Whamcloud - gitweb
LU-15069 llite: Add start_idx debug 74/45674/10
authorPatrick Farrell <pfarrell@whamcloud.com>
Wed, 15 Dec 2021 21:27:58 +0000 (16:27 -0500)
committerOleg Drokin <green@whamcloud.com>
Thu, 6 Jan 2022 22:03:32 +0000 (22:03 +0000)
When readahead is triggered, current readahead debug
prints the page the user requested which triggered
readahead and the number of pages read by readahead.

However, readahead does not necessarily start reading from
the user requested page, so it's important to also print
the page where readahead starts.

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: Ie474811f3b0076f4f914fae7f74496e96ddb31da
Reviewed-on: https://review.whamcloud.com/45674
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
lustre/llite/rw.c

index 86436b7..785809d 100644 (file)
@@ -703,12 +703,13 @@ out_free_work:
 static int ll_readahead(const struct lu_env *env, struct cl_io *io,
                        struct cl_page_list *queue,
                        struct ll_readahead_state *ras, bool hit,
-                       struct file *file, pgoff_t skip_index)
+                       struct file *file, pgoff_t skip_index,
+                       pgoff_t *start_idx)
 {
        struct vvp_io *vio = vvp_env_io(env);
        struct ll_thread_info *lti = ll_env_info(env);
        unsigned long pages, pages_min = 0;
-       pgoff_t ra_end_idx = 0, start_idx = 0, end_idx = 0;
+       pgoff_t ra_end_idx = 0, end_idx = 0;
        struct inode *inode;
        struct ra_io_arg *ria = &lti->lti_ria;
        struct cl_object *clob;
@@ -717,8 +718,6 @@ static int ll_readahead(const struct lu_env *env, struct cl_io *io,
        struct ll_sb_info *sbi;
        struct ll_ra_info *ra;
 
-       ENTRY;
-
         ENTRY;
 
        clob = io->ci_obj;
@@ -755,16 +754,16 @@ static int ll_readahead(const struct lu_env *env, struct cl_io *io,
         * so that stride read ahead can work correctly.
         */
        if (stride_io_mode(ras))
-               start_idx = max_t(pgoff_t, ras->ras_next_readahead_idx,
+               *start_idx = max_t(pgoff_t, ras->ras_next_readahead_idx,
                                  ras->ras_stride_offset >> PAGE_SHIFT);
        else
-               start_idx = ras->ras_next_readahead_idx;
+               *start_idx = ras->ras_next_readahead_idx;
 
        if (ras->ras_window_pages > 0)
                end_idx = ras->ras_window_start_idx + ras->ras_window_pages - 1;
 
        if (skip_index)
-               end_idx = start_idx + ras->ras_window_pages - 1;
+               end_idx = *start_idx + ras->ras_window_pages - 1;
 
        /* Enlarge the RA window to encompass the full read */
        if (vio->vui_ra_valid &&
@@ -781,7 +780,7 @@ static int ll_readahead(const struct lu_env *env, struct cl_io *io,
                        ria->ria_eof = true;
                }
        }
-       ria->ria_start_idx = start_idx;
+       ria->ria_start_idx = *start_idx;
        ria->ria_end_idx = end_idx;
        /* If stride I/O mode is detected, get stride window*/
        if (stride_io_mode(ras)) {
@@ -1629,6 +1628,7 @@ int ll_io_read_page(const struct lu_env *env, struct cl_io *io,
        struct vvp_page           *vpg;
        int                        rc = 0, rc2 = 0;
        bool                       uptodate;
+       pgoff_t ra_start_index = 0;
        pgoff_t io_start_index;
        pgoff_t io_end_index;
        ENTRY;
@@ -1674,9 +1674,12 @@ int ll_io_read_page(const struct lu_env *env, struct cl_io *io,
                if (ras->ras_next_readahead_idx < vvp_index(vpg))
                        skip_index = vvp_index(vpg);
                rc2 = ll_readahead(env, io, &queue->c2_qin, ras,
-                                  uptodate, file, skip_index);
-               CDEBUG(D_READA|D_IOTRACE, DFID " %d pages read ahead at %lu\n",
-                      PFID(ll_inode2fid(inode)), rc2, vvp_index(vpg));
+                                  uptodate, file, skip_index,
+                                  &ra_start_index);
+               CDEBUG(D_READA|D_IOTRACE,
+                      DFID " %d pages read ahead at %lu, triggered by user read at %lu\n",
+                      PFID(ll_inode2fid(inode)), rc2, ra_start_index,
+                      vvp_index(vpg));
        } else if (vvp_index(vpg) == io_start_index &&
                   io_end_index - io_start_index > 0) {
                rc2 = ll_readpages(env, io, &queue->c2_qin, io_start_index + 1,