Re: [PATCH v2] erofs: add folio order to trace_erofs_read_folio

[Gao Xiang]

On 2026/6/17 15:43, Zhan Xusheng wrote:

erofs supports large folios for reads, but the actual folio order
instantiated in the page cache may be lower due to allocation
constraints such as memory fragmentation.

trace_erofs_read_folio already receives the folio being read but
currently records only its index. Add folio_order() to the tracepoint
so that users can observe the realized folio order and verify the
effectiveness of large folio reads.

Also drop the uptodate field: read_folio() is only called for a
non-uptodate folio, so it is always 0.

Suggested-by: Gao Xiang <hsiang...@linux.alibaba.com>
Signed-off-by: Zhan Xusheng <zhanxush...@xiaomi.com>

Reviewed-by: Gao Xiang <hsiang...@linux.alibaba.com>

But pls also Cc erofs mailing list <linux-erofs@lists.ozlabs.org>
next time

Thanks,
Gao Xiang

---
  include/trace/events/erofs.h | 9 ++++-----
  1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/include/trace/events/erofs.h b/include/trace/events/erofs.h
index cd0e3fd8c23f..0a178cb10fb1 100644
--- a/include/trace/events/erofs.h
+++ b/include/trace/events/erofs.h
@@ -90,7 +90,7 @@ TRACE_EVENT(erofs_read_folio,
                __field(erofs_nid_t,    nid     )
                __field(int,            dir     )
                __field(pgoff_t,        index   )
-               __field(int,            uptodate)
+               __field(unsigned int,   order   )
                __field(bool,           raw     )
        ),

@@ -99,16 +99,15 @@ TRACE_EVENT(erofs_read_folio,

                __entry->nid = EROFS_I(inode)->nid;
                __entry->dir = S_ISDIR(inode->i_mode);
                __entry->index       = folio->index;
-               __entry->uptodate = folio_test_uptodate(folio);
+               __entry->order       = folio_order(folio);
                __entry->raw = raw;
        ),

- TP_printk("dev = (%d,%d), nid = %llu, %s, index = %lu, uptodate = %d "

-               "raw = %d",
+       TP_printk("dev = (%d,%d), nid = %llu, %s, index = %lu, order = %u, raw = 
%d",
                show_dev_nid(__entry),
                show_file_type(__entry->dir),
                (unsigned long)__entry->index,
-               __entry->uptodate,
+               __entry->order,
                __entry->raw)
  );