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84ad5802a3
The MemAvailable item in /proc/meminfo is to give users a hint of how much memory is allocatable without causing swapping, so it excludes the zones' low watermarks as unavailable to userspace. However, for a userspace allocation, kswapd will actually reclaim until the free pages hit a combination of the high watermark and the page allocator's lowmem protection that keeps a certain amount of DMA and DMA32 memory from userspace as well. Subtract the full amount we know to be unavailable to userspace from the number of free pages when calculating MemAvailable. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
228 lines
5.8 KiB
C
228 lines
5.8 KiB
C
#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/mman.h>
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#include <linux/mmzone.h>
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#include <linux/proc_fs.h>
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#include <linux/quicklist.h>
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#include <linux/seq_file.h>
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#include <linux/swap.h>
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#include <linux/vmstat.h>
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#include <linux/atomic.h>
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#include <linux/vmalloc.h>
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#ifdef CONFIG_CMA
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#include <linux/cma.h>
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#endif
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include "internal.h"
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void __attribute__((weak)) arch_report_meminfo(struct seq_file *m)
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{
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}
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static int meminfo_proc_show(struct seq_file *m, void *v)
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{
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struct sysinfo i;
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unsigned long committed;
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long cached;
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long available;
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unsigned long pagecache;
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unsigned long wmark_low = 0;
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unsigned long pages[NR_LRU_LISTS];
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struct zone *zone;
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int lru;
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/*
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* display in kilobytes.
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*/
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#define K(x) ((x) << (PAGE_SHIFT - 10))
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si_meminfo(&i);
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si_swapinfo(&i);
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committed = percpu_counter_read_positive(&vm_committed_as);
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cached = global_page_state(NR_FILE_PAGES) -
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total_swapcache_pages() - i.bufferram;
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if (cached < 0)
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cached = 0;
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for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
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pages[lru] = global_page_state(NR_LRU_BASE + lru);
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for_each_zone(zone)
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wmark_low += zone->watermark[WMARK_LOW];
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/*
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* Estimate the amount of memory available for userspace allocations,
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* without causing swapping.
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*/
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available = i.freeram - totalreserve_pages;
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/*
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* Not all the page cache can be freed, otherwise the system will
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* start swapping. Assume at least half of the page cache, or the
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* low watermark worth of cache, needs to stay.
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*/
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pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
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pagecache -= min(pagecache / 2, wmark_low);
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available += pagecache;
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/*
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* Part of the reclaimable slab consists of items that are in use,
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* and cannot be freed. Cap this estimate at the low watermark.
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*/
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available += global_page_state(NR_SLAB_RECLAIMABLE) -
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min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
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if (available < 0)
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available = 0;
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/*
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* Tagged format, for easy grepping and expansion.
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*/
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seq_printf(m,
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"MemTotal: %8lu kB\n"
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"MemFree: %8lu kB\n"
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"MemAvailable: %8lu kB\n"
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"Buffers: %8lu kB\n"
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"Cached: %8lu kB\n"
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"SwapCached: %8lu kB\n"
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"Active: %8lu kB\n"
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"Inactive: %8lu kB\n"
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"Active(anon): %8lu kB\n"
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"Inactive(anon): %8lu kB\n"
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"Active(file): %8lu kB\n"
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"Inactive(file): %8lu kB\n"
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"Unevictable: %8lu kB\n"
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"Mlocked: %8lu kB\n"
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#ifdef CONFIG_HIGHMEM
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"HighTotal: %8lu kB\n"
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"HighFree: %8lu kB\n"
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"LowTotal: %8lu kB\n"
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"LowFree: %8lu kB\n"
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#endif
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#ifndef CONFIG_MMU
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"MmapCopy: %8lu kB\n"
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#endif
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"SwapTotal: %8lu kB\n"
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"SwapFree: %8lu kB\n"
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"Dirty: %8lu kB\n"
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"Writeback: %8lu kB\n"
