LU-16338 readahead: add stats for read-ahead page count

This patch adds the stats for read-ahead page count:

lctl get_param llite.*.read_ahead_stats
llite.lustre-ffff938b7849d000.read_ahead_stats=
snapshot_time             4011.320890492 secs.nsecs
start_time                0.000000000 secs.nsecs
elapsed_time              4011.320890492 secs.nsecs
hits                      4 samples [pages]
misses                    1 samples [pages]
zero_size_window          4 samples [pages]
failed_to_reach_end       1 samples [pages]
failed_to_fast_read       1 samples [pages]
readahead_pages           1 samples [pages] 255 255 255

Lustre-change: https://review.whamcloud.com/49224
Lustre-commit: cdcf97e17e73dfdd65c4e46bb30c4a07f5e710cf

Signed-off-by: Qian Yingjin <qian@ddn.com>
Change-Id: Iada06eb7d78ab28cfcc7167e49d25da252da4009
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Patrick Farrell <farr0186@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/50070
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>

diff --git a/lustre/llite/llite_internal.h b/lustre/llite/llite_internal.h
index 2873534..74de436 100644 (file)
--- a/lustre/llite/llite_internal.h
+++ b/lustre/llite/llite_internal.h
@@ -641,6 +641,7 @@ enum ra_stat {
        RA_STAT_ASYNC,
        RA_STAT_FAILED_FAST_READ,
        RA_STAT_MMAP_RANGE_READ,
+       RA_STAT_READAHEAD_PAGES,
        _NR_RA_STAT,
 };
 

diff --git a/lustre/llite/lproc_llite.c b/lustre/llite/lproc_llite.c
index bac4c78..5612a41 100644 (file)
--- a/lustre/llite/lproc_llite.c
+++ b/lustre/llite/lproc_llite.c
@@ -2195,6 +2195,7 @@ static const char *ra_stat_string[] = {
        [RA_STAT_ASYNC]                 = "async_readahead",
        [RA_STAT_FAILED_FAST_READ]      = "failed_to_fast_read",
        [RA_STAT_MMAP_RANGE_READ]       = "mmap_range_read",
+       [RA_STAT_READAHEAD_PAGES]       = "readahead_pages"
 };
 
 int ll_debugfs_register_super(struct super_block *sb, const char *name)
@@ -2255,9 +2256,15 @@ int ll_debugfs_register_super(struct super_block *sb, const char *name)
        if (sbi->ll_ra_stats == NULL)
                GOTO(out_stats, err = -ENOMEM);
 
-       for (id = 0; id < ARRAY_SIZE(ra_stat_string); id++)
-               lprocfs_counter_init(sbi->ll_ra_stats, id, 0,
-                                    ra_stat_string[id], "pages");
+       for (id = 0; id < ARRAY_SIZE(ra_stat_string); id++) {
+               if (id == RA_STAT_READAHEAD_PAGES)
+                       lprocfs_counter_init(sbi->ll_ra_stats, id,
+                                            LPROCFS_CNTR_AVGMINMAX,
+                                            ra_stat_string[id], "pages");
+               else
+                       lprocfs_counter_init(sbi->ll_ra_stats, id, 0,
+                                            ra_stat_string[id], "pages");
+       }
 
        debugfs_create_file("read_ahead_stats", 0644, sbi->ll_debugfs_entry,
                            sbi->ll_ra_stats, &ldebugfs_stats_seq_fops);

diff --git a/lustre/llite/rw.c b/lustre/llite/rw.c
index 87e89d0..efa9b1b 100644 (file)
--- a/lustre/llite/rw.c
+++ b/lustre/llite/rw.c
@@ -149,9 +149,18 @@ static inline bool ll_readahead_enabled(struct ll_sb_info *sbi)
 void ll_ra_stats_inc(struct inode *inode, enum ra_stat which)
 {
        struct ll_sb_info *sbi = ll_i2sbi(inode);
+
        ll_ra_stats_inc_sbi(sbi, which);
 }
 
+void ll_ra_stats_add(struct inode *inode, enum ra_stat which, long count)
+{
+       struct ll_sb_info *sbi = ll_i2sbi(inode);
+
+       LASSERTF(which < _NR_RA_STAT, "which: %u\n", which);
+       lprocfs_counter_add(sbi->ll_ra_stats, which, count);
+}
+
 #define RAS_CDEBUG(ras) \
        CDEBUG(D_READA,                                                      \
               "lre %llu cr %lu cb %llu wsi %lu wp %lu nra %lu rpc %lu "     \
@@ -525,6 +534,10 @@ ll_read_ahead_pages(const struct lu_env *env, struct cl_io *io,
 
        cl_read_ahead_release(env, &ra);
 
+       if (count)
+               ll_ra_stats_add(vvp_object_inode(io->ci_obj),
+                               RA_STAT_READAHEAD_PAGES, count);
+
        return count;
 }
 

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index b908453..f17c6cb 100755 (executable)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -10761,6 +10761,20 @@ test_101l() {
 }
 run_test 101l "verify changing mmap ra logic doesn't crash"
 
+test_101m()
+{
+       local file=$DIR/$tfile
+
+       check_set_fallocate_or_skip
+
+       $LCTL set_param -n llite.*.read_ahead_stats=0
+       fallocate -l 16K $file || error "failed to fallocate $file"
+       cancel_lru_locks osc
+       $MULTIOP $file or1048576c
+       $LCTL get_param llite.*.read_ahead_stats
+}
+run_test 101m "read ahead for small file"
+
 setup_test102() {
        test_mkdir $DIR/$tdir
        chown $RUNAS_ID $DIR/$tdir