On Sun, Oct 11, 2020 at 9:53 PM Mike Rapoport <rppt@xxxxxxxxxx> wrote: > > On Sat, Oct 10, 2020 at 06:38:54PM +0800, Muchun Song wrote: > > The amount of memory allocated to sockets buffer can become significant. > > However, we do not display the amount of memory consumed by sockets > > buffer. In this case, knowing where the memory is consumed by the kernel > > is very difficult. On our server with 500GB RAM, sometimes we can see > > 25GB disappear through /proc/meminfo. After our analysis, we found the > > following memory allocation path which consumes the memory with page_owner > > enabled. > > I have a high lelel question. > There is accounting of the socket memory for memcg that gets called from > the networking layer. Did you check if the same call sites can be used > for the system-wide accounting as well? I also think about this. But we did not pass the `struct page` parameter to the sock accounting memcg API. So we did not know the NUMA node which allocated the socket buffer memory and cannot do node-level statistics. In addition, there is another problem. If the user sends a 4096-byte message, we only charge one page to the memcg but the system allocates 8 pages. So if we reuse the same call sites for the system-wide accounting, the statistical count we get is always smaller than the actual situation. > > > 849698 times: > > Page allocated via order 3, mask 0x4052c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP) > > __alloc_pages_nodemask+0x11d/0x290 > > skb_page_frag_refill+0x68/0xf0 > > sk_page_frag_refill+0x19/0x70 > > tcp_sendmsg_locked+0x2f4/0xd10 > > tcp_sendmsg+0x29/0xa0 > > sock_sendmsg+0x30/0x40 > > sock_write_iter+0x8f/0x100 > > __vfs_write+0x10b/0x190 > > vfs_write+0xb0/0x190 > > ksys_write+0x5a/0xd0 > > do_syscall_64+0x5d/0x110 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > > --- > > drivers/base/node.c | 2 ++ > > drivers/net/virtio_net.c | 3 +-- > > Is virtio-net the only dirver that requred an update? Yeah, only virtio-net needs an update. Because only it uses the skb_page_frag_refill() API. > > > fs/proc/meminfo.c | 1 + > > include/linux/mmzone.h | 1 + > > include/linux/skbuff.h | 43 ++++++++++++++++++++++++++++++++++++++-- > > kernel/exit.c | 3 +-- > > mm/page_alloc.c | 7 +++++-- > > mm/vmstat.c | 1 + > > net/core/sock.c | 8 ++++---- > > net/ipv4/tcp.c | 3 +-- > > net/xfrm/xfrm_state.c | 3 +-- > > 11 files changed, 59 insertions(+), 16 deletions(-) > > -- Yours, Muchun
