FROMLIST: mm: fs: Invalidate BH LRU during page migration

Pages containing buffer_heads that are in one of the per-CPU
buffer_head LRU caches will be pinned and thus cannot be migrated.
This can prevent CMA allocations from succeeding, which are often used
on platforms with co-processors (such as a DSP) that can only use
physically contiguous memory. It can also prevent memory
hot-unplugging from succeeding, which involves migrating at least
MIN_MEMORY_BLOCK_SIZE bytes of memory, which ranges from 8 MiB to 1
GiB based on the architecture in use.

Correspondingly, invalidate the BH LRU caches before a migration
starts and stop any buffer_head from being cached in the LRU caches,
until migration has finished.

Bug: 180018981
Link: https://lore.kernel.org/linux-mm/20210310161429.399432-3-minchan@kernel.org/
Signed-off-by: Chris Goldsworthy <cgoldswo@codeaurora.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I7ac085c2ec14a81c3c4d7b65a7eeedb0cfba4ea6
This commit is contained in:
Minchan Kim
2021-03-11 15:28:55 -08:00
parent 3039d8580c
commit 169ddec367
3 changed files with 18 additions and 3 deletions

View File

@@ -36,6 +36,7 @@
#include <linux/hugetlb.h>
#include <linux/page_idle.h>
#include <linux/local_lock.h>
#include <linux/buffer_head.h>
#include "internal.h"
@@ -665,6 +666,7 @@ void lru_add_drain_cpu(int cpu)
pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL);
activate_page_drain(cpu);
invalidate_bh_lru(NULL);
}
/**
@@ -852,7 +854,8 @@ static void __lru_add_drain_all(bool force_all_cpus)
pagevec_count(&per_cpu(lru_pvecs.lru_deactivate_file, cpu)) ||
pagevec_count(&per_cpu(lru_pvecs.lru_deactivate, cpu)) ||
pagevec_count(&per_cpu(lru_pvecs.lru_lazyfree, cpu)) ||
need_activate_page_drain(cpu)) {
need_activate_page_drain(cpu) ||
has_bh_in_lru(cpu, NULL)) {
INIT_WORK(work, lru_add_drain_per_cpu);
queue_work_on(cpu, mm_percpu_wq, work);
__cpumask_set_cpu(cpu, &has_work);