From: Jakub Kicinski Date: Fri, 15 Apr 2022 21:02:09 +0000 (-0700) Subject: Merge branch 'ibmvnic-use-a-set-of-ltbs-per-pool' X-Git-Tag: for-5.19/block-exec-2022-06-02~49^2~305 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a992005cc88bdb6628110b97afe8651baa87f1e3;p=linux-2.6-block.git Merge branch 'ibmvnic-use-a-set-of-ltbs-per-pool' Sukadev Bhattiprolu says: ==================== ibmvnic: Use a set of LTBs per pool ibmvnic uses a single large long term buffer (LTB) per rx or tx pool (queue). This has two limitations. First, if we need to free/allocate an LTB (eg during a reset), under low memory conditions, the allocation can fail. Second, the kernel limits the size of single LTB (DMA buffer) to 16MB (based on MAX_ORDER). With jumbo frames (mtu = 9000) we can only have about 1763 buffers per LTB (16MB / 9588 bytes per frame) even though the max supported buffers is 4096. (The 9588 instead of 9088 comes from IBMVNIC_BUFFER_HLEN.) To overcome these limitations, allow creating a set of LTBs per queue. ==================== Link: https://lore.kernel.org/r/20220413171026.1264294-1-drt@linux.ibm.com Signed-off-by: Jakub Kicinski --- a992005cc88bdb6628110b97afe8651baa87f1e3