[PATCH v2 6/7] mm, proc: add KReclaimable to /proc/meminfo

From: Vlastimil Babka
Date: Mon Jun 18 2018 - 05:20:03 EST


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

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
Documentation/filesystems/proc.txt | 4 ++++
drivers/base/node.c | 19 ++++++++++++-------
fs/proc/meminfo.c | 16 ++++++++--------
3 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 520f6a84cf50..6a255f960ab5 100644
--- a/Documentation/filesystems/proc.txt
+++ b/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
@@ -921,6 +922,9 @@ AnonHugePages: Non-file backed huge pages mapped into userspace page tables
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
diff --git a/drivers/base/node.c b/drivers/base/node.c
index a5e821d09656..81cef8031eae 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -67,8 +67,11 @@ static ssize_t node_read_meminfo(struct device *dev,
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 device *dev,
"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 device *dev,
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;
}
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 2fb04846ed11..61a18477bc07 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -37,6 +37,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
long cached;
long available;
unsigned long pages[NR_LRU_LISTS];
+ unsigned long sreclaimable, sunreclaim;
int lru;

si_meminfo(&i);
@@ -52,6 +53,8 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
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);
@@ -93,14 +96,11 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
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: ",
--
2.17.1