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"AnonPages: %8lu kB\n"
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"Mapped: %8lu kB\n"
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"Shmem: %8lu kB\n"
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"Slab: %8lu kB\n"
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"SReclaimable: %8lu kB\n"
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"SUnreclaim: %8lu kB\n"
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"KernelStack: %8lu kB\n"
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"PageTables: %8lu kB\n"
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#ifdef CONFIG_QUICKLIST
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"Quicklists: %8lu kB\n"
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#endif
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"NFS_Unstable: %8lu kB\n"
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"Bounce: %8lu kB\n"
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"WritebackTmp: %8lu kB\n"
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"CommitLimit: %8lu kB\n"
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"Committed_AS: %8lu kB\n"
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"VmallocTotal: %8lu kB\n"
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"VmallocUsed: %8lu kB\n"
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"VmallocChunk: %8lu kB\n"
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#ifdef CONFIG_MEMORY_FAILURE
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"HardwareCorrupted: %5lu kB\n"
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#endif
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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"AnonHugePages: %8lu kB\n"
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#endif
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#ifdef CONFIG_CMA
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"CmaTotal: %8lu kB\n"
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"CmaFree: %8lu kB\n"
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#endif
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,
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K(i.totalram),
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K(i.freeram),
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K(available),
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K(i.bufferram),
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K(cached),
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K(total_swapcache_pages()),
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K(pages[LRU_ACTIVE_ANON] + pages[LRU_ACTIVE_FILE]),
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K(pages[LRU_INACTIVE_ANON] + pages[LRU_INACTIVE_FILE]),
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K(pages[LRU_ACTIVE_ANON]),
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K(pages[LRU_INACTIVE_ANON]),
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K(pages[LRU_ACTIVE_FILE]),
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K(pages[LRU_INACTIVE_FILE]),
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K(pages[LRU_UNEVICTABLE]),
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K(global_page_state(NR_MLOCK)),
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#ifdef CONFIG_HIGHMEM
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K(i.totalhigh),
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K(i.freehigh),
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K(i.totalram-i.totalhigh),
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K(i.freeram-i.freehigh),
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#endif
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#ifndef CONFIG_MMU
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K((unsigned long) atomic_long_read(&mmap_pages_allocated)),
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#endif
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K(i.totalswap),
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K(i.freeswap),
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K(global_page_state(NR_FILE_DIRTY)),
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K(global_page_state(NR_WRITEBACK)),
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K(global_page_state(NR_ANON_PAGES)),
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K(global_page_state(NR_FILE_MAPPED)),
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K(i.sharedram),
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K(global_page_state(NR_SLAB_RECLAIMABLE) +
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global_page_state(NR_SLAB_UNRECLAIMABLE)),
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K(global_page_state(NR_SLAB_RECLAIMABLE)),
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K(global_page_state(NR_SLAB_UNRECLAIMABLE)),
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global_page_state(NR_KERNEL_STACK) * THREAD_SIZE / 1024,
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K(global_page_state(NR_PAGETABLE)),
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#ifdef CONFIG_QUICKLIST
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K(quicklist_total_size()),
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#endif
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K(global_page_state(NR_UNSTABLE_NFS)),
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K(global_page_state(NR_BOUNCE)),
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K(global_page_state(NR_WRITEBACK_TEMP)),
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K(vm_commit_limit()),
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K(committed),
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(unsigned long)VMALLOC_TOTAL >> 10,
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0ul, // used to be vmalloc 'used'
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0ul // used to be vmalloc 'largest_chunk'
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#ifdef CONFIG_MEMORY_FAILURE
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, atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10)
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#endif
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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, K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
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HPAGE_PMD_NR)
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#endif
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#ifdef CONFIG_CMA
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, K(totalcma_pages)
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, K(global_page_state(NR_FREE_CMA_PAGES))
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#endif
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);
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hugetlb_report_meminfo(m);
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arch_report_meminfo(m);
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return 0;
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#undef K
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}
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static int meminfo_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, meminfo_proc_show, NULL);
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}
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static const struct file_operations meminfo_proc_fops = {
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.open = meminfo_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int __init proc_meminfo_init(void)
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{
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proc_create("meminfo", 0, NULL, &meminfo_proc_fops);
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return 0;
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}
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fs_initcall(proc_meminfo_init);
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