I get up to and over 9% CPU usage when I've no sound playing application open - but I was playing sounds previously. Using perf, it appeared most CPU time being spent in kernel. strace gave me this output repeated continually:
ppoll([{fd=5, events=POLLIN}, {fd=22, events=POLLIN|POLLOUT}, {fd=49, events=POLLIN}, {fd=50, events=POLLIN}, {fd=48, events=POLLIN}, {fd=47, events=POLLIN}, {fd=10, events=POLLIN}, {fd=40, events=POLLIN}, {fd=35, events=POLLIN}, {fd=4, events=POLLIN}, {fd=42, events=POLLIN}, {fd=18, events=POLLIN}, {fd=21, events=POLLIN}, {fd=39, events=POLLIN}, {fd=38, events=POLLIN}, {fd=37, events=POLLIN}, {fd=36, events=POLLIN}, {fd=17, events=POLLIN}, {fd=34, events=POLLIN}, {fd=33, events=POLLIN}, {fd=32, events=POLLIN}, {fd=31, events=POLLIN|POLLERR|POLLHUP}, {fd=31, events=0}, {fd=25, events=POLLIN}, {fd=28, events=POLLIN}, {fd=16, events=POLLIN|POLLERR|POLLHUP}, {fd=16, events=0}, {fd=15, events=POLLIN}, {fd=14, events=POLLIN}, {fd=8, events=POLLIN}, {fd=7, events=POLLIN}], 31, NULL, NULL, 8) = 1 ([{fd=22, revents=POLLIN|POLLOUT}]) write(6, "W", 1) = 1 recvmsg(22, {msg_name(0)=NULL, msg_iov(1)=[{"\0\0\0\20\0\0\0\0\0\0\0\0\0\0\0\0\200\0\0\0", 20}], msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS{pid=3937, uid=1000, gid=1000}}, msg_flags=0}, 0) = 20 write(6, "W", 1) = 1 sendto(22, "\0\0\0\30\377\377\377\377\0\0\0\0\0\0\0\0\0\0\0\0L\0\0\0?L\377\377\377\377L\0"..., 44, MSG_NOSIGNAL, NULL, 0) = 44 write(6, "W", 1) = 1 read(5, "WWW", 10) = 3 ppoll([{fd=5, events=POLLIN}, {fd=22, events=POLLIN|POLLOUT}, {fd=49, events=POLLIN}, {fd=50, events=POLLIN}, {fd=48, events=POLLIN}, {fd=47, events=POLLIN}, {fd=10, events=POLLIN}, {fd=40, events=POLLIN}, {fd=35, events=POLLIN}, {fd=4, events=POLLIN}, {fd=42, events=POLLIN}, {fd=18, events=POLLIN}, {fd=21, events=POLLIN}, {fd=39, events=POLLIN}, {fd=38, events=POLLIN}, {fd=37, events=POLLIN}, {fd=36, events=POLLIN}, {fd=17, events=POLLIN}, {fd=34, events=POLLIN}, {fd=33, events=POLLIN}, {fd=32, events=POLLIN}, {fd=31, events=POLLIN|POLLERR|POLLHUP}, {fd=31, events=0}, {fd=25, events=POLLIN}, {fd=28, events=POLLIN}, {fd=16, events=POLLIN|POLLERR|POLLHUP}, {fd=16, events=0}, {fd=15, events=POLLIN}, {fd=14, events=POLLIN}, {fd=8, events=POLLIN}, {fd=7, events=POLLIN}], 31, NULL, NULL, 8) = 1 ([{fd=22, revents=POLLIN|POLLOUT}]) write(6, "W", 1) = 1 recvmsg(22, {msg_name(0)=NULL, msg_iov(1)=[{"\0\0\0\33\3\1\312\204\0002\0(\0\0\4\250", 16}], msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS{pid=3937, uid=1000, gid=1000}}, msg_flags=0}, 0) = 16 write(6, "W", 1) = 1 sendto(19, "\1\0\0\0\0\0\0\0", 8, MSG_NOSIGNAL, NULL, 0) = -1 ENOTSOCK (Socket operation on non-socket) write(19, "\1\0\0\0\0\0\0\0", 8) = 8 