diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2023-02-15 12:33:28 -0500 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-02-15 12:33:28 -0500 |
commit | 33436335e93a1788a58443fc99c5ab320ce4b9d9 (patch) | |
tree | d92f88768c8dbd00f8b65164f47a8a091768b95a /scripts/tracing/ftrace-bisect.sh | |
parent | 27b025ebb0f6092d5c0a88de2ab73545bc1c496e (diff) | |
parent | c39cea6f38eefe356d64d0bc1e1f2267e282cdd3 (diff) |
Merge tag 'kvm-riscv-6.3-1' of https://github.com/kvm-riscv/linux into HEAD
KVM/riscv changes for 6.3
- Fix wrong usage of PGDIR_SIZE to check page sizes
- Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect()
- Redirect illegal instruction traps to guest
- SBI PMU support for guest
Diffstat (limited to 'scripts/tracing/ftrace-bisect.sh')
-rwxr-xr-x | scripts/tracing/ftrace-bisect.sh | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/scripts/tracing/ftrace-bisect.sh b/scripts/tracing/ftrace-bisect.sh index 926701162bc8..bb4f59262bbe 100755 --- a/scripts/tracing/ftrace-bisect.sh +++ b/scripts/tracing/ftrace-bisect.sh @@ -12,7 +12,7 @@ # (note, if this is a problem with function_graph tracing, then simply # replace "function" with "function_graph" in the following steps). # -# # cd /sys/kernel/debug/tracing +# # cd /sys/kernel/tracing # # echo schedule > set_ftrace_filter # # echo function > current_tracer # @@ -20,22 +20,40 @@ # # # echo nop > current_tracer # -# # cat available_filter_functions > ~/full-file +# Starting with v5.1 this can be done with numbers, making it much faster: +# +# The old (slow) way, for kernels before v5.1. +# +# [old-way] # cat available_filter_functions > ~/full-file +# +# [old-way] *** Note *** this process will take several minutes to update the +# [old-way] filters. Setting multiple functions is an O(n^2) operation, and we +# [old-way] are dealing with thousands of functions. So go have coffee, talk +# [old-way] with your coworkers, read facebook. And eventually, this operation +# [old-way] will end. +# +# The new way (using numbers) is an O(n) operation, and usually takes less than a second. +# +# seq `wc -l available_filter_functions | cut -d' ' -f1` > ~/full-file +# +# This will create a sequence of numbers that match the functions in +# available_filter_functions, and when echoing in a number into the +# set_ftrace_filter file, it will enable the corresponding function in +# O(1) time. Making enabling all functions O(n) where n is the number of +# functions to enable. +# +# For either the new or old way, the rest of the operations remain the same. +# # # ftrace-bisect ~/full-file ~/test-file ~/non-test-file # # cat ~/test-file > set_ftrace_filter # -# *** Note *** this will take several minutes. Setting multiple functions is -# an O(n^2) operation, and we are dealing with thousands of functions. So go -# have coffee, talk with your coworkers, read facebook. And eventually, this -# operation will end. -# # # echo function > current_tracer # # If it crashes, we know that ~/test-file has a bad function. # # Reboot back to test kernel. # -# # cd /sys/kernel/debug/tracing +# # cd /sys/kernel/tracing # # mv ~/test-file ~/full-file # # If it didn't crash. |