dm writecache: add cond_resched to avoid CPU hangs
Initializing a dm-writecache device can take a long time when the
persistent memory device is large. Add cond_resched() to a few loops
to avoid warnings that the CPU is stuck.
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index e274e5a..114927d 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -925,6 +925,7 @@ static int writecache_alloc_entries(struct dm_writecache *wc)
struct wc_entry *e = &wc->entries[b];
e->index = b;
e->write_in_progress = false;
+ cond_resched();
}
return 0;
@@ -979,6 +980,7 @@ static void writecache_resume(struct dm_target *ti)
e->original_sector = le64_to_cpu(wme.original_sector);
e->seq_count = le64_to_cpu(wme.seq_count);
}
+ cond_resched();
}
#endif
for (b = 0; b < wc->n_blocks; b++) {
@@ -1886,8 +1888,10 @@ static int init_memory(struct dm_writecache *wc)
pmem_assign(sb(wc)->n_blocks, cpu_to_le64(wc->n_blocks));
pmem_assign(sb(wc)->seq_count, cpu_to_le64(0));
- for (b = 0; b < wc->n_blocks; b++)
+ for (b = 0; b < wc->n_blocks; b++) {
write_original_sector_seq_count(wc, &wc->entries[b], -1, -1);
+ cond_resched();
+ }
writecache_flush_all_metadata(wc);
writecache_commit_flushed(wc, false);