[f2fs-dev] [PATCH] f2fs: optimize trace_f2fs_write_checkpoint with enums

2025-11-17 Thread YH Lin via Linux-f2fs-devel
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 
---
 fs/f2fs/checkpoint.c|  6 +++---
 include/trace/events/f2fs.h | 28 +++-
 2 files changed, 26 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/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index e00611ead024..a87aab397457 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -11,6 +11,15 @@
 #define show_dev(dev)  MAJOR(dev), MINOR(dev)
 #define show_dev_ino(entry)show_dev(entry->dev), (unsigned long)entry->ino
 
+#ifndef _TRACE_F2FS_ENUM_H
+#define _TRACE_F2FS_ENUM_H
+enum f2fs_cp_phase {
+   CP_PHASE_START_BLOCK_OPS,
+   CP_PHASE_FINISH_BLOCK_OPS,
+   CP_PHASE_FINISH_CHECKPOINT,
+};
+#endif /* _TRACE_F2FS_ENUM_H */
+
 TRACE_DEFINE_ENUM(NODE);
 TRACE_DEFINE_ENUM(DATA);
 TRACE_DEFINE_ENUM(META);
@@ -50,6 +59,9 @@ 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 +187,12 @@ 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 +1591,26 @@ 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.rc1.455.g30608eb744-goog



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[f2fs-dev] [PATCH v2] f2fs: optimize trace_f2fs_write_checkpoint with enums

2025-11-27 Thread YH Lin via Linux-f2fs-devel
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 
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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