Hello wireless-list!
Hello hostapd-list!
I am using ath5k with hostapd-0.6.9 on a debian running kernel 2.6.34
and I am observing a "ressource temporarily unavailable" - error code 11
if I pump out multicast-packets quite fast. I wrote a small
test-program, that handles this test and as soon as I go down to a
8ms-pause or below in betweens the packets, the error is thrown quite
soon after starting the program. Funny thing is, that this error only
occurs in g-band (2.4 GHz), not in a-band (5GHz).
What could be the problem? Is this due to backoff-times in 2.4 GHz, that
don't occur on 5 GHz? Or could this be a bug?
Find attached my small piece of code to test and reproduce this effect.
Kind regards,
Dennis
On Wed, Jun 16, 2010 at 04:05:49PM +0200, Dennis Borgmann wrote:
> Hello wireless-list!
> Hello hostapd-list!
>
> I am using ath5k with hostapd-0.6.9 on a debian running kernel 2.6.34
> and I am observing a "ressource temporarily unavailable" - error code 11
> if I pump out multicast-packets quite fast. I wrote a small
> test-program, that handles this test and as soon as I go down to a
> 8ms-pause or below in betweens the packets, the error is thrown quite
> soon after starting the program. Funny thing is, that this error only
> occurs in g-band (2.4 GHz), not in a-band (5GHz).
>
> What could be the problem? Is this due to backoff-times in 2.4 GHz, that
> don't occur on 5 GHz? Or could this be a bug?
My only initial thought is that the 2.5GHz band is usually more
utilized. So there is more likely to be retransmissions, etc.
> Find attached my small piece of code to test and reproduce this effect.
Perhaps you could include actual dmesg output?
John
--
John W. Linville Someday the world will need a hero, and you
[email protected] might be all we have. Be ready.
Okay, let's say, we have a crowded medium, lots of clients transmitting
traffic and therefore we have backoff times of around 50ms. Let's say,
we have such a backoff only ONCE(just for theoretical discussion) -
transmission of this packet would take at least 50ms. With the amount of
data I want to transmit in my example program, I am running at around
3,2 kbps, which is not that much(I send out 800 bytes each 2ms -> 800
bytes/2ms = 400 bytes/ms * 8 = 3,2 kbps). Now for 50ms there can be no
transmission due to the backoff time. The buffer of the wireless card -
or the buffer of the socket, I do not exactly know - gets filled 25
times with 800 byte-packets. That's in total 25 * 800 byte = 10000 byte.
So in this scenario, I would at least need a buffer 10kbyte of size. The
buffer of the socket should be sufficient, since an SO_SNDBUF call gives
114688 of size. That should be sufficient. Anyway, Wright and Stevens
(TCP/IP Illustrated Volume 2, Chapter 16.7 - "Unreliable Protocol
Buffering") state:
"With unreliable protocols (e.g. UDP), no data is ever stored in the
send buffer and no ACK is ever expected. Each message is passed
immediately to the protocol where it is queued for transmission on the
appropriate network device".
This tells me, that the driver buffer seems to be too small for this
frequency of packets (every 2ms) with this size (800 bytes), if I work
on a band, that is loaded with backoff times due to carrier sense
multiple access(CSMA). Is there a way to increase its size for ath5k?
Kind regards,
Dennis
Dennis Borgmann schrieb:
> Hey guys!
>
> I just reproduced the error with a transmit frequency of 4ms and dmesg
> doesn't show up with any new output. I will append dmesg to this mail
> anyway.
>
> Apart from that, I will go ahead and search for handling EAGAIN.
>
> Kind regards,
> Dennis
>
>
> Bob Copeland schrieb:
>
>> On Wed, Jun 16, 2010 at 10:05 AM, Dennis Borgmann
>> <[email protected]> wrote:
>>
>>
>>> Hello wireless-list!
>>> Hello hostapd-list!
>>>
>>> I am using ath5k with hostapd-0.6.9 on a debian running kernel 2.6.34
>>> and I am observing a "ressource temporarily unavailable" - error code 11
>>>
>>>
>> [...]
