* [PATCH v2] f2fs: optimize trace_f2fs_write_checkpoint with enums
[not found] <no>
@ 2025-11-28 3:23 ` YH Lin
2025-12-02 18:10 ` [f2fs-dev] " patchwork-bot+f2fs
0 siblings, 1 reply; 2+ messages in thread
From: YH Lin @ 2025-11-28 3:23 UTC (permalink / raw)
To: yes
Cc: YH Lin, Jaegeuk Kim, Chao Yu, Steven Rostedt, Masami Hiramatsu,
Mathieu Desnoyers, linux-f2fs-devel, linux-kernel,
linux-trace-kernel
This patch optimizes the tracepoint by replacing these hardcoded strings
with a new enumeration f2fs_cp_phase.
1.Defines enum f2fs_cp_phase with values for each checkpoint phase.
2.Updates trace_f2fs_write_checkpoint to accept a u16 phase argument
instead of a string pointer.
3.Uses __print_symbolic in TP_printk to convert the enum values
back to their corresponding strings for human-readable trace output.
This change reduces the storage overhead for each trace event
by replacing a variable-length string with a 2-byte integer,
while maintaining the same readable output in ftrace.
Signed-off-by: YH Lin <yhli@google.com>
V2:
- Relocate enum f2fs_cp_phase from include/trace/events/f2fs.h to fs/f2fs/f2fs.h,
as requested by Chao Yu for better structure cleanup.
---
fs/f2fs/checkpoint.c | 6 +++---
fs/f2fs/f2fs.h | 6 ++++++
include/trace/events/f2fs.h | 19 ++++++++++++++-----
3 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index bbe07e3a6c75..b04f82fdd143 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1673,7 +1673,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
goto out;
}
- trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "start block_ops");
+ trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, CP_PHASE_START_BLOCK_OPS);
err = block_operations(sbi);
if (err)
@@ -1681,7 +1681,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
stat_cp_time(cpc, CP_TIME_OP_LOCK);
- trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish block_ops");
+ trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, CP_PHASE_FINISH_BLOCK_OPS);
f2fs_flush_merged_writes(sbi);
@@ -1747,7 +1747,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
/* update CP_TIME to trigger checkpoint periodically */
f2fs_update_time(sbi, CP_TIME);
- trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint");
+ trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, CP_PHASE_FINISH_CHECKPOINT);
out:
if (cpc->reason != CP_RESIZE)
f2fs_up_write(&sbi->cp_global_sem);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 6f509d88c596..a995103af735 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -313,6 +313,12 @@ struct cp_control {
struct cp_stats stats;
};
+enum f2fs_cp_phase {
+ CP_PHASE_START_BLOCK_OPS,
+ CP_PHASE_FINISH_BLOCK_OPS,
+ CP_PHASE_FINISH_CHECKPOINT,
+};
+
/*
* indicate meta/data type
*/
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index e00611ead024..df4017dcc701 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -50,6 +50,9 @@ TRACE_DEFINE_ENUM(CP_PAUSE);
TRACE_DEFINE_ENUM(CP_RESIZE);
TRACE_DEFINE_ENUM(EX_READ);
TRACE_DEFINE_ENUM(EX_BLOCK_AGE);
+TRACE_DEFINE_ENUM(CP_PHASE_START_BLOCK_OPS);
+TRACE_DEFINE_ENUM(CP_PHASE_FINISH_BLOCK_OPS);
+TRACE_DEFINE_ENUM(CP_PHASE_FINISH_CHECKPOINT);
#define show_block_type(type) \
__print_symbolic(type, \
@@ -175,6 +178,12 @@ TRACE_DEFINE_ENUM(EX_BLOCK_AGE);
#define S_ALL_PERM (S_ISUID | S_ISGID | S_ISVTX | \
S_IRWXU | S_IRWXG | S_IRWXO)
+#define show_cp_phase(phase) \
+ __print_symbolic(phase, \
+ { CP_PHASE_START_BLOCK_OPS, "start block_ops" }, \
+ { CP_PHASE_FINISH_BLOCK_OPS, "finish block_ops" }, \
+ { CP_PHASE_FINISH_CHECKPOINT, "finish checkpoint" })
+
struct f2fs_sb_info;
struct f2fs_io_info;
struct extent_info;
@@ -1573,26 +1582,26 @@ TRACE_EVENT(f2fs_readpages,
TRACE_EVENT(f2fs_write_checkpoint,
- TP_PROTO(struct super_block *sb, int reason, const char *msg),
+ TP_PROTO(struct super_block *sb, int reason, u16 phase),
- TP_ARGS(sb, reason, msg),
+ TP_ARGS(sb, reason, phase),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(int, reason)
- __string(dest_msg, msg)
+ __field(u16, phase)
),
TP_fast_assign(
__entry->dev = sb->s_dev;
__entry->reason = reason;
- __assign_str(dest_msg);
+ __entry->phase = phase;
),
TP_printk("dev = (%d,%d), checkpoint for %s, state = %s",
show_dev(__entry->dev),
show_cpreason(__entry->reason),
- __get_str(dest_msg))
+ show_cp_phase(__entry->phase))
);
DECLARE_EVENT_CLASS(f2fs_discard,
--
2.52.0.487.g5c8c507ade-goog
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