| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 102/146] dm writecache: add cond_resched to avoid CPU hangs | Date | Thu, 16 Apr 2020 15:24:03 +0200 |
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From: Mikulas Patocka <mpatocka@redhat.com>
commit 1edaa447d958bec24c6a79685a5790d98976fd16 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-writecache.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -878,6 +878,7 @@ static int writecache_alloc_entries(stru struct wc_entry *e = &wc->entries[b]; e->index = b; e->write_in_progress = false; + cond_resched(); } return 0; @@ -932,6 +933,7 @@ static void writecache_resume(struct dm_ 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++) { @@ -1764,8 +1766,10 @@ static int init_memory(struct dm_writeca 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);
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