On 24 Jan 2014, at 14:21, FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > On Fri, 24 Jan 2014 12:51:13 +0400 > Artyom Pervukhin <artyom@xxxxxxxxxx> wrote: > >> Can you please specify what linux distribution and libraries version >> are you using? > > Debian squeeze amd64. > >> Iʼm able to reproduce this bug on current tgt codebase (17222f2b00d29368da214e2d59cbc9e00f53606b) built on Debian wheezy amd64. Bug frequency increases with number of targets: >> >> >> 1000 targets (all loaded, as `tgtadm -C 0 --op show --mode target --tid 1000` shows target settings): >> >> root@sandbox:~ # for i in $(seq 100) ; do tgtadm -C 0 --op show --mode target | grep -c ^Target ; done | sort | uniq -c >> 100 978 >> root@sandbox:~ # for i in $(seq 100) ; do tgtadm -C 0 --op show --mode target | wc -c ; done | sort | uniq -c >> 100 1033140 > > I can reproduce the same problem with 1000. > > root@rose:~# for i in $(seq 100); do tgtadm --op show --mode target|grep -c ^Target;done|sort|uniq -c > 97 1000 > 1 972 > 1 995 > 1 997 > > Strangely, looks like I can get the correct result without 'grep': > > root@rose:~# for i in $(seq 100); do tgtadm --op show --mode target|python -c "import sys; print len([line for line in sys.stdin if \"Target\" in line])";done|sort|uniq -c > 100 1000 > > I've done some additional stracing on the tgtd's side this time, please see below: Testing 300 targets: command: root@sandbox:~ # tgtadm -C 0 --op show --mode target (command shows full output) tgtd writes: write(10, "\0\0\0\0\305\325\4\0", 8) = 8 write(10, "Target 1: iqn.2014-01:d1\n Sys"..., 316861) = 224000 write(10, " State: ready\n I_T nexu"..., 92861) = 92861 command: root@sandbox:~ # tgtadm -C 0 --op show --mode target | wc -c 316860 tgtd writes stays the same as above. Testing 900 targets: root@sandbox:~ # tgtadm -C 0 --op show --mode target (command shows incomplete output) tgtd writes: write(10, "\0\0\0\0u\205\16\0", 8) = 8 write(10, "Target 1: iqn.2014-01:d1\n Sys"..., 951661) = 256000 write(10, "a: No\n Prevent remova"..., 695661) = 176000 write(10, " Removable media: No\n "..., 519661) = 176000 write(10, "T nexus information:\n LUN inf"..., 343661) = 176000 write(10, " Backing store path: None\n "..., 167661) = 167661 command: root@sandbox:~ # tgtadm -C 0 --op show --mode target | wc -c 929621 tgtd writes: write(10, "\0\0\0\0u\205\16\0", 8) = 8 write(10, "Target 1: iqn.2014-01:d1\n Sys"..., 951661) = 944000 write(10, "t removal: No\n Readon"..., 7661) = -1 EPIPE (Broken pipe) --- SIGPIPE (Broken pipe) @ 0 (0) --- Seeing this, I assumed the bug is on tgtadm's side. I've written a small program which sends exactly the same command as tgtadm does to tgtd's socket, then reads response back, dumping it to stdout (sorry it's in Go, my C ain't good: http://play.golang.org/p/EcFTboCncF). Dumping output like this I have no problem receiving full targets list: root@sandbox:~ # for i in $(seq 1000) ; do ./dump | wc -c ; done | sort | uniq -c 1000 951660 root@sandbox:~ # for i in $(seq 1000) ; do ./dump | grep -c ^Target ; done | sort | uniq -c 1000 900 Whereas tgtadm shows incomplete output: root@sandbox:~ # for i in $(seq 1000) ; do tgtadm -C 0 --op show --mode target | wc -c ; done | sort | uniq -c 1000 929621 root@sandbox:~ # for i in $(seq 1000) ; do tgtadm -C 0 --op show --mode target | grep -c ^Target ; done | sort | uniq -c 1000 880 -- Best regards, Artyom-- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
