Hi, When I transfer large files at high speed(rsync to my x86 router, locally, not trough the Internet) I get: ping: sendmsg: No buffer space available And I can't send anymore data. /sys/kernel/debug/ieee80211/phy*/queues is 00: 0x00000000/0 01: 0x00000000/0 02: 0x00000000/0 03: 0x00000000/0 In normal conditions. But when I can't send anymore data I've that: 00: 0x00000000/0 01: 0x00000000/0 02: 0x00000001/0 03: 0x00000000/0 or that: 00: 0x00000000/0 01: 0x00000000/0 02: 0x00000001/333 03: 0x00000000/0 Here's my irc conversation in #linux-wireless on Freeenode about that issue: Feb 22 16:28:38 <GNUtoo|laptop> hi, Feb 22 16:29:23 <GNUtoo|laptop> when I rsync to my router at high speed over wifi, huge amount of data, I've that: Feb 22 16:29:24 <GNUtoo|laptop> ping: sendmsg: No buffer space available Feb 22 16:29:27 <GNUtoo|laptop> and wifi breaks Feb 22 16:29:30 <GNUtoo|laptop> I've to reconnect Feb 22 16:29:40 <GNUtoo|laptop> should I try setting a lower MTU? Feb 22 16:29:43 <GNUtoo|laptop> what should I try? Feb 22 16:29:53 <GNUtoo|laptop> and why isn't there any more buffer space? Feb 22 16:31:57 <johill> sounds like a queue management bug Feb 22 16:32:06 <johill> with packets stuck somewhere Feb 22 16:32:09 <johill> what driver? Feb 22 16:34:04 * an-t (~ant@xxxxxxxxxxxxx) has joined #linux-wireless Feb 22 16:34:42 <GNUtoo|laptop> ath9k Feb 22 16:34:51 <GNUtoo|laptop> on 2.6.37-020637-generic Feb 22 16:34:57 <GNUtoo|laptop> I think that's mainline Feb 22 16:35:01 <GNUtoo|laptop> let me check Feb 22 16:35:02 <johill> hm, dunno Feb 22 16:35:09 <johill> there were some queue mgmt things there Feb 22 16:35:12 <johill> don't really konw Feb 22 16:35:49 <Chainsaw> GNUtoo|laptop: Probably useful to share your driver DDoS on linux-wireless; some idea of how many files & what size. Feb 22 16:36:10 <GNUtoo|laptop> basically what I do is that: Feb 22 16:36:20 <GNUtoo|laptop> I use openembedded to cross-compile files Feb 22 16:36:25 <GNUtoo|laptop> and sync the result with my router Feb 22 16:36:26 * Blues-Man (~bluesman@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) has joined #linux-wireless Feb 22 16:36:35 <GNUtoo|laptop> that is an x86 computer with ath9k and hostapd Feb 22 16:36:52 <GNUtoo|laptop> cd /home/gnutoo/embedded/oe/oetmps/eee701/deploy/glibc Feb 22 16:36:56 <GNUtoo|laptop> rsync -av -e "ssh -l gnutoo -p 222" * router:/var/www/gnutoo.homelinux.org/openembedded/eee701 Feb 22 16:37:05 <GNUtoo|laptop> is the script I use to sync it Feb 22 16:37:37 <johill> I bet when this happens you never get a ping pcket through Feb 22 16:38:10 <johill> and /sys/kernel/debug/ieee80211/phy*/queues is non-zero Feb 22 16:38:18 <johill> the info from that file would be useful Feb 22 16:38:37 <GNUtoo|laptop> ok I was pastebining the file sizes Feb 22 16:38:41 <GNUtoo|laptop> as there are a lot of files.... Feb 22 16:39:06 <GNUtoo|laptop> ok I'll try to reproduce Feb 22 16:39:13 <GNUtoo|laptop> tough that will disconnect me from irc Feb 22 16:40:54 <johill> I bet it'll be 0x0001/n Feb 22 16:40:56 <johill> n > 0 Feb 22 16:42:16 <GNUtoo|laptop> ping also increase during the huge transfer Feb 22 16:42:30 <johill> that's "bufferbloat" but expected now Feb 22 16:42:35 <GNUtoo|laptop> ok Feb 22 16:42:49 <GNUtoo|laptop> I learned what bufferbloat was not so long ago Feb 22 16:44:27 * Topic for #linux-wireless is: User-level discussions about wireless LANs on Linux | compat-wireless-2.6 only available for kernels >= 2.6.27, work is underway to enable older kernels now that we don't use multiqueue on mac80211 Feb 22 16:44:27 * Topic for #linux-wireless set by linville at Wed Jul 8 21:06:20 2009 Feb 22 16:44:30 <GNUtoo|laptop> it starts with Feb 22 16:44:32 <GNUtoo|laptop> 02: 0x00000001/0 Feb 22 16:44:41 <GNUtoo|laptop> and then increase to Feb 22 16:44:47 <GNUtoo|laptop> 02: 0x00000001/333 Feb 22 16:44:50 <GNUtoo|laptop> the reset is 0 Feb 22 16:45:02 <johill> yeah Feb 22 16:45:06 <johill> as expected Feb 22 16:45:08 <GNUtoo|laptop> ok Feb 22 16:45:12 <GNUtoo|laptop> what's that exactly? Feb 22 16:45:19 <johill> the reason why the queue is stopped Feb 22 16:45:23 <johill> and the number of packets in the queue Feb 22 16:45:24 <GNUtoo|laptop> oh nice Feb 22 16:45:32 <johill> 0x000 == not stopped Feb 22 16:45:35 <GNUtoo|laptop> ok Feb 22 16:45:39 <GNUtoo|laptop> and what's the reason? Feb 22 16:45:41 <johill> /0 = no packets Feb 22 16:45:54 <johill> BIT(0) == driver asked for queue to be stopped Feb 22 16:46:03 <johill> (IEEE80211_QUEUE_STOP_REASON_DRIVER) Feb 22 16:46:08 <GNUtoo|laptop> ok Feb 22 16:46:11 <johill> (net/mac80211/ieee80211_i.h) Feb 22 16:46:15 <johill> so driver's fault Feb 22 16:46:28 <GNUtoo|laptop> dmesg shows nothing tough Feb 22 16:46:37 <GNUtoo|laptop> only normal stuff Feb 22 16:46:38 <johill> yeah not surprising either Feb 22 16:46:45 <GNUtoo|laptop> ah debugfs? Feb 22 16:46:47 <johill> queue start/stop happens often enough, no logging for it Feb 22 16:46:50 <GNUtoo|laptop> or something like that should be used Feb 22 16:46:50 <GNUtoo|laptop> ok Feb 22 16:49:45 <GNUtoo|laptop> what should I do now? Feb 22 16:50:10 <johill> report a bug on ath9k Denis. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
