Re: sendfile to nonblocking socket

From: Alex Vorona
Date: Tue Apr 24 2007 - 00:44:05 EST

David Miller wrote:
From: voron <voron@xxxxxxxxxx>
Date: Tue, 24 Apr 2007 00:13:27 +0300

As I see, nonblocking mode is enabled - sendfile sends less than asked.

The socket is marked as non-blocking, but the disk I/O is not.

It's blocking on the disk I/O not the socket part of the operation.


How can I told kernel to not block on disk I/O? I tried non-blocking on
disk i/o fd, but it seems to be ignored. Strace with both nonblocing
disk fd and socket fd in attach
#non-blocking on socket fd enabled
04:34:07 ioctl(9, FIONBIO, [1]) = 0
#non-blocking on disk fd enabled
04:34:11 ioctl(12, FIONBIO, [1]) = 0
#normal sendfile
04:34:07 sendfile(9, 12, [444282], 2147477638) = 812682
#32 seconds sendfile
04:34:11 sendfile(9, 12, [261474962], 2147476846) = 2144612230

Thank you,
Alex

04:34:04 write(3, "2007/04/24 04:34:04 [info] 32390"..., 85) = 85
04:34:04 epoll_wait(11, {{EPOLLIN, {u32=3618562064, u64=61614924423184}}}, 512, 4294967295) = 1
04:34:07 accept(8, {sa_family=AF_INET, sin_port=htons(52673), sin_addr=inet_addr("192.168.78.1")}, [5056848310527066128]) = 9
04:34:07 ioctl(9, FIONBIO, [1]) = 0
04:34:07 epoll_ctl(11, EPOLL_CTL_ADD, 9, {EPOLLIN|EPOLLET, {u32=3618562369, u64=61614924423489}}) = 0
04:34:07 epoll_wait(11, {{EPOLLIN, {u32=3618562369, u64=61614924423489}}}, 512, 600000) = 1
04:34:07 recvfrom(9, "GET /3.tmp HTTP/1.0\r\nUser-Agent:"..., 1024, 0, NULL, NULL) = 147
04:34:07 open("/var/www/cacti/htdocs/3.tmp", O_RDONLY) = 12
04:34:07 fstat(12, {st_mode=S_IFREG|0644, st_size=4294967296, ...}) = 0
04:34:07 setsockopt(9, SOL_TCP, TCP_CORK, [1], 4) = 0
04:34:07 writev(9, [{"HTTP/1.1 200 OK\r\nServer: nginx/0"..., 262}], 1) = 262
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [0], 2147475456) = 20576
04:34:07 epoll_ctl(11, EPOLL_CTL_MOD, 9, {EPOLLIN|EPOLLOUT|EPOLLET, {u32=3618562369, u64=61614924423489}}) = 0
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 600000) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [20576], 2147479456) = 55568
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599975) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [76144], 2147477136) = 41676
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599973) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [117820], 2147476420) = 83352
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599972) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [201172], 2147479084) = 243110
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599971) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [444282], 2147477638) = 812682
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599968) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [1256964], 2147475964) = 7501680
04:34:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599950) = 1
04:34:07 ioctl(12, FIONBIO, [1]) = 0
04:34:07 sendfile(9, 12, [8758644], 2147478156) = 234274688
04:34:10 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599846) = 1
04:34:10 ioctl(12, FIONBIO, [1]) = 0
04:34:10 sendfile(9, 12, [243033332], 2147478284) = 583464
04:34:10 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 600000) = 1
04:34:10 ioctl(12, FIONBIO, [1]) = 0
04:34:10 sendfile(9, 12, [243616796], 2147476452) = 16712076
04:34:11 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599990) = 1
04:34:11 ioctl(12, FIONBIO, [1]) = 0
04:34:11 sendfile(9, 12, [260328872], 2147476056) = 1146090
04:34:11 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599766) = 1
04:34:11 ioctl(12, FIONBIO, [1]) = 0
04:34:11 sendfile(9, 12, [261474962], 2147476846) = 2144612230
04:34:43 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599754) = 1
04:34:43 ioctl(12, FIONBIO, [1]) = 0
04:34:43 sendfile(9, 12, [2406087192], 1888880104) = 611248
04:34:43 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 600000) = 1
04:34:43 ioctl(12, FIONBIO, [1]) = 0
04:34:43 sendfile(9, 12, [2406698440], 1888268856) = 1000890816
04:34:57 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599991) = 1
04:34:57 ioctl(12, FIONBIO, [1]) = 0
04:34:57 sendfile(9, 12, [3407589256], 887378040) = 972440
04:34:58 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 600000) = 1
04:34:58 ioctl(12, FIONBIO, [1]) = 0
04:34:58 sendfile(9, 12, [3408561696], 886405600) = 861304
04:34:58 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599977) = 1
04:34:58 ioctl(12, FIONBIO, [1]) = 0
04:34:58 sendfile(9, 12, [3409423000], 885544296) = 993278
04:34:58 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599954) = 1
04:34:58 ioctl(12, FIONBIO, [1]) = 0
04:34:58 sendfile(9, 12, [3410416278], 884551018) = 847412
04:34:58 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599930) = 1
04:34:58 ioctl(12, FIONBIO, [1]) = 0
04:34:58 sendfile(9, 12, [3411263690], 883703606) = 4021734
04:34:58 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599908) = 1
04:34:58 ioctl(12, FIONBIO, [1]) = 0
04:34:58 sendfile(9, 12, [3415285424], 879681872) = 492166998
04:35:07 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 599874) = 1
04:35:07 ioctl(12, FIONBIO, [1]) = 0
04:35:07 sendfile(9, 12, [3907452422], 387514874) = 104002458
04:35:09 epoll_wait(11, {{EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 600000) = 1
04:35:09 ioctl(12, FIONBIO, [1]) = 0
04:35:09 sendfile(9, 12, [4011454880], 283512416) = 283512416
04:35:15 write(6, "192.168.78.1 - voron [24/Apr/200"..., 114) = 114
04:35:15 close(12) = 0
04:35:15 setsockopt(9, SOL_TCP, TCP_CORK, [0], 4) = 0
04:35:15 recvfrom(9, 0x5804d0, 1024, 0, 0, 0) = -1 EAGAIN (Resource temporarily unavailable)
04:35:15 epoll_wait(11, {{EPOLLIN|EPOLLOUT, {u32=3618562369, u64=61614924423489}}}, 512, 75000) = 1
04:35:15 recvfrom(9, "", 1024, 0, NULL, NULL) = 0
04:35:15 close(9) = 0
04:35:15 epoll_wait(11,