________________________________________ From: owner-freebsd-net@freebsd.orgOn Behalf OfBen RUBSON Sent: Monday, January 2, 2017 11:09:15 AM (UTC+00:00) Monrovia, Reykjavik To: freebsd-net@freebsd.org Cc: Meny Yossefi; Yuval Bason; Hans Petter Selasky Subject: Re: iSCSI failing, MLX rx_ring errors ?
Hi Meny, Thank you very much for your feedback. I think you are right, this could be a mbufs issue. Here are some more numbers : # vmstat -z | grep -v "0, 0$" ITEM SIZE LIMIT USED FREE REQ FAIL SLEEP 4 Bucket: 32, 0, 2673, 28327, 88449799, 17317, 0 8 Bucket: 64, 0, 449, 15609, 13926386, 4871, 0 12 Bucket: 96, 0, 335, 5323, 10293892, 142872, 0 16 Bucket: 128, 0, 533, 6070, 7618615, 472647, 0 32 Bucket: 256, 0, 8317, 22133, 36020376, 563479, 0 64 Bucket: 512, 0, 1238, 3298, 20138111, 11430742, 0 128 Bucket: 1024, 0, 1865, 2963, 21162182, 158752, 0 256 Bucket: 2048, 0, 1626, 450, 80253784, 4890164, 0 mbuf_jumbo_9k: 9216, 603712, 16400, 8744, 4128521064, 2661, 0 # netstat -m 32801/18814/51615 mbufs in use (current/cache/total) 16400/9810/26210/4075058 mbuf clusters in use (current/cache/total/max) 16400/9659 mbuf+clusters out of packet secondary zone in use (current/cache) 0/8647/8647/2037529 4k (page size) jumbo clusters in use (current/cache/total/max) 16400/8744/25144/603712 9k jumbo clusters in use (current/cache/total/max) 0/0/0/339588 16k jumbo clusters in use (current/cache/total/max) 188600K/137607K/326207K bytes allocated to network (current/cache/total) 0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters) 0/0/0 requests for mbufs delayed (mbufs/clusters/mbuf+clusters) 0/0/0 requests for jumbo clusters delayed (4k/9k/16k) 0/2661/0 requests for jumbo clusters denied (4k/9k/16k) 0 sendfile syscalls 0 sendfile syscalls completed without I/O request 0 requests for I/O initiated by sendfile 0 pages read by sendfile as part of a request 0 pages were valid at time of a sendfile request 0 pages were requested for read ahead by applications 0 pages were read ahead by sendfile 0 times sendfile encountered an already busy page 0 requests for sfbufs denied 0 requests for sfbufs delayed I did not perform any mbufs tuning, numbers above are from FreeBSD itself. This server has 64GB of memory. It has a ZFS pool for which I limit ARC memory impact with : vfs.zfs.arc_max=64424509440 #60G The only thing I did is some TCP tuning to improve throughput over high-latency long-distance private links : kern.ipc.maxsockbuf=7372800 net.inet.tcp.sendbuf_max=6553600 net.inet.tcp.recvbuf_max=6553600 net.inet.tcp.sendspace=65536 net.inet.tcp.recvspace=65536 net.inet.tcp.sendbuf_inc=65536 net.inet.tcp.recvbuf_inc=65536 net.inet.tcp.cc.algorithm=htcp Here are some graphs of memory & ARC usage when issue occurs. Crosshair (vertical red line) is at the timestamp where I get iSCSI disconnections. https://postimg.org/gallery/1kkekrc4e/ What is strange is that each time issue occurs there is around 1GB of free memory. So FreeBSD should still be able to allocate some more mbufs ? Unfortunately I do not have graphs about mbufs. What should I ideally do ? >> Have you tried increasing the mbufs limit? (sysctl) kern.ipc.nmbufs (Maximum number of mbufs allowed) Thank you again, Best regards, Ben > On 01 Jan 2017, at 09:16, Meny Yossefi <me...@mellanox.com> wrote: > > Hi Ben, > > Those are not HW errors, note that: > > hw.mlxen1.stat.rx_dropped: 0 > hw.mlxen1.stat.rx_errors: 0 > > It seems to be triggered when you are failing to allocate a replacement > buffer. > Any chance you ran out of mbufs in the system? > > en_rx.c: > > mlx4_en_process_rx_cq(): > > mb = mlx4_en_rx_mb(priv, rx_desc, mb_list, length); > if (!mb) { > ring->errors++; > goto next; > } > > mlx4_en_rx_mb() à mlx4_en_complete_rx_desc(): > > /* Allocate a replacement page */ > if (mlx4_en_alloc_buf(priv, rx_desc, mb_list, nr)) > goto fail; > > -Meny _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
