Hi, I use: ipset v2.2.9a iptables 1.3.6 on kernel 2.6.19.7 (from kernel.org) on FC6. All has been compiled as said (http://ipset.netfilter.org/install.html ) This behaviour seems to happen where there are lots of bindings. I've got some questions : 1/ How to find optimal parameters for hashsize,probes , and resize ? (where we've got lot of bindings ..) I've got such errors in my /var/log/messages (but applying the command is ok !) Mar 26 17:22:27 iriafwa01 kernel: BUG: sleeping function called from invalid context at mm/slab.c:3007 Mar 26 17:22:27 iriafwa01 kernel: in_atomic():1, irqs_disabled():0 Mar 26 17:22:27 iriafwa01 kernel: [<c0158f10>] kmem_cache_alloc+0x1b/0x55 Mar 26 17:22:27 iriafwa01 kernel: [<f897c7c7>] ip_set_hash_add+0xf3/0x14a [ip_set] Mar 26 17:22:27 iriafwa01 kernel: [<f897d678>] ip_set_sockfn_get+0x9a8/0xab5 [ip_set] Mar 26 17:22:27 iriafwa01 kernel: [<c02f9bc4>] _read_unlock_irq+0x5/0x7 Mar 26 17:22:27 iriafwa01 kernel: [<c01150e1>] __wake_up+0x32/0x43 Mar 26 17:22:27 iriafwa01 kernel: [<c02b2264>] nf_sockopt+0x64/0xe2 Mar 26 17:22:27 iriafwa01 kernel: [<c02b2302>] nf_getsockopt+0x20/0x25 Mar 26 17:22:27 iriafwa01 kernel: [<c02bcb49>] ip_getsockopt+0x549/0x583 Mar 26 17:22:27 iriafwa01 kernel: [<c0141595>] do_generic_mapping_read+0x414/0x45b Mar 26 17:22:27 iriafwa01 kernel: [<c014328d>] generic_file_aio_read+0x17f/0x1ca Mar 26 17:22:27 iriafwa01 kernel: [<c0140a60>] file_read_actor+0x0/0xdb Mar 26 17:22:27 iriafwa01 kernel: [<c01cfd40>] vsnprintf+0x450/0x48c Mar 26 17:22:27 iriafwa01 kernel: [<c017fd54>] inotify_d_instantiate+0x44/0x72 Mar 26 17:22:27 iriafwa01 kernel: [<c016a4eb>] d_rehash+0x26/0x32 Mar 26 17:22:27 iriafwa01 kernel: [<c0292a0d>] sock_attach_fd+0x72/0xd5 Mar 26 17:22:27 iriafwa01 kernel: [<c0294226>] sock_common_getsockopt+0x1d/0x22 Mar 26 17:22:27 iriafwa01 kernel: [<c02927ee>] sys_getsockopt+0x7d/0x9c Mar 26 17:22:27 iriafwa01 kernel: [<c029401a>] sys_socketcall+0x22a/0x261 Mar 26 17:22:27 iriafwa01 kernel: [<c0102b05>] sysenter_past_esp+0x56/0x79 Mar 26 17:22:27 iriafwa01 kernel: [<c02f007b>] xfrm_add_pol_expire+0x26/0x14e Mar 26 17:22:27 iriafwa01 kernel: ======================= ipset -R < ipsets where ipsets is : # Generated by ipset 2.2.9a on Mon Mar 26 17:41:02 2007 -N ADM_SET1 iphash --hashsize 1024 --probes 4 --resize 25 -A ADM_SET1 192.168.50.66 -A ADM_SET1 192.168.50.67 -A ADM_SET1 192.168.50.10 -A ADM_SET1 192.168.50.1 -A ADM_SET1 192.168.50.64 -A ADM_SET1 192.168.50.11 -A ADM_SET1 192.168.50.70 -A ADM_SET1 192.168.50.34 -A ADM_SET1 192.168.50.68 -A ADM_SET1 192.168.50.97 -A ADM_SET1 192.168.50.65 -A ADM_SET1 192.168.50.12 -A ADM_SET1 192.168.50.71 -A ADM_SET1 192.168.50.98 -A ADM_SET1 192.168.50.69 -A ADM_SET1 192.168.50.3 -A ADM_SET1 192.168.50.33 -N ADM_SET2 iphash --hashsize 1024 --probes 4 --resize 25 -A ADM_SET2 192.168.51.26 -A ADM_SET2 192.168.50.45 -B ADM_SET1 192.168.50.98 -b ADM_SET2 -B ADM_SET1 192.168.50.34 -b ADM_SET2 -B ADM_SET1 192.168.50.1 -b ADM_SET2 -B ADM_SET1 192.168.50.64 -b ADM_SET2 -B ADM_SET1 192.168.50.71 -b ADM_SET2 -B ADM_SET1 192.168.50.97 -b ADM_SET2 -B ADM_SET1 192.168.50.3 -b ADM_SET2 -B ADM_SET1 192.168.50.65 -b ADM_SET2 -B ADM_SET1 192.168.50.11 -b ADM_SET2 -B ADM_SET1 192.168.50.69 -b ADM_SET2 -B ADM_SET1 192.168.50.67 -b ADM_SET2 -B ADM_SET1 192.168.50.66 -b ADM_SET2 -B ADM_SET1 192.168.50.33 -b ADM_SET2 -B ADM_SET1 192.168.50.70 -b ADM_SET2 -B ADM_SET1 192.168.50.12 -b ADM_SET2 -B ADM_SET1 192.168.50.68 -b ADM_SET2 -B ADM_SET1 192.168.50.10 -b ADM_SET2 COMMIT # Completed on Mon Mar 26 17:41:02 2007