>>
>>
>>> What could be the problem? Is this due to backoff-times in 2.4 GHz, that
>>> don't occur on 5 GHz? Or could this be a bug?
>>>
>>>
>> Does dmesg report any error (e.g. no available txbuf)?
>>
>> My guess is you have more frequent successful delivery in 5 GHz than in
>> ISM band so you aren't running out of send buffers somewhere in the stack.
>>
>> Of course, your program should expect and handle EAGAIN if you are
>> using MSG_DONTWAIT.
>>
>>
>>
>
>
Linux version 2.6.34 (root@debian_DEV) (gcc version 4.3.2 (Debian 4.3.2-1.1) ) #1 PREEMPT Tue Jun 15 15:51:31 CEST 2010
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009e800 (usable)
BIOS-e820: 000000000009e800 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000000ffc0000 (usable)
BIOS-e820: 00000000ffff0000 - 0000000100000000 (reserved)
Notice: NX (Execute Disable) protection missing in CPU or disabled in BIOS!
DMI not present or invalid.
e820 update range: 0000000000000000 - 0000000000001000 (usable) ==> (reserved)
e820 remove range: 00000000000a0000 - 0000000000100000 (usable)
last_pfn = 0xffc0 max_arch_pfn = 0x100000
initial memory mapped : 0 - 00800000
init_memory_mapping: 0000000000000000-000000000ffc0000
0000000000 - 0000400000 page 4k
0000400000 - 000fc00000 page 2M
000fc00000 - 000ffc0000 page 4k
kernel direct mapping tables up to ffc0000 @ 7000-c000
RAMDISK: 0be27000 - 0c010000
255MB LOWMEM available.
mapped low ram: 0 - 0ffc0000
low ram: 0 - 0ffc0000
Zone PFN ranges:
DMA 0x00000001 -> 0x00001000
Normal 0x00001000 -> 0x0000ffc0
Movable zone start PFN for each node
early_node_map[2] active PFN ranges
0: 0x00000001 -> 0x0000009e
0: 0x00000100 -> 0x0000ffc0
On node 0 totalpages: 65373
free_area_init_node: node 0, pgdat c03ff584, node_mem_map c1000020
DMA zone: 32 pages used for memmap
DMA zone: 0 pages reserved
DMA zone: 3965 pages, LIFO batch:0
Normal zone: 480 pages used for memmap
Normal zone: 60896 pages, LIFO batch:15
Using APIC driver default
No local APIC present or hardware disabled
APIC: disable apic facility
APIC: switched to apic NOOP
nr_irqs_gsi: 16
Allocating PCI resources starting at ffc0000 (gap: ffc0000:f0030000)
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 64861
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-2.6.34 root=UUID=a085012f-0fc3-4a20-901c-0b4794889335 ro
PID hash table entries: 1024 (order: 0, 4096 bytes)
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Initializing CPU#0
Subtract (21 early reservations)
#0 [0000100000 - 000045ece0] TEXT DATA BSS
#1 [000be27000 - 000c010000] RAMDISK
#2 [000009e000 - 0000100000] BIOS reserved
#3 [000045f000 - 0000461000] BRK
#4 [0000007000 - 0000008000] PGTABLE
#5 [0001000000 - 0001200000] BOOTMEM
#6 [0001200000 - 0001200004] BOOTMEM
#7 [0001200040 - 00012000c0] BOOTMEM
#8 [00012000c0 - 00012000d8] BOOTMEM
#9 [0001200100 - 0001200900] BOOTMEM
#10 [0001200900 - 00012009a8] BOOTMEM
#11 [00012009c0 - 0001200a00] BOOTMEM
#12 [0001200a00 - 0001200a40] BOOTMEM
#13 [0001200a40 - 0001200a80] BOOTMEM
#14 [0001200a80 - 0001200ac0] BOOTMEM
#15 [0001200ac0 - 0001200b00] BOOTMEM
#16 [0001200b00 - 0001200b52] BOOTMEM
#17 [0001200b80 - 0001200bd2] BOOTMEM
#18 [0001200c00 - 0001201c00] BOOTMEM
#19 [0001201c00 - 0001221c00] BOOTMEM
#20 [0001221c00 - 0001231c00] BOOTMEM
Memory: 253824k/261888k available (2172k kernel code, 7668k reserved, 909k data, 240k init, 0k highmem)
virtual kernel memory layout:
fixmap : 0xfffa4000 - 0xfffff000 ( 364 kB)
vmalloc : 0xd07c0000 - 0xfffa2000 ( 759 MB)
lowmem : 0xc0000000 - 0xcffc0000 ( 255 MB)
.init : 0xc0403000 - 0xc043f000 ( 240 kB)
.data : 0xc031f2e1 - 0xc04027c0 ( 909 kB)
.text : 0xc0100000 - 0xc031f2e1 (2172 kB)
Checking if this processor honours the WP bit even in supervisor mode...Ok.
