Revert "PORTAGE_NICENESS: Consider autogroup scheduling"

This reverts commit a4d882964ee1931462f911d0c46a80e27e59fa48.
It triggered this regression:

# PORTAGE_NICENESS=20 emerge -av --depclean
OSError: [Errno 22] Invalid argument

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python-exec/python3.9/emerge", line 51, in <module>
    retval = emerge_main()
  File "/usr/lib/python3.9/site-packages/_emerge/main.py", line 1319, in emerge_main
    return run_action(emerge_config)
  File "/usr/lib/python3.9/site-packages/_emerge/actions.py", line 2999, in run_action
    apply_priorities(emerge_config.target_config.settings)
  File "/usr/lib/python3.9/site-packages/_emerge/actions.py", line 2635, in apply_priorities
    nice(settings)
  File "/usr/lib/python3.9/site-packages/_emerge/actions.py", line 2672, in nice
    out.eerror("%s\n" % str(e))
OSError: [Errno 22] Invalid argument

Bug: https://bugs.gentoo.org/777492#c4
Signed-off-by: Zac Medico <zmedico@gentoo.org>

2 files changed, 4 insertions, 42 deletions

diff --git a/lib/_emerge/actions.py b/lib/_emerge/actions.py
index bfb08ed6b..1946f49df 100644
--- a/lib/_emerge/actions.py
+++ b/lib/_emerge/actions.py
@@ -14,7 +14,6 @@ import textwrap
 import time
 import warnings
 from itertools import chain
-from pathlib import Path
 
 import portage
 portage.proxy.lazyimport.lazyimport(globals(),
@@ -2635,43 +2634,14 @@ def apply_priorities(settings):
 	nice(settings)
 
 def nice(settings):
-	nice_value: str = settings.get("PORTAGE_NICENESS", "0")
-
 	try:
-		os.nice(int(nice_value))
+		os.nice(int(settings.get("PORTAGE_NICENESS", "0")))
 	except (OSError, ValueError) as e:
 		out = portage.output.EOutput()
-		out.eerror(f"Failed to change nice value to {nice_value}")
+		out.eerror("Failed to change nice value to '%s'" % \
+			settings.get("PORTAGE_NICENESS", "0"))
 		out.eerror("%s\n" % str(e))
 
-	autogroup_file = Path("/proc/self/autogroup")
-	try:
-		f = autogroup_file.open("r+")
-	except EnvironmentError:
-		# Autogroup scheduling is not enabled on this system.
-		return
-
-	with f:
-		line = f.readline()
-		original_autogroup_nice_value = line.split(" ")[2]
-
-		# We need to restore the original nice value of the
-		# autogroup, as otherwise the session, e.g. the
-		# terminal where portage was executed in, would
-		# continue running with that value.
-		portage.atexit_register(
-			lambda value: autogroup_file.write_text(value),
-			original_autogroup_nice_value,
-		)
-
-		try:
-			f.write(nice_value)
-		except EnvironmentError as e:
-			out = portage.output.EOutput()
-			out.eerror(f"Failed to change autogroup's nice value to {nice_value}")
-			out.eerror("%s\n" % str(e))
-
-
 def ionice(settings):
 
 	ionice_cmd = settings.get("PORTAGE_IONICE_COMMAND")
diff --git a/man/make.conf.5 b/man/make.conf.5
index 18573b5e2..1c72109ad 100644
--- a/man/make.conf.5
+++ b/man/make.conf.5
@@ -1,4 +1,4 @@
-.TH "MAKE.CONF" "5" "Jun 2021" "Portage VERSION" "Portage"
+.TH "MAKE.CONF" "5" "May 2021" "Portage VERSION" "Portage"
 .SH "NAME"
 make.conf \- custom settings for Portage
 .SH "SYNOPSIS"
@@ -1031,14 +1031,6 @@ The value of this variable will be added to the current nice level that
 emerge is running at.  In other words, this will not set the nice level,
 it will increment it.  For more information about nice levels and what
 are acceptable ranges, see \fBnice\fR(1).
-.br
-If set and portage is run under Linux with autogroup scheduling (see
-\fBsched\fR(7)) enabled, then portage will set the nice value of its
-autogroup to PORTAGE_NICENESS. Upon exiting, portage will restore the
-original value. Note that if the function responsible for restoring the
-original value is not run, e.g., because portage's process was killed,
-then the autogroup will stay niced. In such a case, the value can be
-reset via corresponding autogroup pseudo\-file in /proc.
 .TP
 \fBPORTAGE_RO_DISTDIRS\fR = \fI[space delimited list of directories]\fR
 When a given file does not exist in \fBDISTDIR\fR, search for the file