[Devel] [PATCH RHEL9 COMMIT] mm: Drop swap_cache_info reporting in vzstat

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-362.8.1.vz9.35.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-362.8.1.vz9.35.4
------>
commit 544856295cf64cdeae52fda5eac77df49061f9f8
Author: Konstantin Khorenko <khorenko at virtuozzo.com>
Date:   Thu Dec 28 19:50:51 2023 +0300

    mm: Drop swap_cache_info reporting in vzstat
    
    Mainstream has dropped swap_cache_info statistics:
     442701e7058b ("mm/swap: remove swap_cache_info statistics")
    
    So we are dropping reporting it via /proc/vz/stats interface.
    
    We could leave the format of /proc/vz/stats file the same (it is an
    interface after all, should be stable), but as in vz9 we'll have so many
    changes, vzstat utility is also should be rewritten, so it's a good time
    to drop the junk code rathen than preserve the interface file format.
    
    Of course we inc the format version to 2.7.
    
    This patch:
     * fully reverts 44a915de19aa ("mm: Export swap_cache_info struct and
       variable")
     * removes couple of hunks in 5952b9c2f339 ("vzstat: Add vzstat module and
       kstat interfaces") - related to swap_cache_info
    
    https://virtuozzo.atlassian.net/browse/PSBM-152466
    
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
    
    Feature: ve: extra statistics (mm, latency)
---
 include/linux/swap.h   |  9 ---------
 include/linux/vzstat.h |  7 -------
 kernel/ve/vzstat.c     | 16 +---------------
 mm/swap_state.c        |  3 ---
 4 files changed, 1 insertion(+), 34 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 9348574b5bb7..1af5b711bc00 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -715,14 +715,5 @@ static inline bool mem_cgroup_swap_full(struct page *page)
 }
 #endif
 
-struct swap_cache_info {
-	unsigned long add_total;
-	unsigned long del_total;
-	unsigned long find_success;
-	unsigned long find_total;
-};
-
-extern struct swap_cache_info swap_cache_info;
-
 #endif /* __KERNEL__*/
 #endif /* _LINUX_SWAP_H */
diff --git a/include/linux/vzstat.h b/include/linux/vzstat.h
index 505487117ca4..4a5738bd036f 100644
--- a/include/linux/vzstat.h
+++ b/include/linux/vzstat.h
@@ -14,13 +14,6 @@
 #include <linux/mmzone.h>
 #include <linux/kstat.h>
 
-struct swap_cache_info_struct {
-	unsigned long add_total;
-	unsigned long del_total;
-	unsigned long find_success;
-	unsigned long find_total;
-};
-
 struct kstat_zone_avg {
 	unsigned long		free_pages_avg[3],
 				nr_active_avg[3],
diff --git a/kernel/ve/vzstat.c b/kernel/ve/vzstat.c
index 7ffd5ec7f2a3..73063a4189d7 100644
--- a/kernel/ve/vzstat.c
+++ b/kernel/ve/vzstat.c
@@ -27,7 +27,6 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 #include <linux/veowner.h>
-#include <linux/swap.h>
 
 #include <linux/vzstat.h>
 
@@ -385,18 +384,6 @@ static void kernel_text_csum_seq_show(struct seq_file *m, void *v)
 	seq_printf(m, "kernel_text_csum_broken: %d\n", 0);
 }
 
-static void swap_cache_seq_show(struct seq_file *m, void *v)
-{
-	struct swap_cache_info *swpcache;
-
-	swpcache = &swap_cache_info;
-	seq_printf(m, "Swap cache: add %lu, del %lu, find %lu/%lu\n",
-			swpcache->add_total,
-			swpcache->del_total,
-			swpcache->find_success,
-			swpcache->find_total);
-}
-
 /*
  * Declare special structure to store summarized statistics. The 'struct zone'
  * is not used because of it's tremendous size.
@@ -668,14 +655,13 @@ static int stats_seq_show(struct seq_file *m, void *v)
 {
 	if (!v)
 		return 0;
-	seq_puts(m, "Version: 2.6\n");
+	seq_puts(m, "Version: 2.7\n");
 	cycles_per_jiffy_show(m, v);
 	jiffies_per_second_show(m, v);
 	seq_puts(m, "\nLoad info:\n");
 	task_counts_seq_show(m, v);
 	seq_puts(m, "\nMemory info:\n");
 	kernel_text_csum_seq_show(m, v);
-	swap_cache_seq_show(m, v);
 	mem_free_areas_show(m, v);
 	mem_avg_show(m, v);
 	mem_fails_show(m, v);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 034dd5d0c6d9..b16dc348bbd2 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -59,9 +59,6 @@ static bool enable_vma_readahead __read_mostly = true;
 #define GET_SWAP_RA_VAL(vma)					\
 	(atomic_long_read(&(vma)->swap_readahead_info) ? : 4)
 
-struct swap_cache_info swap_cache_info;
-EXPORT_SYMBOL_GPL(swap_cache_info);
-
 static atomic_t swapin_readahead_hits = ATOMIC_INIT(4);
 
 void show_swap_cache_info(void)