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| author | Zqiang <qiang.zhang@linux.dev> | 2026-07-23 18:04:30 +0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2026-07-30 11:21:14 -0700 |
| commit | df0ecbc497de851891847260f45805ca6ccb393f (patch) | |
| tree | 8f8b5820a05160fa7b292a3b1746a08c19125c70 /tools/lib/python | |
| parent | 27d73e81195b395270117ff77c47be2ed9b09b12 (diff) | |
| download | linux-df0ecbc497de851891847260f45805ca6ccb393f.tar.gz linux-df0ecbc497de851891847260f45805ca6ccb393f.zip | |
rcu: Reduce stack usage in show_rcu_gp_kthreads()
When CONFIG_KASAN=y and CONFIG_KASAN_STACK=y builds, the
show_rcu_gp_kthreads() exceeds the 1024-byte frame-size limit:
make kernel/rcu/tree.o KCFLAGS="-fstack-usage"
DESCEND objtool
DESCEND bpf/resolve_btfids
INSTALL libsubcmd_headers
CC kernel/rcu/tree.o
In file included from kernel/rcu/tree.c:4998:
kernel/rcu/tree_stall.h: In function 'show_rcu_gp_kthreads':
kernel/rcu/tree_stall.h:994:1: warning: the frame size of 1656 bytes is larger than 1024 bytes [-Wframe-larger-than=]
grep show_rcu kernel/rcu/tree.su
tree_nocb.h:1622:13:show_rcu_nocb_state 896 dynamic,bounded
tree_stall.h:933:6:show_rcu_gp_kthreads 1784 dynamic,bounded
tree_stall.h:1102:13:sysrq_show_rcu 16 static
Wrap the pr_info() into two noinline_for_stack helpers function:
show_rcu_state() print rcu_state status, and show_rcu_node()
print single rcu_node status.
After apply this change:
grep show_rcu kernel/rcu/tree.su
tree_stall.h:955:22:show_rcu_node 696 dynamic,bounded
tree_stall.h:930:22:show_rcu_state 872 dynamic,bounded
tree_nocb.h:1622:13:show_rcu_nocb_state 896 dynamic,bounded
tree_stall.h:972:6:show_rcu_gp_kthreads 544 static
tree_stall.h:1113:13:sysrq_show_rcu 16 static
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'tools/lib/python')
0 files changed, 0 insertions, 0 deletions