Experimental preemptable hierarchical RCU implementation.
NR_IRQS:288
Console: colour dummy device 80x25
console [tty0] enabled
Fast TSC calibration using PIT
Detected 498.049 MHz processor.
Calibrating delay loop (skipped), value calculated using timer frequency.. 996.09 BogoMIPS (lpj=498049)
Mount-cache hash table entries: 512
Performance Events: no PMU driver, software events only.
CPU: Geode(TM) Integrated Processor by AMD PCS stepping 02
Checking 'hlt' instruction... OK.
NET: Registered protocol family 16
PCI: PCI BIOS revision 2.10 entry at 0xfafc0, last bus=0
PCI: Using configuration type 1 for base access
bio: create slab <bio-0> at 0
vgaarb: loaded
SCSI subsystem initialized
libata version 3.00 loaded.
PCI: Probing PCI hardware
PCI: Probing PCI hardware (bus 00)
pci 0000:00:01.0: reg 10: [io 0xac1c-0xac1f]
pci 0000:00:01.2: reg 10: [mem 0xefff8000-0xefffbfff]
pci 0000:00:09.0: reg 10: [io 0xfc00-0xfcff]
pci 0000:00:09.0: reg 14: [mem 0xeffff000-0xeffff0ff]
pci 0000:00:09.0: supports D1 D2
pci 0000:00:09.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:09.0: PME# disabled
pci 0000:00:0c.0: reg 10: [mem 0xeffe0000-0xeffeffff]
pci 0000:00:0f.0: reg 10: [io 0x6000-0x6007]
pci 0000:00:0f.0: reg 14: [io 0x6100-0x61ff]
pci 0000:00:0f.0: reg 18: [io 0x6200-0x623f]
pci 0000:00:0f.0: reg 1c: [io 0x0000-0x001f]
pci 0000:00:0f.0: reg 20: [io 0x9d00-0x9d7f]
pci 0000:00:0f.0: reg 24: [io 0x9c00-0x9c3f]
pci 0000:00:0f.2: reg 20: [io 0xff00-0xff0f]
pci 0000:00:0f.3: reg 10: [io 0xfe00-0xfe7f]
pci 0000:00:0f.4: reg 10: [mem 0xefffe000-0xefffefff]
pci 0000:00:0f.4: PME# supported from D0 D3hot D3cold
pci 0000:00:0f.4: PME# disabled
pci 0000:00:0f.5: reg 10: [mem 0xefffd000-0xefffdfff]
pci 0000:00:0f.5: PME# supported from D0 D3hot D3cold
pci 0000:00:0f.5: PME# disabled
PCI: pci_cache_line_size set to 32 bytes
reserve RAM buffer: 000000000009e800 - 000000000009ffff
reserve RAM buffer: 000000000ffc0000 - 000000000fffffff
Switching to clocksource tsc
pci 0000:00:0f.0: BAR 3: assigned [io 0x1000-0x101f]
pci 0000:00:0f.0: BAR 3: set to [io 0x1000-0x101f] (PCI address [0x1000-0x101f]
pci_bus 0000:00: resource 0 [io 0x0000-0xffff]
pci_bus 0000:00: resource 1 [mem 0x00000000-0xffffffff]
NET: Registered protocol family 2
IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
TCP established hash table entries: 8192 (order: 4, 65536 bytes)
TCP bind hash table entries: 8192 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP reno registered
UDP hash table entries: 256 (order: 0, 4096 bytes)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
NET: Registered protocol family 1
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
PCI: CLS 32 bytes, default 32
Trying to unpack rootfs image as initramfs...
