sivakumar.subramani@wipro.com
2006-Nov-07 05:16 UTC
Regarding Jumbo frame implementation in bge
Hi, In bge driver, we have BGE_JUMBO_FRAMELEN defined to 9018. if_bgereg.h:#define BGE_JUMBO_FRAMELEN 9018 This macro is used to allocate the memory for jumbo buffer. If I have a MTU size of 2000, still bge will allocate the jumbo buffer of size BGE_JUMBO_FRAMELEN. Instead can we make the size to be depend on the MTU. I mean instead of using BGE_JUMBO_FRAMELEN macro we can use MTU + IP header + CRC for Jumbo buffer size. Any reason for allocating a hard coded 9018 size all Jumbo MTU frame (whether it is 9000 / 2000)? Thanks, ~Siva The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com
sivakumar.subramani@wipro.com wrote:> Hi, > > In bge driver, we have BGE_JUMBO_FRAMELEN defined to 9018. > if_bgereg.h:#define BGE_JUMBO_FRAMELEN 9018 > > This macro is used to allocate the memory for jumbo buffer. If I have > a MTU size of 2000, still bge will allocate the jumbo buffer of size > BGE_JUMBO_FRAMELEN. Instead can we make the size to be depend on the > MTU. I mean instead of using BGE_JUMBO_FRAMELEN macro we can use MTU > + IP header + CRC for Jumbo buffer size. > > Any reason for allocating a hard coded 9018 size all Jumbo MTU frame > (whether it is 9000 / 2000)? > > Thanks, ~Siva >Sivakumar: Allocations are done via the zone managers.. and thus setup at kernel boot. A value like the MTU is set dynamically... So doing something like this would be questionable IMO.. I am sure it could be done.. but I don't see the value. In theory you have a waste for just a short time.. before its m_free'd R -- Randall Stewart NSSTG - Cisco Systems Inc. 803-345-0369 <or> 803-317-4952 (cell)