Hi! I'm testing kernel-git (git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git , at 07f00f06ba9a5533d6650d46d3e938f6cbeee97e ) because I noticed strange OOM behavior in kernel 4.7.0. As for now I can't reproduce problems with OOM, probably it's fixed now. But now I wanted to try z3fold with zswap. When I did `echo z3fold > /sys/module/zswap/parameters/zpool` I got trace from dmesg: [ 429.722411] ------------[ cut here ]------------ [ 429.723476] WARNING: CPU: 0 PID: 5140 at mm/zswap.c:503 __zswap_pool_current+0x56/0x60 [ 429.725161] Modules linked in: z3fold tun algif_skcipher af_alg dm_crypt netconsole xt_policy ipt_REJECT nf_reject_ipv4 xt_TARPIT(OE) xt_NFLOG ip_set_hash_ip ip_set_hash_net xt_SYSRQ(OE) xt_multiport nfnetlink_queue sit ip_tunnel tunnel4 xt_set ip_set iptable_filter xt_nat xt_comment xt_length iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat iptable_mangle xt_CT iptable_raw ip_tables nf_conntrack_ipv6 nf_defrag_ipv6 ip6t_rt xt_conntrack nf_conntrack ip6table_filter ip6table_mangle ip6_tables ipv6 xfs libcrc32c btrfs xor zlib_deflate raid6_pq tcp_diag inet_diag aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd button virtio_net virtio_balloon crc32c_intel [ 429.738937] CPU: 0 PID: 5140 Comm: bash Tainted: G OE 4.7.0+ #4 [ 429.739880] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 [ 429.740048] 0000000000000286 000000002ea2eeca ffff8ecca91efcd8 ffffffffad255d43 [ 429.740048] 0000000000000000 0000000000000000 ffff8ecca91efd18 ffffffffad04c997 [ 429.740048] 000001f700000003 ffffffffad9b8a58 ffff8eccbd162b58 0000000000000000 [ 429.740048] Call Trace: [ 429.740048] [<ffffffffad255d43>] dump_stack+0x63/0x90 [ 429.740048] [<ffffffffad04c997>] __warn+0xc7/0xf0 [ 429.740048] [<ffffffffad04cac8>] warn_slowpath_null+0x18/0x20 [ 429.740048] [<ffffffffad1250c6>] __zswap_pool_current+0x56/0x60 [ 429.740048] [<ffffffffad1250e3>] zswap_pool_current+0x13/0x20 [ 429.740048] [<ffffffffad125efb>] __zswap_param_set+0x1db/0x2f0 [ 429.740048] [<ffffffffad126042>] zswap_zpool_param_set+0x12/0x20 [ 429.740048] [<ffffffffad06645f>] param_attr_store+0x5f/0xc0 [ 429.740048] [<ffffffffad065b69>] module_attr_store+0x19/0x30 [ 429.740048] [<ffffffffad1b0b02>] sysfs_kf_write+0x32/0x40 [ 429.740048] [<ffffffffad1b0663>] kernfs_fop_write+0x113/0x190 [ 429.740048] [<ffffffffad13fc52>] __vfs_write+0x32/0x150 [ 429.740048] [<ffffffffad15f0ae>] ? __fd_install+0x2e/0xe0 [ 429.740048] [<ffffffffad15ef11>] ? __alloc_fd+0x41/0x180 [ 429.740048] [<ffffffffad0838dd>] ? percpu_down_read+0xd/0x50 [ 429.740048] [<ffffffffad140d33>] vfs_write+0xb3/0x1a0 [ 429.740048] [<ffffffffad13db81>] ? filp_close+0x51/0x70 [ 429.740048] [<ffffffffad142140>] SyS_write+0x50/0xc0 [ 429.740048] [<ffffffffad413836>] entry_SYSCALL_64_fastpath+0x1e/0xa8 [ 429.764069] ---[ end trace ff7835fbf4d983b9 ]--- Second issue: Since 4.7.0 up to now I've got strange problem with starting BIND (dns). It can't start, throws: 2016-08-01T10:42:21.449188+02:00 jowisz named[3730]: listening on IPv4 interface eth0, 81.4.122.249#53 2016-08-01T10:42:21.449412+02:00 jowisz named[3730]: could not listen on UDP socket: out of memory 2016-08-01T10:42:21.449455+02:00 jowisz named[3730]: creating IPv4 interface eth0 failed; interface ignored 2016-08-01T10:42:21.449514+02:00 jowisz named[3730]: not listening on any interfaces 2016-08-01T10:42:21.449670+02:00 jowisz named[3730]: generating session key for dynamic DNS 2016-08-01T10:42:21.449910+02:00 jowisz named[3730]: sizing zone task pool based on 69 zones 2016-08-01T10:42:21.450094+02:00 jowisz named[3730]: dns_master_load: out of memory 2016-08-01T10:42:21.450668+02:00 jowisz named[3730]: could not configure root hints from 'named.cache': out of memory 2016-08-01T10:42:21.451236+02:00 jowisz named[3730]: additionally listening on IPv4 interface eth0, 81.4.122.249#53 2016-08-01T10:42:21.451298+02:00 jowisz named[3730]: could not listen on UDP socket: out of memory 2016-08-01T10:42:21.451342+02:00 jowisz named[3730]: creating IPv4 interface eth0 failed; interface ignored 2016-08-01T10:42:21.451479+02:00 jowisz named[3730]: loading configuration: out of memory 2016-08-01T10:42:21.451515+02:00 jowisz named[3730]: exiting (due to fatal error) strace shows: [pid 26247] sendto(3, "<29>Aug 1 11:02:23 named[26230]"..., 80, MSG_NOSIGNAL, NULL, 0) = 80 [pid 26247] mprotect(0x7f8828051000, 8192, PROT_READ|PROT_WRITE) = -1 ENOMEM (Cannot allocate memory) [pid 26247] mmap(NULL, 134217728, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = 0x7f8820000000 [pid 26247] munmap(0x7f8824000000, 67108864) = 0 [pid 26247] mprotect(0x7f8820000000, 143360, PROT_READ|PROT_WRITE) = -1 ENOMEM (Cannot allocate memory) [pid 26247] munmap(0x7f8820000000, 67108864) = 0 [pid 26247] mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate memory) [pid 26247] mprotect(0x7f8828051000, 8192, PROT_READ|PROT_WRITE) = -1 ENOMEM (Cannot allocate memory) [pid 26247] mmap(0x7f8824000000, 67108864, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = 0x7f8824000000 [pid 26247] mprotect(0x7f8824000000, 143360, PROT_READ|PROT_WRITE) = -1 ENOMEM (Cannot allocate memory) [pid 26247] munmap(0x7f8824000000, 67108864) = 0 Thanks, Marcin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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