Hello, I tested all day both before and after patching. I could not understand that it is a memory leak or not. Maybe it needs optimization. You lead, I follow. 1-) You are right, alloc_q is never bigger than 1024. But it always allocates 32 units then more than 1024 are being freed. Maybe it takes time, I don't know. 2-) I tested tx_rs_thresh via ping. After 210 sec , allocated memories are back to mempool (most of them). (driver virtio and eth-devices are binded via igb_uio) . It really takes time. So it is better to increase the size of the mempool. (https://doc.dpdk.org/guides/prog_guide/poll_mode_drv.html) 3-) try to list mempool state in randomly Test -1 -) (old code) ICMP testing. The whole mempool size is about 10350. So after FIFO reaches max-size -1024, %10 of the size of the mempool is in use. But little by little memory is waiting in use and doesn't go back to the pool. I could not find the reason. MBUF_POOL 448 9,951 4.31% [|....................] MBUF_POOL 1,947 8,452 18.72% [||||.................] MBUF_POOL 1,803 8,596 17.34% [||||.................] MBUF_POOL 1,941 8,458 18.67% [||||.................] MBUF_POOL 1,900 8,499 18.27% [||||.................] MBUF_POOL 1,999 8,400 19.22% [||||.................] MBUF_POOL 1,724 8,675 16.58% [||||.................] MBUF_POOL 1,811 8,588 17.42% [||||.................] MBUF_POOL 1,978 8,421 19.02% [||||.................] MBUF_POOL 2,008 8,391 19.31% [||||.................] MBUF_POOL 1,854 8,545 17.83% [||||.................] MBUF_POOL 1,922 8,477 18.48% [||||.................] MBUF_POOL 1,892 8,507 18.19% [||||.................] MBUF_POOL 1,957 8,442 18.82% [||||.................] Test-2 -) (old code) run iperf3 udp testing that from Kernel to eth device. Waited to see what happens in 4 min. memory doesn't go back to the mempool. little by little, memory usage increases. MBUF_POOL 512 9,887 4.92% [|....................] MBUF_POOL 1,411 8,988 13.57% [|||..................] MBUF_POOL 1,390 9,009 13.37% [|||..................] MBUF_POOL 1,558 8,841 14.98% [|||..................] MBUF_POOL 1,453 8,946 13.97% [|||..................] MBUF_POOL 1,525 8,874 14.66% [|||..................] MBUF_POOL 1,592 8,807 15.31% [||||.................] MBUF_POOL 1,639 8,760 15.76% [||||.................] MBUF_POOL 1,624 8,775 15.62% [||||.................] MBUF_POOL 1,618 8,781 15.56% [||||.................] MBUF_POOL 1,708 8,691 16.42% [||||.................] iperf is STOPPED to tx_fresh for 4 min MBUF_POOL 1,709 8,690 16.43% [||||.................] iperf is STOPPED to tx_fresh for 4 min MBUF_POOL 1,709 8,690 16.43% [||||.................] MBUF_POOL 1,683 8,716 16.18% [||||.................] MBUF_POOL 1,563 8,836 15.03% [||||.................] MBUF_POOL 1,726 8,673 16.60% [||||.................] MBUF_POOL 1,589 8,810 15.28% [||||.................] MBUF_POOL 1,556 8,843 14.96% [|||..................] MBUF_POOL 1,610 8,789 15.48% [||||.................] MBUF_POOL 1,616 8,783 15.54% [||||.................] MBUF_POOL 1,709 8,690 16.43% [||||.................] MBUF_POOL 1,740 8,659 16.73% [||||.................] MBUF_POOL 1,546 8,853 14.87% [|||..................] MBUF_POOL 1,710 8,689 16.44% [||||.................] MBUF_POOL 1,787 8,612 17.18% [||||.................] MBUF_POOL 1,579 8,820 15.18% [||||.................] MBUF_POOL 1,780 8,619 17.12% [||||.................] MBUF_POOL 1,679 8,720 16.15% [||||.................] MBUF_POOL 1,604 8,795 15.42% [||||.................] MBUF_POOL 1,761 8,638 16.93% [||||.................] MBUF_POOL 1,773 8,626 17.05% [||||.................] Test-3 -) (after patching) run iperf3 udp testing that from Kernel to eth device. looks stable. After patching , MBUF_POOL 76 10,323 0.73% [|....................] MBUF_POOL 