我查看了dmesg消息，但是看不太懂，把間隔比較大的幾段貼出來：（17.69秒到28.96秒，45秒到98秒）
[ 16.280941] audit: type=1130 audit(1450942724.676:64): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-udev-settle comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 16.281360] audit: type=1130 audit(1450942724.677:65): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-fsck@dev-disk-by\x2duuid-9ef9a9e6\x2d0a9a\x2d406e\x2db983\x2df961ad9bf64d comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 16.414021] audit: type=1130 audit(1450942724.809:66): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-rfkill@rfkill0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 16.719894] audit: type=1130 audit(1450942725.115:67): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-fsck@dev-disk-by\x2duuid-CEEE\x2d4949 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 16.848056] audit: type=1130 audit(1450942725.243:68): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=dmraid-activation comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 16.848110] audit: type=1131 audit(1450942725.243:69): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=dmraid-activation comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 16.891764] EXT4-fs (sda2): mounted filesystem with ordered data mode. Opts: (null)
[ 16.993826] audit: type=1130 audit(1450942725.389:70): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-fsck@dev-disk-by\x2duuid-65459c95\x2d6d35\x2d4977\x2dbb74\x2d99e0f60fa80b comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 17.403613] EXT4-fs (sda5): mounted filesystem with ordered data mode. Opts: (null)
[ 17.567164] audit: type=1130 audit(1450942725.962:71): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=nfs-config comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 17.693347] audit: type=1130 audit(1450942726.088:72): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=dracut-shutdown comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 28.964907] nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
[ 29.201034] ip6_tables: (C) 2000-2006 Netfilter Core Team
[ 30.033773] Ebtables v2.0 registered
[ 30.313792] bridge: automatic filtering via arp/ip/ip6tables has been deprecated. Update your scripts to load br_netfilter if you need this.
[ 36.400766] IPv6: ADDRCONF(NETDEV_UP): eno1: link is not ready
[ 36.608428] r8169 0000:08:00.0 eno1: link down
[ 36.608514] IPv6: ADDRCONF(NETDEV_UP): eno1: link is not ready
[ 36.611293] IPv6: ADDRCONF(NETDEV_UP): wlo1: link is not ready
[ 37.013733] IPv6: ADDRCONF(NETDEV_UP): wlo1: link is not ready
[ 37.774904] IPv6: ADDRCONF(NETDEV_UP): wlo1: link is not ready
[ 38.718088] wlo1: authenticate with 6c:e8:73:f9:54:d2
[ 38.728323] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 1/3)
[ 38.928705] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 2/3)
[ 39.129798] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 3/3)
[ 39.330985] wlo1: authentication with 6c:e8:73:f9:54:d2 timed out
[ 40.358269] wlo1: authenticate with 6c:e8:73:f9:54:d2
[ 40.376166] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 1/3)
[ 40.576755] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 2/3)
[ 40.777854] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 3/3)
[ 40.979030] wlo1: authentication with 6c:e8:73:f9:54:d2 timed out
[ 42.406331] wlo1: authenticate with 6c:e8:73:f9:54:d2
[ 42.424432] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 1/3)
[ 42.625109] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 2/3)
[ 42.826155] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 3/3)
[ 43.027281] wlo1: authentication with 6c:e8:73:f9:54:d2 timed out
[ 44.954940] wlo1: authenticate with 6c:e8:73:f9:54:d2
[ 44.973991] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 1/3)
[ 45.174662] wlo1: direct probe to 6c:e8:73:f9:54:d2 (try 2/3)
[ 45.375778] wlo1: send auth to 6c:e8:73:f9:54:d2 (try 3/3)
[ 45.377083] wlo1: authenticated
[ 45.377784] wlo1: associate with 6c:e8:73:f9:54:d2 (try 1/3)
[ 45.381289] wlo1: RX AssocResp from 6c:e8:73:f9:54:d2 (capab=0x431 status=0 aid=5)
[ 45.381569] wlo1: associated
[ 45.381583] IPv6: ADDRCONF(NETDEV_CHANGE): wlo1: link becomes ready
[ 53.411673] fuse init (API version 7.23)
[ 98.650216] [drm] probing gen 2 caps for device 8086:151 = 261ac83/e
[ 98.650223] [drm] PCIE gen 3 link speeds already enabled
[ 98.655399] [drm] PCIE GART of 2048M enabled (table at 0x0000000000040000).
[ 98.655516] radeon 0000:01:00.0: WB enabled
[ 98.655521] radeon 0000:01:00.0: fence driver on ring 0 use gpu addr 0x0000000040000c00 and cpu addr 0xffff880157528c00
[ 98.655524] radeon 0000:01:00.0: fence driver on ring 1 use gpu addr 0x0000000040000c04 and cpu addr 0xffff880157528c04
[ 98.655527] radeon 0000:01:00.0: fence driver on ring 2 use gpu addr 0x0000000040000c08 and cpu addr 0xffff880157528c08
[ 98.655529] radeon 0000:01:00.0: fence driver on ring 3 use gpu addr 0x0000000040000c0c and cpu addr 0xffff880157528c0c
[ 98.655532] radeon 0000:01:00.0: fence driver on ring 4 use gpu addr 0x0000000040000c10 and cpu addr 0xffff880157528c10
[ 98.655535] radeon 0000:01:00.0: VCE init error (-22).
[ 98.795578] [drm] ring test on 0 succeeded in 1 usecs
[ 98.795582] [drm] ring test on 1 succeeded in 1 usecs
[ 98.795585] [drm] ring test on 2 succeeded in 1 usecs
[ 98.795592] [drm] ring test on 3 succeeded in 3 usecs
[ 98.795597] [drm] ring test on 4 succeeded in 3 usecs
[ 98.795623] [drm] ib test on ring 0 succeeded in 0 usecs
[ 98.795644] [drm] ib test on ring 1 succeeded in 0 usecs
[ 98.795665] [drm] ib test on ring 2 succeeded in 0 usecs
[ 98.795682] [drm] ib test on ring 3 succeeded in 0 usecs
[ 98.795694] [drm] ib test on ring 4 succeeded in 0 usecs
後面一個看上去是網絡延遲造成的。給網卡分配靜態ip，拔掉網線，禁用不必要的服務看看。