Freeing initrd memory: 1956k freed
platform rtc_cmos: registered platform RTC device (no PNP device found)
msgmni has been set to 499
alg: No test for stdrng (krng)
io scheduler noop registered
io scheduler cfq registered (default)
Serial: 8250/16550 driver, 2 ports, IRQ sharing enabled
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
brd: module loaded
Uniform Multi-Platform E-IDE driver
amd74xx 0000:00:0f.2: UDMA100 controller
amd74xx 0000:00:0f.2: IDE controller (0x1022:0x209a rev 0x01)
amd74xx 0000:00:0f.2: IDE port disabled
amd74xx 0000:00:0f.2: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xff00-0xff07
Probing IDE interface ide0...
hda: CF CARD 2GB, ATA DISK drive
hda: host max PIO5 wanted PIO255(auto-tune) selected PIO2
hda: MWDMA2 mode selected
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide_generic: please use "probe_mask=0x3f" module parameter for probing all legacy ISA IDE ports
ide-gd driver 1.18
hda: max request size: 128KiB
hda: 3964464 sectors (2029 MB) w/1KiB Cache, CHS=3933/16/63
hda: hda1 hda2
ide-cd driver 5.00
i8042.c: Can't read CTR while initializing i8042.
i8042: probe of i8042 failed with error -5
mice: PS/2 mouse device common for all mice
padlock: VIA PadLock not detected.
padlock: VIA PadLock Hash Engine not detected.
geode-aes: GEODE AES engine enabled.
TCP cubic registered
NET: Registered protocol family 17
Bridge firewalling registered
Using IPI Shortcut mode
Freeing unused kernel memory: 240k freed
Clocksource tsc unstable (delta = 878871247 ns)
Switching to clocksource pit
via-rhine.c:v1.10-LK1.4.3 2007-03-06 Written by Donald Becker
via-rhine 0000:00:09.0: setting latency timer to 64
eth0: VIA Rhine III (Management Adapter) at 0xeffff000, 00:0d:b9:19:98:b4, IRQ 11.
eth0: MII PHY found at address 1, status 0x7869 advertising 05e1 Link 45e1.
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci_hcd 0000:00:0f.5: setting latency timer to 64
ehci_hcd 0000:00:0f.5: EHCI Host Controller
ehci_hcd 0000:00:0f.5: new USB bus registered, assigned bus number 1
ehci_hcd 0000:00:0f.5: irq 5, io mem 0xefffd000
ehci_hcd 0000:00:0f.5: USB 2.0 started, EHCI 1.00
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 4 ports detected
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci_hcd 0000:00:0f.4: setting latency timer to 64
ohci_hcd 0000:00:0f.4: OHCI Host Controller
ohci_hcd 0000:00:0f.4: new USB bus registered, assigned bus number 2
ohci_hcd 0000:00:0f.4: irq 5, io mem 0xefffe000
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 4 ports detected
udev: renamed network interface eth0 to eth1
udevd version 125 started
cs5535_gpio: base=0x6100 mask=0xb003c66 major=254
cfg80211: Calling CRDA to update world regulatory domain
ath5k 0000:00:0c.0: registered as 'phy0'
cfg80211: World regulatory domain updated:
(start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
(2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
ath: EEPROM regdomain: 0x0
ath: EEPROM indicates default country code should be used
ath: doing EEPROM country->regdmn map search
ath: country maps to regdmn code: 0x3a
ath: Country alpha2 being used: US
ath: Regpair used: 0x3a
phy0: Selected rate control algorithm 'minstrel'
ath5k phy0: Atheros AR5414 chip found (MAC: 0xa5, PHY: 0x61)
cfg80211: Calling CRDA for country: US
cs5535audio 0000:00:0f.3: setting latency timer to 64
udev: renamed network interface wlan0 to wlan2
cfg80211: Regulatory domain changed to country: US