sendto(22, "\0\0\0\17\377\377\377\377\0\0\0\0\0\0\0\0\0\0\0\0L\0\0\0VL\377\377\377\377L\0"..., 35, MSG_NOSIGNAL, NULL, 0) = 35 write(6, "W", 1) = 1 read(5, "WWW", 10) = 3 What is PA continually polling?? -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/786831 Title: Pulseaudio uses 5% CPU when doing nothing Status in “pulseaudio” package in Ubuntu: Confirmed Bug description: Binary package hint: pulseaudio Pulseaudio is using five-percent CPU, with no sound playing and the inputs muted. This is eating the battery: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1601 sladen 20 0 175m 23m 21m S 5 0.8 3:11.78 pulseaudio clock_gettime(CLOCK_MONOTONIC, {17605, 365566885}) = 0 ppoll([{fd=4, events=POLLIN}, {fd=39, events=POLLIN|POLLOUT}, {fd=40, events=POLLIN}, {fd=38, events=POLLIN}, {fd=35, events=POLLIN}, {fd=21, events=POLLIN}, {fd=9, events=POLLIN}, {fd=37, events=POLLIN}, {fd=36, events=POLLIN}, {fd=27, events=POLLIN}, {fd=7, events=POLLIN}, {fd=20, events=POLLIN}, {fd=26, events=POLLIN}, {fd=34, events=POLLIN}, {fd=33, events=POLLIN}, {fd=32, events=POLLIN}, {fd=31, events=POLLIN}, {fd=30, events=POLLIN}, {fd=29, events=POLLIN|POLLERR|POLLHUP}, {fd=29, events=0}, {fd=22, events=POLLIN}, {fd=25, events=POLLIN}, {fd=16, events=POLLIN}, {fd=19, events=POLLIN}, {fd=15, events=POLLIN|POLLERR|POLLHUP}, {fd=15, events=0}, {fd=14, events=POLLIN}, {fd=13, events=POLLIN}, {fd=6, events=POLLIN}], 29, {3, 91527000}, NULL, 8) = 1 ([{fd=39, revents=POLLIN|POLLOUT}], left {3, 91511007}) clock_gettime(CLOCK_MONOTONIC, {17605, 367958597}) = 0 recvmsg(39, {msg_name(0)=NULL, msg_iov(1)=[{"\0\0\0\20\0\0\0\0\0\0\0\0\0\0\0\0\200\0\0\0", 20}], msg_controllen=24, {cmsg_len=24, cmsg_level=SOL_SOCKET, cmsg_type=SCM_CREDENTIALS{pid=12970, uid=1000, gid=1000}}, msg_flags=0}, 0) = 20 clock_gettime(CLOCK_MONOTONIC, {17605, 368566636}) = 0 ppoll([{fd=4, events=POLLIN}, {fd=39, events=POLLIN}, {fd=40, events=POLLIN}, {fd=38, events=POLLIN}, {fd=35, events=POLLIN}, {fd=21, events=POLLIN}, {fd=9, events=POLLIN}, {fd=37, events=POLLIN}, {fd=36, events=POLLIN}, {fd=27, events=POLLIN}, {fd=7, events=POLLIN}, {fd=20, events=POLLIN}, {fd=26, events=POLLIN}, {fd=34, events=POLLIN}, {fd=33, events=POLLIN}, {fd=32, events=POLLIN}, {fd=31, events=POLLIN}, {fd=30, events=POLLIN}, {fd=29, events=POLLIN|POLLERR|POLLHUP}, {fd=29, events=0}, {fd=22, events=POLLIN}, {fd=25, events=POLLIN}, {fd=16, events=POLLIN}, {fd=19, events=POLLIN}, {fd=15, events=POLLIN|POLLERR|POLLHUP}, {fd=15, events=0}, {fd=14, events=POLLIN}, {fd=13, events=POLLIN}, {fd=6, events=POLLIN}], 29, {3, 88527000}, NULL, 8) = 1 ([{fd=39, revents=POLLIN}], left {3, 88512333}) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/786831/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp