kernel/linux.git/fs/proc/meminfo.c, branch linux-6.0.y

mm: zswap: add basic meminfo and vmstat coverage

2022-05-19T21:08:53+00:00

Currently it requires poking at debugfs to figure out the size and population of the zswap cache on a host. There are no counters for reads and writes against the cache. As a result, it's difficult to understand zswap behavior on production systems. Print zswap memory consumption and how many pages are zswapped out in /proc/meminfo. Count zswapouts and zswapins in /proc/vmstat. Link: https://lkml.kernel.org/r/20220510152847.230957-6-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: David Hildenbrand Cc: Dan Streetman Cc: Michal Hocko Cc: Minchan Kim Cc: Roman Gushchin Cc: Seth Jennings Cc: Shakeel Butt Signed-off-by: Andrew Morton

mm: memcontrol: convert NR_FILE_PMDMAPPED account to pages

2021-02-24T21:38:29+00:00

Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_FILE_PMDMAPPED account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-7-songmuchun@bytedance.com Signed-off-by: Muchun Song Cc: Alexey Dobriyan Cc: Feng Tang Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Michal Hocko Cc: NeilBrown Cc: Pankaj Gupta Cc: Rafael. J. Wysocki Cc: Randy Dunlap Cc: Roman Gushchin Cc: Sami Tolvanen Cc: Shakeel Butt Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: convert NR_SHMEM_PMDMAPPED account to pages

2021-02-24T21:38:29+00:00

Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_SHMEM_PMDMAPPED account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-6-songmuchun@bytedance.com Signed-off-by: Muchun Song Cc: Alexey Dobriyan Cc: Feng Tang Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Michal Hocko Cc: NeilBrown Cc: Pankaj Gupta Cc: Rafael. J. Wysocki Cc: Randy Dunlap Cc: Roman Gushchin Cc: Sami Tolvanen Cc: Shakeel Butt Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: convert NR_SHMEM_THPS account to pages

2021-02-24T21:38:29+00:00

Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_SHMEM_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-5-songmuchun@bytedance.com Signed-off-by: Muchun Song Cc: Alexey Dobriyan Cc: Feng Tang Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Michal Hocko Cc: NeilBrown Cc: Pankaj Gupta Cc: Rafael. J. Wysocki Cc: Randy Dunlap Cc: Roman Gushchin Cc: Sami Tolvanen Cc: Shakeel Butt Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: convert NR_FILE_THPS account to pages

2021-02-24T21:38:29+00:00

Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with if hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_FILE_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Cc: Alexey Dobriyan Cc: Feng Tang Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Michal Hocko Cc: NeilBrown Cc: Pankaj Gupta Cc: Rafael. J. Wysocki Cc: Randy Dunlap Cc: Roman Gushchin Cc: Sami Tolvanen Cc: Shakeel Butt Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: convert NR_ANON_THPS account to pages

2021-02-24T21:38:29+00:00

Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_ANON_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-3-songmuchun@bytedance.com Signed-off-by: Muchun Song Cc: Greg Kroah-Hartman Cc: Rafael. J. Wysocki Cc: Alexey Dobriyan Cc: Johannes Weiner Cc: Vladimir Davydov Cc: Hugh Dickins Cc: Shakeel Butt Cc: Roman Gushchin Cc: Sami Tolvanen Cc: Feng Tang Cc: NeilBrown Cc: Joonsoo Kim Cc: Randy Dunlap Cc: Michal Hocko Cc: Pankaj Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: account pagetables per node

2020-12-15T20:13:40+00:00

For many workloads, pagetable consumption is significant and it makes sense to expose it in the memory.stat for the memory cgroups. However at the moment, the pagetables are accounted per-zone. Converting them to per-node and using the right interface will correctly account for the memory cgroups as well. [akpm@linux-foundation.org: export __mod_lruvec_page_state to modules for arch/mips/kvm/] Link: https://lkml.kernel.org/r/20201130212541.2781790-3-shakeelb@google.com Signed-off-by: Shakeel Butt Acked-by: Johannes Weiner Acked-by: Roman Gushchin Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc/meminfo: avoid open coded reading of vm_committed_as

2020-08-07T18:33:26+00:00

Patch series "make vm_committed_as_batch aware of vm overcommit policy", v6. When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and enlarge it for not-so-strict OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. And for that case, whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. We tested 10+ platforms in 0day (server, desktop and laptop). If we lift it to 64X, 80%+ platforms show improvements, and for 16X lift, 1/3 of the platforms will show improvements. And generally it should help the mmap/unmap usage,as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit : from a larger batch. E.g. large in memory databases which do large : mmaps during startups from multiple threads. Note: There are some style complain from checkpatch for patch 4, as sysctl handler declaration follows the similar format of sibling functions [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ This patch (of 4): Use the existing vm_memory_committed() instead, which is also convenient for future change. Signed-off-by: Feng Tang Signed-off-by: Andrew Morton Acked-by: Michal Hocko Cc: Matthew Wilcox (Oracle) Cc: Johannes Weiner Cc: Mel Gorman Cc: Qian Cai Cc: Kees Cook Cc: Andi Kleen Cc: Tim Chen Cc: Dave Hansen Cc: Huang Ying Cc: Christoph Lameter Cc: Dennis Zhou Cc: Haiyang Zhang Cc: kernel test robot Cc: "K. Y. Srinivasan" Cc: Tejun Heo Link: http://lkml.kernel.org/r/1594389708-60781-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-2-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds

mm: memcontrol: account kernel stack per node

2020-08-07T18:33:25+00:00

Currently the kernel stack is being accounted per-zone. There is no need to do that. In addition due to being per-zone, memcg has to keep a separate MEMCG_KERNEL_STACK_KB. Make the stat per-node and deprecate MEMCG_KERNEL_STACK_KB as memcg_stat_item is an extension of node_stat_item. In addition localize the kernel stack stats updates to account_kernel_stack(). Signed-off-by: Shakeel Butt Signed-off-by: Andrew Morton Reviewed-by: Roman Gushchin Cc: Johannes Weiner Cc: Michal Hocko Link: http://lkml.kernel.org/r/20200630161539.1759185-1-shakeelb@google.com Signed-off-by: Linus Torvalds

mm: memcg: convert vmstat slab counters to bytes

2020-08-07T18:33:24+00:00

In order to prepare for per-object slab memory accounting, convert NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE vmstat items to bytes. To make it obvious, rename them to NR_SLAB_RECLAIMABLE_B and NR_SLAB_UNRECLAIMABLE_B (similar to NR_KERNEL_STACK_KB). Internally global and per-node counters are stored in pages, however memcg and lruvec counters are stored in bytes. This scheme may look weird, but only for now. As soon as slab pages will be shared between multiple cgroups, global and node counters will reflect the total number of slab pages. However memcg and lruvec counters will be used for per-memcg slab memory tracking, which will take separate kernel objects in the account. Keeping global and node counters in pages helps to avoid additional overhead. The size of slab memory shouldn't exceed 4Gb on 32-bit machines, so it will fit into atomic_long_t we use for vmstats. Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Reviewed-by: Shakeel Butt Acked-by: Johannes Weiner Acked-by: Vlastimil Babka Cc: Christoph Lameter Cc: Michal Hocko Cc: Tejun Heo Link: http://lkml.kernel.org/r/20200623174037.3951353-4-guro@fb.com Signed-off-by: Linus Torvalds