Regarding connector netlink running out of buffer space.
Hi, I am trying to benchmark connector netlink and am passing a file and sending the same to listening userspace app's using connectors i.e. cat filename > /dev/myconnector and an app listening. When I do this I always run into ENOBUFS or "No buffer space available" for files greater than 2MB. Now how should I fix this? a) Increase the socket buffers? My rmem_max is 131071 and rmem_default is 126976 b) Should I check for the seq and ack and resend the packets? If yes how much packets should I not discard to do a resend? Are there any other ways? Also I am not sure why local loop would cause enobufs? I am running this on a quad core with 3G of RAM. Thanks.
-----Original Message----- From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies- bounces@kernelnewbies.org] On Behalf Of mindentropy Sent: Friday, July 29, 2011 1:35 PM To: kernelnewbies@kernelnewbies.org Subject: Regarding connector netlink running out of buffer space.
Hi, I am trying to benchmark connector netlink and am passing a file and sending the same to listening userspace app's using connectors i.e. cat filename > /dev/myconnector and an app listening. When I do this I always run into ENOBUFS or "No buffer space available" for files greater than 2MB. Now how should I fix this? a) Increase the socket buffers? My rmem_max is 131071 and rmem_default is 126976 b) Should I check for the seq and ack and resend the packets? If yes how much packets should I not discard to do a resend?
Are there any other ways? Also I am not sure why local loop would cause enobufs? I am running this on a quad core with 3G of RAM.
Thanks.
Just guessing here, but it's possible the kernel is attempting to kmalloc() a single buffer for the whole file and with the file at 2MB there's no slab/slob/slub with buffers that big. You might need to write to /dev/myconnector in smaller chunks. Again, just a guess.
On Saturday 30 Jul 2011 2:23:58 AM Jeff Haran wrote:
-----Original Message----- From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies- bounces@kernelnewbies.org] On Behalf Of mindentropy Sent: Friday, July 29, 2011 1:35 PM To: kernelnewbies@kernelnewbies.org Subject: Regarding connector netlink running out of buffer space.
Hi,
I am trying to benchmark connector netlink and am passing a file and
sending the same to listening userspace app's using connectors i.e. cat filename > /dev/myconnector and an app listening. When I do this I always run into
ENOBUFS or "No buffer space available" for files greater than 2MB. Now how should I fix this? a) Increase the socket buffers? My rmem_max is 131071 and rmem_default is 126976 b) Should I check for the seq and ack and resend the packets? If yes how much packets should I not discard to do a resend?
Are there any other ways? Also I am not sure why local loop would cause enobufs? I am running this on a quad core with 3G of RAM.
Thanks.
Just guessing here, but it's possible the kernel is attempting to kmalloc() a single buffer for the whole file and with the file at 2MB there's no slab/slob/slub with buffers that big. You might need to write to /dev/myconnector in smaller chunks.
Again, just a guess.
My device write file operation as of now accepts 1024 byte chunks. So my payload size is just 1024 bytes. For simple testing I tried with just 5 bytes. This too fails.
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mindentropy