193 10,206 1.86% [|....................] MBUF_POOL 96 10,303 0.92% [|....................] MBUF_POOL 269 10,130 2.59% [|....................] MBUF_POOL 102 10,297 0.98% [|....................] MBUF_POOL 235 10,164 2.26% [|....................] MBUF_POOL 87 10,312 0.84% [|....................] MBUF_POOL 293 10,106 2.82% [|....................] MBUF_POOL 99 10,300 0.95% [|....................] MBUF_POOL 296 10,103 2.85% [|....................] MBUF_POOL 90 10,309 0.87% [|....................] MBUF_POOL 299 10,100 2.88% [|....................] MBUF_POOL 86 10,313 0.83% [|....................] MBUF_POOL 262 10,137 2.52% [|....................] MBUF_POOL 81 10,318 0.78% [|....................] MBUF_POOL 81 10,318 0.78% [|....................] MBUF_POOL 87 10,312 0.84% [|....................] MBUF_POOL 252 10,147 2.42% [|....................] MBUF_POOL 97 10,302 0.93% [|....................] iperf is STOPPED to tx_fresh for 4 min MBUF_POOL 296 10,103 2.85% [|....................] MBUF_POOL 95 10,304 0.91% [|....................] MBUF_POOL 269 10,130 2.59% [|....................] MBUF_POOL 302 10,097 2.90% [|....................] MBUF_POOL 88 10,311 0.85% [|....................] MBUF_POOL 305 10,094 2.93% [|....................] MBUF_POOL 88 10,311 0.85% [|....................] MBUF_POOL 290 10,109 2.79% [|....................] MBUF_POOL 84 10,315 0.81% [|....................] MBUF_POOL 85 10,314 0.82% [|....................] MBUF_POOL 291 10,108 2.80% [|....................] MBUF_POOL 303 10,096 2.91% [|....................] MBUF_POOL 92 10,307 0.88% [|....................] Best regards. Ferruh Yigit , 18 May 2023 Per, 17:56 tarihinde şunu yazdı: > On 5/18/2023 9:14 AM, Yasin CANER wrote: > > Hello Ferruh, > > > > Thanks for your kind response. Also thanks to Stephen. > > > > Even if 1 packet is consumed from the kernel , each time rx_kni > > allocates another 32 units. After a while all mempool is used in alloc_q > > from kni. there is not any room for it. > > > > What you described continues until 'alloc_q' is full, by default fifo > length is 1024 (KNI_FIFO_COUNT_MAX), do you allocate less mbuf in your > mempool? > > You can consider either increasing mempool size, or decreasing 'alloc_q' > fifo length, but reducing fifo size may cause performance issues so you > need to evaluate that option. > > > Do you think my mistake is using one and common mempool usage both kni > > and eth? > > > > Using same mempool for both is fine. > > > If it needs a separate mempool , i'd like to note in docs. > > > > Best regards. > > > > Ferruh Yigit >, 17 > > May 2023 Çar, 20:53 tarihinde şunu yazdı: > > > > On 5/9/2023 12:13 PM, Yasin CANER wrote: > > > Hello, > > > > > > I draw a flow via asciiflow to explain myself better. Problem is > after > > > transmitting packets(mbufs) , it never puts in the kni->free_q to > back > > > to the original pool. Each cycle, it allocates another 32 units > that > > > cause leaks. Or I am missing something. > > > > > > I already tried the rte_eth_tx_done_cleanup() function but it > > didn't fix > > > anything. > > > > > > I am working on a patch to fix this issue but I am not sure if > there > > > is another way. > > > > > > Best regards. > > > > > > https://pastebin.ubuntu.com/p/s4h5psqtgZ/ > > > > > > > > > > > > > > > > unsigned > > > rte_kni_rx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, > > unsigned > > > int num) > > > { > > > unsigned int ret = kni_fifo_get(kni->tx_q, (void **)mbufs, num); > > > > > > /* If buffers removed, allocate mbufs and then put them into > > alloc_q */ > > > /* Question, how to test buffers is removed or not?