From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- scripts/stackdelta | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100755 scripts/stackdelta (limited to 'scripts/stackdelta') diff --git a/scripts/stackdelta b/scripts/stackdelta new file mode 100755 index 000000000..44d2dfd62 --- /dev/null +++ b/scripts/stackdelta @@ -0,0 +1,60 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 + +# Read two files produced by the stackusage script, and show the +# delta between them. +# +# Currently, only shows changes for functions listed in both files. We +# could add an option to show also functions which have vanished or +# appeared (which would often be due to gcc making other inlining +# decisions). +# +# Another possible option would be a minimum absolute value for the +# delta. +# +# A third possibility is for sorting by delta, but that can be +# achieved by piping to sort -k5,5g. + +sub read_stack_usage_file { + my %su; + my $f = shift; + open(my $fh, '<', $f) + or die "cannot open $f: $!"; + while (<$fh>) { + chomp; + my ($file, $func, $size, $type) = split; + # Old versions of gcc (at least 4.7) have an annoying quirk in + # that a (static) function whose name has been changed into + # for example ext4_find_unwritten_pgoff.isra.11 will show up + # in the .su file with a name of just "11". Since such a + # numeric suffix is likely to change across different + # commits/compilers/.configs or whatever else we're trying to + # tweak, we can't really track those functions, so we just + # silently skip them. + # + # Newer gcc (at least 5.0) report the full name, so again, + # since the suffix is likely to change, we strip it. + next if $func =~ m/^[0-9]+$/; + $func =~ s/\..*$//; + # Line numbers are likely to change; strip those. + $file =~ s/:[0-9]+$//; + $su{"${file}\t${func}"} = {size => $size, type => $type}; + } + close($fh); + return \%su; +} + +@ARGV == 2 + or die "usage: $0 "; + +my $old = read_stack_usage_file($ARGV[0]); +my $new = read_stack_usage_file($ARGV[1]); +my @common = sort grep {exists $new->{$_}} keys %$old; +for (@common) { + my $x = $old->{$_}{size}; + my $y = $new->{$_}{size}; + my $delta = $y - $x; + if ($delta) { + printf "%s\t%d\t%d\t%+d\n", $_, $x, $y, $delta; + } +} -- cgit v1.3.1