(start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
(2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2700 mBm)
(5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 1700 mBm)
(5250000 KHz - 5330000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
(5490000 KHz - 5710000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
(5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 3000 mBm)
EXT2-fs (hda1): warning: mounting unchecked fs, running e2fsck is recommended
EXT2-fs (hda1): error: ext2_lookup: deleted inode referenced: 15608
EXT2-fs (hda1): error: ext2_lookup: deleted inode referenced: 15608
EXT2-fs (hda1): error: ext2_lookup: deleted inode referenced: 15608
EXT2-fs (hda1): error: ext2_lookup: deleted inode referenced: 15608
EXT2-fs (hda1): error: ext2_lookup: deleted inode referenced: 15608
NET: Registered protocol family 10
lo: Disabled Privacy Extensions
eth1: link up, 100Mbps, full-duplex, lpa 0x45E1
eth1: no IPv6 routers present
wlan2: no IPv6 routers present
EXT2-fs (hda1): error: ext2_check_page: bad entry in directory #108731: : unaligned directory entry - offset=0, inode=2940091001, rec_len=24170, name_len=245
EXT2-fs (hda1): error: ext2_readdir: bad page in #108731
EXT2-fs (hda1): error: ext2_check_page: bad entry in directory #108738: : unaligned directory entry - offset=0, inode=944130375, rec_len=24889, name_len=63
EXT2-fs (hda1): error: ext2_readdir: bad page in #108738
EXT2-fs (hda1): error: ext2_check_page: bad entry in directory #108837: : unaligned directory entry - offset=0, inode=1768693795, rec_len=24930, name_len=115
EXT2-fs (hda1): error: ext2_readdir: bad page in #108837
On Wed, Jun 16, 2010 at 04:05:49PM +0200, Dennis Borgmann wrote:
> Hello wireless-list!
> Hello hostapd-list!
>
> I am using ath5k with hostapd-0.6.9 on a debian running kernel 2.6.34
> and I am observing a "ressource temporarily unavailable" - error code 11
> if I pump out multicast-packets quite fast. I wrote a small
> test-program, that handles this test and as soon as I go down to a
> 8ms-pause or below in betweens the packets, the error is thrown quite
> soon after starting the program. Funny thing is, that this error only
> occurs in g-band (2.4 GHz), not in a-band (5GHz).
>
> What could be the problem? Is this due to backoff-times in 2.4 GHz, that
> don't occur on 5 GHz? Or could this be a bug?
My only initial thought is that the 2.5GHz band is usually more
utilized. So there is more likely to be retransmissions, etc.
> Find attached my small piece of code to test and reproduce this effect.
Perhaps you could include actual dmesg output?
John
--
John W. Linville Someday the world will need a hero, and you
[email protected] might be all we have. Be ready.
On Wed, Jun 16, 2010 at 10:05 AM, Dennis Borgmann
<[email protected]> wrote:
> Hello wireless-list!
> Hello hostapd-list!
>
> I am using ath5k with hostapd-0.6.9 on a debian running kernel 2.6.34
> and I am observing a "ressource temporarily unavailable" - error code 11
[...]
> What could be the problem? Is this due to backoff-times in 2.4 GHz, that
> don't occur on 5 GHz? Or could this be a bug?
Does dmesg report any error (e.g. no available txbuf)?
My guess is you have more frequent successful delivery in 5 GHz than in
ISM band so you aren't running out of send buffers somewhere in the stack.
Of course, your program should expect and handle EAGAIN if you are
using MSG_DONTWAIT.
--
Bob Copeland %% http://www.bobcopeland.com