*/ > > > if (ret) > > > kni_allocate_mbufs(kni); > > > > > > return ret; > > > } > > > > > > > Selam Yasin, > > > > > > You can expect 'kni->alloc_q' fifo to be full, this is not a memory > > leak. > > > > As you pointed out, number of mbufs consumed by kernel from 'alloc_q' > > and number of mbufs added to 'alloc_q' is not equal and this is > > expected. > > > > Target here is to prevent buffer underflow from kernel perspective, > so > > it will always have available mbufs for new packets. > > That is why new mbufs are added to 'alloc_q' at worst same or > sometimes > > higher rate than it is consumed. > > > > You should calculate your mbuf requirement with the assumption that > > 'kni->alloc_q' will be full of mbufs. > > > > > > 'kni->alloc_q' is freed when kni is removed. > > Since 'alloc_q' holds physical address of the mbufs, it is a little > > challenging to free them in the userspace, that is why first kernel > > tries to move mbufs to 'kni->free_q' fifo, please check > > 'kni_net_release_fifo_phy()' for it. > > > > If all moved to 'free_q' fifo, nothing left to in 'alloc_q', but if > not, > > userspace frees 'alloc_q' in 'rte_kni_release()', with following > call: > > `kni_free_fifo_phy(kni->pktmbuf_pool, kni->alloc_q);` > > > > > > I can see you have submitted fixes for this issue, although as I > > explained above I don't think a defect exist, I will review them > > today/tomorrow. > > > > Regards, > > Ferruh > > > > > > > Stephen Hemminger > > > > > >>, 8 May 2023 Pzt, 19:18 > tarihinde > > > şunu yazdı: > > > > > > On Mon, 8 May 2023 09:01:41 +0300 > > > Yasin CANER > > >> > > > wrote: > > > > > > > Hello Stephen, > > > > > > > > Thank you for response, it helps me a lot. I understand > problem > > > better. > > > > > > > > After reading mbuf library ( > > > > https://doc.dpdk.org/guides/prog_guide/mempool_lib.html > > > > > > >) i > > > realized that > > > > 31 units allocation memory slot doesn't return to pool! > > > > > > If receive burst returns 1 mbuf, the other 31 pointers in the > > array > > > are not valid. They do not point to mbufs. > > > > > > > 1 unit mbuf can be freed via rte_pktmbuf_free so it can back > > to pool. > > > > > > > > Main problem is that allocation doesn't return to original > pool, > > > act as > > > > used. So, after following rte_pktmbuf_free > > > > > > > > > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a1215458932900b7cd5192326fa4a6902 > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a1215458932900b7cd5192326fa4a6902> > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a1215458932900b7cd5192326fa4a6902 > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a1215458932900b7cd5192326fa4a6902 > >>> > > > > function, > > > > i realized that there is 2 function to helps to mbufs back > > to pool. > > > > > > > > These are rte_mbuf_raw_free > > > > > > > > > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a9f188d53834978aca01ea101576d7432 > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a9f188d53834978aca01ea101576d7432> > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a9f188d53834978aca01ea101576d7432 > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a9f188d53834978aca01ea101576d7432 > >>> > > > > and rte_pktmbuf_free_seg > > > > > > > > > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a006ee80357a78fbb9ada2b0432f82f37 > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a006ee80357a78fbb9ada2b0432f82f37> > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a006ee80357a78fbb9ada2b0432f82f37 > < > http://doc.dpdk.org/api/rte__mbuf_8h.html#a006ee80357a78fbb9ada2b0432f82f37 > >>>. > > > > I will focus on them. > > > > > > > > If there is another suggestion, I will be very pleased. > > > > > > > > Best regards. > > > > > > > > Yasin CANER > > > > Ulak > > > > > > >