From 93dd49d0028c66be9f0404d23dd6817b876cc6dc Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 10 Jun 2016 10:40:06 +0200 Subject: s390/oprofile: remove hardware sampler support Remove hardware sampler support from oprofile module. The oprofile user space utilty has been switched to use the kernel perf interface, for which we also provide hardware sampling support. In addition the hardware sampling support is also slightly broken: it supports only 16 bits for the pid and therefore would generate wrong results on machines which have a pid >64k. Also the pt_regs structure which was passed to oprofile common code cannot necessarily be used to generate sane backtraces, since the task(s) in question may run while the samples are fed to oprofile. So the result would be more or less random. However given that the only user space tools switched to the perf interface already four years ago the hardware sampler code seems to be unused code, and therefore it should be reasonable to remove it. The timer based oprofile support continues to work. Signed-off-by: Heiko Carstens Acked-by: Andreas Arnez Acked-by: Andreas Krebbel Acked-by: Robert Richter Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- Documentation/kernel-parameters.txt | 2 -- 1 file changed, 2 deletions(-) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c958d1c..68b0c022861a 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2788,8 +2788,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. timer: [X86] Force use of architectural NMI timer mode (see also oprofile.timer for generic hr timer mode) - [s390] Force legacy basic mode sampling - (report cpu_type "timer") oops=panic Always panic on oopses. Default is to just kill the process, but there is a small probability of -- cgit v1.2.3-55-g7522