From 1edaa447d958bec24c6a79685a5790d98976fd16 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 27 Mar 2020 07:22:36 -0400 Subject: [PATCH] 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 Signed-off-by: Mike Snitzer --- drivers/md/dm-writecache.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index e274e5a4d425..114927da9cc9 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);