mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG

[linux-2.6-microblaze.git] / mm / page_io.c

diff --git a/mm/page_io.c b/mm/page_io.c
index 60a66a5..3a198de 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -22,6 +22,7 @@
 #include <linux/writeback.h>
 #include <linux/frontswap.h>
 #include <linux/blkdev.h>
+#include <linux/psi.h>
 #include <linux/uio.h>
 #include <linux/sched/task.h>
 #include <asm/pgtable.h>
@@ -354,10 +355,19 @@ int swap_readpage(struct page *page, bool synchronous)
        struct swap_info_struct *sis = page_swap_info(page);
        blk_qc_t qc;
        struct gendisk *disk;
+       unsigned long pflags;
 
        VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);
        VM_BUG_ON_PAGE(!PageLocked(page), page);
        VM_BUG_ON_PAGE(PageUptodate(page), page);
+
+       /*
+        * Count submission time as memory stall. When the device is congested,
+        * or the submitting cgroup IO-throttled, submission can be a
+        * significant part of overall IO time.
+        */
+       psi_memstall_enter(&pflags);
+
        if (frontswap_load(page) == 0) {
                SetPageUptodate(page);
                unlock_page(page);
@@ -371,7 +381,7 @@ int swap_readpage(struct page *page, bool synchronous)
                ret = mapping->a_ops->readpage(swap_file, page);
                if (!ret)
                        count_vm_event(PSWPIN);
-               return ret;
+               goto out;
        }
 
        ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
@@ -382,7 +392,7 @@ int swap_readpage(struct page *page, bool synchronous)
                }
 
                count_vm_event(PSWPIN);
-               return 0;
+               goto out;
        }
 
        ret = 0;
@@ -418,6 +428,7 @@ int swap_readpage(struct page *page, bool synchronous)
        bio_put(bio);
 
 out:
+       psi_memstall_leave(&pflags);
        return ret;
 }