[no subject]

<stats log>
============
[Thread 0] Scanned group range [0, 1599), inodes 169076
e2fsck_pass1_merge_context [0]: bg range [0, 1599] elapsed time: 18.580 count=25573571
elapsed time: 32.863

"count" in above stat measures total no. of extent entries found in thread_ctx->block_found_map
(by adding rb_count_bmap() function). Since there is only one thread here, that also means it is the total no.
of extent entries. Above data is shown with "-m 1", to just show the exact count entries.
Otherwise too with "-m 4", the performance is degraded.

I have also tested this on raid0 using 2 HDDs, and on that too perf degradation was observed.
(Although I don't have the exact data handy for this, but I can get those again, if needed).
But AFAIK, it was definitely a significant reduction in perf numbers.

So I was wondering if this is a known limitation around pfsck and if it has popped up in any of your tests too.
Also please do let me know if I have missed anything obvious here?

In some of my earlier testing, I had tested with lusture e2fsprogs (master-pfsck branch) and had similar observations
as mentioned above. But recently all my tests were based out of the following tree[2] (with patch[3] included).
I have these setups available with me, so if anything is needed to be tested from my end, I can do that.

References
============
[1]: https://lore.kernel.org/all/YMN10sXgoTR%2FIPxr@xxxxxxx/
[2]: https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/log/?h=pfsck
[3] https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/commit/?id=699di448eee4b991acafaae4e4f8222be332d6837


Thanks for your help!!
-ritesh

--

<script1.sh>
============
fragmented_filesize=$((10 * 1024 * 1024 * 1024))
dir_cnt=0
while [ $dir_cnt -lt 8192 ]; do
   mkdir $MNT/n$dir_cnt || break
   inode_cnt=0
   while [ $inode_cnt -lt 8192 ]; do
       if [ $inode_cnt -eq 0 ]; then
           xfs_io -fc "falloc 0 $fragmented_filesize" $MNT/n$dir_cnt/n$inode_cnt
       else
           touch $MNT/n$dir_cnt/n$inode_cnt || break
       fi
       inode_cnt=$((inode_cnt+1))
   done
   dir_cnt=$((dir_cnt+1))
done
exit

<script2.sh>
==============
dir_cnt=0
while [ $dir_cnt -lt 8192 ]; do
    inode_cnt=0
    $XFSTESTS_PATH/src/punch-alternating $MNT/n$dir_cnt/n$inode_cnt
    dir_cnt=$((dir_cnt+1))
done