +01:00
crypto s390/crypto: explicitly memzero stack key material in aes_s390.c 2020-02-27 16:02:21 +01:00
hypfs fs_parse: fold fs_parameter_desc/fs_parameter_spec 2020-02-07 14:48:37 -05:00
include s390/pci: Improve handling of unset UID 2020-03-23 13:41:55 +01:00
kernel s390/cpum_sf: Fix wrong page count in error message 2020-03-25 12:39:37 +01:00
kvm KVM: s390: Fixes and cleanups for 5.6 2020-02-05 16:15:05 +01:00
lib s390/test_unwind: fix spelling mistake "reqister" -> "register" 2019-12-11 19:53:23 +01:00
mm s390: remove broken hibernate / power management support 2020-03-23 13:41:55 +01:00
net s390/bpf: Remove JITed image size limitations 2019-11-18 19:51:16 -08:00
numa s390/mm: remove fake numa support 2020-02-27 16:02:21 +01:00
oprofile s390/unwind: introduce stack unwind API 2019-05-02 13:54:11 +02:00
pci s390/pci: Improve handling of unset UID 2020-03-23 13:41:55 +01:00
purgatory s390/purgatory: do not build purgatory with kcov, kasan and friends 2019-12-18 23:29:26 +01:00
scripts s390/build: use size command to perform empty .bss check 2019-08-08 14:36:53 +02:00
tools kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kbuild s390/kexec_file: Add purgatory 2018-04-16 09:10:22 +02:00
Kconfig s390: remove broken hibernate / power management support 2020-03-23 13:41:55 +01:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile s390: adjust -mpacked-stack support check for clang 10 2020-01-22 13:05:35 +01:00