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author | Vladimir Mezentsev <vladimir.mezentsev@oracle.com> | 2022-06-14 14:16:24 -0700 |
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committer | Vladimir Mezentsev <vladimir.mezentsev@oracle.com> | 2022-06-14 14:16:24 -0700 |
commit | a675e77e55759bad4501cbaaba36fa18dad2339d (patch) | |
tree | 3566c37a3f6079558b7afc931f0e906140a3ea5c /gprofng | |
parent | 08328cfbafcebac5dac058e2d568d9b2fd3ee478 (diff) | |
download | gdb-a675e77e55759bad4501cbaaba36fa18dad2339d.zip gdb-a675e77e55759bad4501cbaaba36fa18dad2339d.tar.gz gdb-a675e77e55759bad4501cbaaba36fa18dad2339d.tar.bz2 |
gprofng docs: provide help for <rate> == <interval>
The help message from 'gprofng collect app -h', in
the section on <rate> == <interval>, had a dangling
reference to a non-existent manpage. Provide basic
info, including reasons for caution.
Diffstat (limited to 'gprofng')
-rw-r--r-- | gprofng/common/hwctable.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/gprofng/common/hwctable.c b/gprofng/common/hwctable.c index bc441e1..a1422b6 100644 --- a/gprofng/common/hwctable.c +++ b/gprofng/common/hwctable.c @@ -5091,8 +5091,24 @@ hwc_usage_internal (int forKernel, FILE *f_usage, const char *cmd, const char *d fprintf (f_usage, GTXT (" `lo' per-thread maximum rate of ~10 samples/second\n")); fprintf (f_usage, GTXT (" `on' per-thread maximum rate of ~100 samples/second\n")); fprintf (f_usage, GTXT (" `hi' per-thread maximum rate of ~1000 samples/second\n\n")); - fprintf (f_usage, GTXT (" <rate> == <interval>\n")); - fprintf (f_usage, GTXT (" event interval; see collect (1) for details\n\n")); + fprintf (f_usage, GTXT (" <rate> == <interval>\n" + " Fixed event interval value to trigger a sample.\n" + " Smaller intervals imply more frequent samples.\n" + " Example: when counting cycles on a 2 GHz processor,\n" + " an interval of 2,000,003 implies ~1000 samples/sec\n" + "\n" + " Use this feature with caution, because:\n" + " (1) Frequent sampling increases overhead and may disturb \n" + " other applications on your system.\n" + " (2) Event counts vary dramatically depending on the event \n" + " and depending on the application.\n" + " (3) A fixed event interval disables any other gprofng\n" + " internal mechanisms that may limit event rates.\n" + "\n" + " Guidelines: Aim at <1000 events per second. Start by \n" + " collecting with the 'hi' option; in the experiment overview,\n" + " notice how many events are recorded per second; divide by\n" + " 1000, and use that as your starting point.\n\n")); fprintf (f_usage, GTXT (" A comma ',' followed immediately by white space may be omitted.\n\n")); } |