mm/swapfile.c: delete the "last_in_cluster < scan_base" loop in the body of scan_swap_map() (50088c44) · Commits · 戴 / test

mm/swapfile.c

+3 −26

Original line number	Diff line number	Diff line
		@@ -523,12 +523,9 @@ static unsigned long scan_swap_map(struct swap_info_struct *si,
		/*
		* If seek is expensive, start searching for new cluster from
		* start of partition, to minimize the span of allocated swap.
		* But if seek is cheap, search from our current position, so
		* that swap is allocated from all over the partition: if the
		* Flash Translation Layer only remaps within limited zones,
		* we don't want to wear out the first zone too quickly.
		* If seek is cheap, that is the SWP_SOLIDSTATE si->cluster_info
		* case, just handled by scan_swap_map_try_ssd_cluster() above.
		*/
		if (!(si->flags & SWP_SOLIDSTATE))
		scan_base = offset = si->lowest_bit;
		last_in_cluster = offset + SWAPFILE_CLUSTER - 1;

		@@ -549,26 +546,6 @@ static unsigned long scan_swap_map(struct swap_info_struct *si,
		}
		}

		offset = si->lowest_bit;
		last_in_cluster = offset + SWAPFILE_CLUSTER - 1;

		/* Locate the first empty (unaligned) cluster */
		for (; last_in_cluster < scan_base; offset++) {
		if (si->swap_map[offset])
		last_in_cluster = offset + SWAPFILE_CLUSTER;
		else if (offset == last_in_cluster) {
		spin_lock(&si->lock);
		offset -= SWAPFILE_CLUSTER - 1;
		si->cluster_next = offset;
		si->cluster_nr = SWAPFILE_CLUSTER - 1;
		goto checks;
		}
		if (unlikely(--latency_ration < 0)) {
		cond_resched();
		latency_ration = LATENCY_LIMIT;
		}
		}

		offset = scan_base;
		spin_lock(&si->lock);
		si->cluster_nr = SWAPFILE_CLUSTER - 1;