emacs-27 7722b51: Another improvement in documentation of "memory" profiler

[Eli Zaretskii]

branch: emacs-27
commit 7722b510aae119162a20cfc67d3057152835a4ba
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Another improvement in documentation of "memory" profiler
    
    * lisp/profiler.el (profiler-start): Fix the doc string to better
    explain what is "memory" profiler.
---
 lisp/profiler.el | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lisp/profiler.el b/lisp/profiler.el
index eb0e2c9..7cdd351 100644
--- a/lisp/profiler.el
+++ b/lisp/profiler.el
@@ -812,8 +812,12 @@ below entry at point."
 (defun profiler-start (mode)
   "Start/restart profilers.
 MODE can be one of `cpu', `mem', or `cpu+mem'.
-If MODE is `cpu' or `cpu+mem', time-based profiler will be started.
-Also, if MODE is `mem' or `cpu+mem', then memory profiler will be started."
+If MODE is `cpu' or `cpu+mem', start the time-based profiler,
+   whereby CPU is sampled periodically using the SIGPROF signal.
+If MODE is `mem' or `cpu+mem', start profiler that samples CPU
+   whenever memory-allocation functions are called -- this is useful
+   if SIGPROF is not supported, or is unreliable, or is not sampling
+   at a high enough frequency."
   (interactive
    (list (if (not (fboundp 'profiler-cpu-start)) 'mem
            (intern (completing-read "Mode (default cpu): "