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Revision 1.10 / (download) - annotate - [select for diffs], Mon Apr 1 22:49:04 2024 UTC (2 months ago) by jsg
Branch: MAIN
CVS Tags: HEAD
Changes since 1.9: +2 -2 lines
Diff to previous 1.9 (colored)
init var to fix missing symtab section path found by smatch, ok mpi@
Revision 1.9 / (download) - annotate - [select for diffs], Sat Mar 16 17:42:37 2024 UTC (2 months, 3 weeks ago) by cheloha
Branch: MAIN
Changes since 1.8: +136 -106 lines
Diff to previous 1.8 (colored)
btrace(8): cache ELF symbols in sorted array Currently, every kelf_snprintsym() call performs a linear search through the .symtab for a symbol matching the given PC. The search is expensive and seems to be a major source of dropped profiling events. Storing all STT_FUNC .symtab entries and their names in a sorted array cuts search time from O(n) to O(lg n). In practice, the faster lookups seem to dramatically reduce the profiling drop rate. With tweaks from mpi@. Thread: https://marc.info/?l=openbsd-tech&m=170830125132105&w=2 ok mpi@
Revision 1.8 / (download) - annotate - [select for diffs], Thu Mar 14 00:54:54 2024 UTC (2 months, 3 weeks ago) by cheloha
Branch: MAIN
Changes since 1.7: +105 -135 lines
Diff to previous 1.7 (colored)
Revert "btrace(8): cache ELF .symtab, .strtab entries in sorted array" "No it's not okay." mpi@
Revision 1.7 / (download) - annotate - [select for diffs], Tue Mar 12 17:22:24 2024 UTC (2 months, 3 weeks ago) by cheloha
Branch: MAIN
Changes since 1.6: +136 -106 lines
Diff to previous 1.6 (colored)
btrace(8): cache ELF .symtab, .strtab entries in sorted array Currently, every kelf_snprintsym() call performs a linear search through the .symtab for a matching symbol. The search is very costly and causes btrace(8) to drop a lot of profiling events. Storing the STT_FUNC .symtab entries and their corresponding .strtab entries in a sorted array cuts the lookup cost from O(n) to O(lg n). Lower overhead reduces the drop rate for profiling events. With tweaks from mpi@. Thread: https://marc.info/?l=openbsd-tech&m=170830125132105&w=2 probably ok mpi@
Revision 1.6 / (download) - annotate - [select for diffs], Fri Nov 10 18:56:21 2023 UTC (6 months, 4 weeks ago) by jasper
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE,
OPENBSD_7_5
Changes since 1.5: +1 -3 lines
Diff to previous 1.5 (colored)
zap some unused includes
Revision 1.5 / (download) - annotate - [select for diffs], Fri May 12 14:14:16 2023 UTC (12 months, 3 weeks ago) by claudio
Branch: MAIN
CVS Tags: OPENBSD_7_4_BASE,
OPENBSD_7_4
Changes since 1.4: +59 -46 lines
Diff to previous 1.4 (colored)
btrace(8) support to symbolize utrace addresses.
This only works for a single static binary where everything was compiled
with -fno-omit-frame-pointer since the stack unwinder requires the
frame-pointer.
A possible btrace script to capture performace of a single process is:
profile:hz:100 / pid == $1 / {
@[ustack] = count();
}
Then using btrace -p program uprofile.bt `pgrep program` will collect
the information for program.
This is far from perfect but should allow other people to play with this
and hopefully improve work.
OK mpi@
Revision 1.4 / (download) - annotate - [select for diffs], Wed Feb 10 00:34:57 2021 UTC (3 years, 3 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_7_3_BASE,
OPENBSD_7_3,
OPENBSD_7_2_BASE,
OPENBSD_7_2,
OPENBSD_7_1_BASE,
OPENBSD_7_1,
OPENBSD_7_0_BASE,
OPENBSD_7_0,
OPENBSD_6_9_BASE,
OPENBSD_6_9
Changes since 1.3: +2 -2 lines
Diff to previous 1.3 (colored)
cast large to reduce warning on 32-bit machines (an ELF type is printed with %ll)
Revision 1.3 / (download) - annotate - [select for diffs], Mon Dec 7 18:28:09 2020 UTC (3 years, 6 months ago) by bluhm
Branch: MAIN
Changes since 1.2: +12 -3 lines
Diff to previous 1.2 (colored)
In btrace(8) handle snprintf(3) errors correctly. If snprintf fails, buffer is unchanged; initialize it with empty string. snprintf may return negative value or the length that would have been written; check and calculate remaining size. snprintf writes size - 1 characters; pass buffer size as length. OK mpi@
Revision 1.2 / (download) - annotate - [select for diffs], Thu Aug 13 11:35:21 2020 UTC (3 years, 9 months ago) by mpi
Branch: MAIN
CVS Tags: OPENBSD_6_8_BASE,
OPENBSD_6_8
Changes since 1.1: +5 -7 lines
Diff to previous 1.1 (colored)
Be compatible with bpftrace(8)'s output when printing stack traces in maps. This allows us to use `stackcollapse-bpftrace.pl' from Brendan Gregg's FrameGraph without pre-processing outputs.
Revision 1.1 / (download) - annotate - [select for diffs], Tue Jan 21 16:24:55 2020 UTC (4 years, 4 months ago) by mpi
Branch: MAIN
CVS Tags: OPENBSD_6_7_BASE,
OPENBSD_6_7
Import a bug tracer, companion of dt(4), that speaks the bt(5) language. ok kettenis@, visa@, jasper@, deraadt@