diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-02-11 08:10:18 +0100 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-02-25 12:07:01 -0500 |
| commit | bc82c38a6933aab308387d4aca47e0a05de7b553 (patch) | |
| tree | 3e3b025d70d013e4530f70f22861d736bd804bee /kernel | |
| parent | b61edd57740de5895f44f2ea417b164d9e1708bb (diff) | |
tracing: Uninline trace_trigger_soft_disabled() partly
On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline
keyword is not honored and trace_trigger_soft_disabled() appears
approx 50 times in vmlinux.
Adding -Winline to the build, the following message appears:
./include/linux/trace_events.h:712:1: error: inlining failed in call to 'trace_trigger_soft_disabled': call is unlikely and code size would grow [-Werror=inline]
That function is rather big for an inlined function:
c003df60 <trace_trigger_soft_disabled>:
c003df60: 94 21 ff f0 stwu r1,-16(r1)
c003df64: 7c 08 02 a6 mflr r0
c003df68: 90 01 00 14 stw r0,20(r1)
c003df6c: bf c1 00 08 stmw r30,8(r1)
c003df70: 83 e3 00 24 lwz r31,36(r3)
c003df74: 73 e9 01 00 andi. r9,r31,256
c003df78: 41 82 00 10 beq c003df88 <trace_trigger_soft_disabled+0x28>
c003df7c: 38 60 00 00 li r3,0
c003df80: 39 61 00 10 addi r11,r1,16
c003df84: 4b fd 60 ac b c0014030 <_rest32gpr_30_x>
c003df88: 73 e9 00 80 andi. r9,r31,128
c003df8c: 7c 7e 1b 78 mr r30,r3
c003df90: 41 a2 00 14 beq c003dfa4 <trace_trigger_soft_disabled+0x44>
c003df94: 38 c0 00 00 li r6,0
c003df98: 38 a0 00 00 li r5,0
c003df9c: 38 80 00 00 li r4,0
c003dfa0: 48 05 c5 f1 bl c009a590 <event_triggers_call>
c003dfa4: 73 e9 00 40 andi. r9,r31,64
c003dfa8: 40 82 00 28 bne c003dfd0 <trace_trigger_soft_disabled+0x70>
c003dfac: 73 ff 02 00 andi. r31,r31,512
c003dfb0: 41 82 ff cc beq c003df7c <trace_trigger_soft_disabled+0x1c>
c003dfb4: 80 01 00 14 lwz r0,20(r1)
c003dfb8: 83 e1 00 0c lwz r31,12(r1)
c003dfbc: 7f c3 f3 78 mr r3,r30
c003dfc0: 83 c1 00 08 lwz r30,8(r1)
c003dfc4: 7c 08 03 a6 mtlr r0
c003dfc8: 38 21 00 10 addi r1,r1,16
c003dfcc: 48 05 6f 6c b c0094f38 <trace_event_ignore_this_pid>
c003dfd0: 38 60 00 01 li r3,1
c003dfd4: 4b ff ff ac b c003df80 <trace_trigger_soft_disabled+0x20>
However it is located in a hot path so inlining it is important.
But forcing inlining of the entire function by using __always_inline
leads to increasing the text size by approx 20 kbytes.
Instead, split the fonction in two parts, one part with the likely
fast path, flagged __always_inline, and a second part out of line.
With this change, on a powerpc32 with CONFIG_CC_OPTIMISE_FOR_SIZE
vmlinux text increases by only 1,4 kbytes, which is partly
compensated by a decrease of vmlinux data by 7 kbytes.
On ppc64_defconfig which has CONFIG_CC_OPTIMISE_FOR_SPEED, this
change reduces vmlinux text by more than 30 kbytes.
Link: https://lkml.kernel.org/r/69ce0986a52d026d381d612801d978aa4f977460.1644563295.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_events_trigger.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index efe563140f27..7eb9d04f1c2e 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -84,6 +84,20 @@ event_triggers_call(struct trace_event_file *file, } EXPORT_SYMBOL_GPL(event_triggers_call); +bool __trace_trigger_soft_disabled(struct trace_event_file *file) +{ + unsigned long eflags = file->flags; + + if (eflags & EVENT_FILE_FL_TRIGGER_MODE) + event_triggers_call(file, NULL, NULL, NULL); + if (eflags & EVENT_FILE_FL_SOFT_DISABLED) + return true; + if (eflags & EVENT_FILE_FL_PID_FILTER) + return trace_event_ignore_this_pid(file); + return false; +} +EXPORT_SYMBOL_GPL(__trace_trigger_soft_disabled); + /** * event_triggers_post_call - Call 'post_triggers' for a trace event * @file: The trace_event_file associated with the event |