--- zzzz-none-000/linux-3.10.107/fs/proc/meminfo.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/proc/meminfo.c	2021-02-04 17:41:59.000000000 +0000
@@ -1,8 +1,8 @@
 #include <linux/fs.h>
-#include <linux/hugetlb.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/hugetlb.h>
 #include <linux/mman.h>
 #include <linux/mmzone.h>
 #include <linux/proc_fs.h>
@@ -12,6 +12,9 @@
 #include <linux/vmstat.h>
 #include <linux/atomic.h>
 #include <linux/vmalloc.h>
+#ifdef CONFIG_CMA
+#include <linux/cma.h>
+#endif
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include "internal.h"
@@ -24,10 +27,12 @@
 {
 	struct sysinfo i;
 	unsigned long committed;
-	unsigned long allowed;
-	struct vmalloc_info vmi;
 	long cached;
+	long available;
+	unsigned long pagecache;
+	unsigned long wmark_low = 0;
 	unsigned long pages[NR_LRU_LISTS];
+	struct zone *zone;
 	int lru;
 
 /*
@@ -37,25 +42,60 @@
 	si_meminfo(&i);
 	si_swapinfo(&i);
 	committed = percpu_counter_read_positive(&vm_committed_as);
-	allowed = ((totalram_pages - hugetlb_total_pages())
-		* sysctl_overcommit_ratio / 100) + total_swap_pages;
 
 	cached = global_page_state(NR_FILE_PAGES) -
 			total_swapcache_pages() - i.bufferram;
 	if (cached < 0)
 		cached = 0;
 
-	get_vmalloc_info(&vmi);
-
 	for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
 		pages[lru] = global_page_state(NR_LRU_BASE + lru);
 
+	for_each_zone(zone)
+		wmark_low += zone->watermark[WMARK_LOW];
+
+	/*
+	 * Estimate the amount of memory available for userspace allocations,
+	 * without causing swapping.
+	 *
+	 * Free memory cannot be taken below the low watermark, before the
+	 * system starts swapping.
+	 */
+	available = i.freeram - wmark_low;
+
+	/*
+	 * Not all the page cache can be freed, otherwise the system will
+	 * start swapping. Assume at least half of the page cache, or the
+	 * low watermark worth of cache, needs to stay.
+	 */
+	pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
+	pagecache -= min(pagecache / 2, wmark_low);
+	available += pagecache;
+
+	/*
+	 * Part of the reclaimable slab consists of items that are in use,
+	 * and cannot be freed. Cap this estimate at the low watermark.
+	 */
+	available += global_page_state(NR_SLAB_RECLAIMABLE) -
+		     min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
+
+	/*
+	 * Part of the kernel memory, which can be released under memory
+	 * pressure.
+	 */
+	available += global_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES) >>
+		PAGE_SHIFT;
+
+	if (available < 0)
+		available = 0;
+
 	/*
 	 * Tagged format, for easy grepping and expansion.
 	 */
 	seq_printf(m,
 		"MemTotal:       %8lu kB\n"
 		"MemFree:        %8lu kB\n"
+		"MemAvailable:   %8lu kB\n"
 		"Buffers:        %8lu kB\n"
 		"Cached:         %8lu kB\n"
 		"SwapCached:     %8lu kB\n"
@@ -105,9 +145,14 @@
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 		"AnonHugePages:  %8lu kB\n"
 #endif
+#ifdef CONFIG_CMA
+		"CmaTotal:       %8lu kB\n"
+		"CmaFree:        %8lu kB\n"
+#endif
 		,
 		K(i.totalram),
 		K(i.freeram),
+		K(available),
 		K(i.bufferram),
 		K(cached),
 		K(total_swapcache_pages()),
@@ -132,15 +177,9 @@
 		K(i.freeswap),
 		K(global_page_state(NR_FILE_DIRTY)),
 		K(global_page_state(NR_WRITEBACK)),
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-		K(global_page_state(NR_ANON_PAGES)
-		  + global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
-		  HPAGE_PMD_NR),
-#else
 		K(global_page_state(NR_ANON_PAGES)),
-#endif
 		K(global_page_state(NR_FILE_MAPPED)),
-		K(global_page_state(NR_SHMEM)),
+		K(i.sharedram),
 		K(global_page_state(NR_SLAB_RECLAIMABLE) +
 				global_page_state(NR_SLAB_UNRECLAIMABLE)),
 		K(global_page_state(NR_SLAB_RECLAIMABLE)),
@@ -153,18 +192,22 @@
 		K(global_page_state(NR_UNSTABLE_NFS)),
 		K(global_page_state(NR_BOUNCE)),
 		K(global_page_state(NR_WRITEBACK_TEMP)),
-		K(allowed),
+		K(vm_commit_limit()),
 		K(committed),
 		(unsigned long)VMALLOC_TOTAL >> 10,
-		vmi.used >> 10,
-		vmi.largest_chunk >> 10
+		0ul, // used to be vmalloc 'used'
+		0ul  // used to be vmalloc 'largest_chunk'
 #ifdef CONFIG_MEMORY_FAILURE
-		,atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10)
+		, atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10)
 #endif
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-		,K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
+		, K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
 		   HPAGE_PMD_NR)
 #endif
+#ifdef CONFIG_CMA
+		, K(totalcma_pages)
+		, K(global_page_state(NR_FREE_CMA_PAGES))
+#endif
 		);
 
 	hugetlb_report_meminfo(m);
@@ -192,4 +235,4 @@
 	proc_create("meminfo", 0, NULL, &meminfo_proc_fops);
 	return 0;
 }
-module_init(proc_meminfo_init);
+fs_initcall(proc_meminfo_init);