From: Vlastimil Babka <vbabka@xxxxxxx> Subject: mm, proc: add KReclaimable to /proc/meminfo The vmstat NR_KERNEL_MISC_RECLAIMABLE counter is for kernel non-slab allocations that can be reclaimed via shrinker. In /proc/meminfo, we can show the sum of all reclaimable kernel allocations (including slab) as "KReclaimable". Add the same counter also to per-node meminfo under /sys With this counter, users will have more complete information about kernel memory usage. Non-slab reclaimable pages (currently just the ION allocator) will not be missing from /proc/meminfo, making users wonder where part of their memory went. More precisely, they already appear in MemAvailable, but without the new counter, it's not obvious why the value in MemAvailable doesn't fully correspond with the sum of other counters participating in it. Link: http://lkml.kernel.org/r/20180731090649.16028-6-vbabka@xxxxxxx Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Laura Abbott <labbott@xxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Cc: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/filesystems/proc.txt | 4 ++++ drivers/base/node.c | 19 ++++++++++++------- fs/proc/meminfo.c | 16 ++++++++-------- 3 files changed, 24 insertions(+), 15 deletions(-) --- a/Documentation/filesystems/proc.txt~mm-proc-add-kreclaimable-to-proc-meminfo +++ a/Documentation/filesystems/proc.txt @@ -858,6 +858,7 @@ Writeback: 0 kB AnonPages: 861800 kB Mapped: 280372 kB Shmem: 644 kB +KReclaimable: 168048 kB Slab: 284364 kB SReclaimable: 159856 kB SUnreclaim: 124508 kB @@ -925,6 +926,9 @@ AnonHugePages: Non-file backed huge page ShmemHugePages: Memory used by shared memory (shmem) and tmpfs allocated with huge pages ShmemPmdMapped: Shared memory mapped into userspace with huge pages +KReclaimable: Kernel allocations that the kernel will attempt to reclaim + under memory pressure. Includes SReclaimable (below), and other + direct allocations with a shrinker. Slab: in-kernel data structures cache SReclaimable: Part of Slab, that might be reclaimed, such as caches SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure --- a/drivers/base/node.c~mm-proc-add-kreclaimable-to-proc-meminfo +++ a/drivers/base/node.c @@ -67,8 +67,11 @@ static ssize_t node_read_meminfo(struct int nid = dev->id; struct pglist_data *pgdat = NODE_DATA(nid); struct sysinfo i; + unsigned long sreclaimable, sunreclaimable; si_meminfo_node(&i, nid); + sreclaimable = node_page_state(pgdat, NR_SLAB_RECLAIMABLE); + sunreclaimable = node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE); n = sprintf(buf, "Node %d MemTotal: %8lu kB\n" "Node %d MemFree: %8lu kB\n" @@ -118,6 +121,7 @@ static ssize_t node_read_meminfo(struct "Node %d NFS_Unstable: %8lu kB\n" "Node %d Bounce: %8lu kB\n" "Node %d WritebackTmp: %8lu kB\n" + "Node %d KReclaimable: %8lu kB\n" "Node %d Slab: %8lu kB\n" "Node %d SReclaimable: %8lu kB\n" "Node %d SUnreclaim: %8lu kB\n" @@ -138,20 +142,21 @@ static ssize_t node_read_meminfo(struct nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)), nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)), nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), - nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE) + - node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)), - nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE)), + nid, K(sreclaimable + + node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)), + nid, K(sreclaimable + sunreclaimable), + nid, K(sreclaimable), + nid, K(sunreclaimable) #ifdef CONFIG_TRANSPARENT_HUGEPAGE - nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)), + , nid, K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR), nid, K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR), nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) * - HPAGE_PMD_NR)); -#else - nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE))); + HPAGE_PMD_NR) #endif + ); n += hugetlb_report_node_meminfo(nid, buf + n); return n; } --- a/fs/proc/meminfo.c~mm-proc-add-kreclaimable-to-proc-meminfo +++ a/fs/proc/meminfo.c @@ -38,6 +38,7 @@ static int meminfo_proc_show(struct seq_ long cached; long available; unsigned long pages[NR_LRU_LISTS]; + unsigned long sreclaimable, sunreclaim; int lru; si_meminfo(&i); @@ -53,6 +54,8 @@ static int meminfo_proc_show(struct seq_ pages[lru] = global_node_page_state(NR_LRU_BASE + lru); available = si_mem_available(); + sreclaimable = global_node_page_state(NR_SLAB_RECLAIMABLE); + sunreclaim = global_node_page_state(NR_SLAB_UNRECLAIMABLE); show_val_kb(m, "MemTotal: ", i.totalram); show_val_kb(m, "MemFree: ", i.freeram); @@ -94,14 +97,11 @@ static int meminfo_proc_show(struct seq_ show_val_kb(m, "Mapped: ", global_node_page_state(NR_FILE_MAPPED)); show_val_kb(m, "Shmem: ", i.sharedram); - show_val_kb(m, "Slab: ", - global_node_page_state(NR_SLAB_RECLAIMABLE) + - global_node_page_state(NR_SLAB_UNRECLAIMABLE)); - - show_val_kb(m, "SReclaimable: ", - global_node_page_state(NR_SLAB_RECLAIMABLE)); - show_val_kb(m, "SUnreclaim: ", - global_node_page_state(NR_SLAB_UNRECLAIMABLE)); + show_val_kb(m, "KReclaimable: ", sreclaimable + + global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE)); + show_val_kb(m, "Slab: ", sreclaimable + sunreclaim); + show_val_kb(m, "SReclaimable: ", sreclaimable); + show_val_kb(m, "SUnreclaim: ", sunreclaim); seq_printf(m, "KernelStack: %8lu kB\n", global_zone_page_state(NR_KERNEL_STACK_KB)); show_val_kb(m, "PageTables: ", _
