dm writecache: add cond_resched to avoid CPU hangs (1edaa447) · Commits · 戴 / test

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>

drivers/md/dm-writecache.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -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);

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