Hi! On 18:37 Tue 21 Apr , Devesh Sharma wrote: > Hello michi, Sorry for late reply. comments are inline: ... > > Is there any packet loss on the link? What does "ping -f" and > packet loss is very less......after data transfer in TBits I observer > on 5 tx packet drops > > "ping -f -s 4096" say? How much does the latency increase if you send > > bigger packets? Is there a "magic value" which causes a "sudden increase" > > (e.g. 4051 is much slower than 4050)? > Yes there is a magic number for packet size of 4040 bytes in ping -s > 4040 gives proper results > but of ping -s 4041 every alternate packet get delayed upto 1000 ms. This is interesting: Ethernet header is 14 byte + 4 byte crc32 (you said, you are using something else, do you know the header/trailer size?) IP header is 20 byte UDP header is 8 byte (what prococol are you using?) --- 54 bytes 4040+54 = 4094 This is very close to the 4096 page size most machines have. But 1000 ms for a 8KB continuous memory allocation on a machine with 64GB RAM sounds pretty extreme. Maybe oprofile has has clues or there was a regression and older kernels run faster? -Michi -- programing a layer 3+4 network protocol for mesh networks see http://michaelblizek.twilightparadox.com -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
