On Wed, Mar 4, 2020 at 9:33 PM Jerin Jacob <jerinjac...@gmail.com> wrote: > > On Wed, Mar 4, 2020 at 6:48 PM Tonghao Zhang <xiangxia.m....@gmail.com> wrote: > > > > On Mon, Mar 2, 2020 at 9:45 PM Jerin Jacob <jerinjac...@gmail.com> wrote: > > > > > > On Mon, Mar 2, 2020 at 7:27 AM <xiangxia.m....@gmail.com> wrote: > > > > > > > > From: Tonghao Zhang <xiangxia.m....@gmail.com> > > > > > > > > The order of mempool initiation affects mempool index in the > > > > rte_mempool_ops_table. For example, when building APPs with: > > > > > > > > $ gcc -lrte_mempool_bucket -lrte_mempool_ring ... > > > > > > > > The "bucket" mempool will be registered firstly, and its index > > > > in table is 0 while the index of "ring" mempool is 1. DPDK > > > > uses the mk/rte.app.mk to build APPs, and others, for example, > > > > Open vSwitch, use the libdpdk.a or libdpdk.so to build it. > > > > The mempool lib linked in dpdk and Open vSwitch is different. > > > > > > > > The mempool can be used between primary and secondary process, > > > > such as dpdk-pdump and pdump-pmd/Open vSwitch(pdump enabled). > > > > There will be a crash because dpdk-pdump creates the "ring_mp_mc" > > > > ring which index in table is 0, but the index of "bucket" ring > > > > is 0 in Open vSwitch. If Open vSwitch use the index 0 to get > > > > mempool ops and malloc memory from mempool. The crash will occur: > > > > > > > > bucket_dequeue (access null and crash) > > > > rte_mempool_get_ops (should get "ring_mp_mc", > > > > but get "bucket" mempool) > > > > rte_mempool_ops_dequeue_bulk > > > > ... > > > > rte_pktmbuf_alloc > > > > rte_pktmbuf_copy > > > > pdump_copy > > > > pdump_rx > > > > rte_eth_rx_burst > > > > > > > > To avoid the crash, there are some solution: > > > > * constructor priority: Different mempool uses different > > > > priority in RTE_INIT, but it's not easy to maintain. > > > > > > > > * change mk/rte.app.mk: Change the order in mk/rte.app.mk to > > > > be same as libdpdk.a/libdpdk.so, but when adding a new mempool > > > > driver in future, we must make sure the order. > > > > > > > > * register mempool orderly: Sort the mempool when registering, > > > > so the lib linked will not affect the index in mempool table. > > > > > > > > Signed-off-by: Tonghao Zhang <xiangxia.m....@gmail.com> > > > > --- > > > > lib/librte_mempool/rte_mempool_ops.c | 18 ++++++++++++++++-- > > > > 1 file changed, 16 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/lib/librte_mempool/rte_mempool_ops.c > > > > b/lib/librte_mempool/rte_mempool_ops.c > > > > index 22c5251..06dfe16 100644 > > > > --- a/lib/librte_mempool/rte_mempool_ops.c > > > > +++ b/lib/librte_mempool/rte_mempool_ops.c > > > > @@ -22,7 +22,7 @@ struct rte_mempool_ops_table rte_mempool_ops_table = { > > > > rte_mempool_register_ops(const struct rte_mempool_ops *h) > > > > { > > > > struct rte_mempool_ops *ops; > > > > - int16_t ops_index; > > > > + unsigned ops_index, i; > > > > > > > > rte_spinlock_lock(&rte_mempool_ops_table.sl); > > > > > > > > @@ -50,7 +50,19 @@ struct rte_mempool_ops_table rte_mempool_ops_table = > > > > { > > > > return -EEXIST; > > > > } > > > > > > > > - ops_index = rte_mempool_ops_table.num_ops++; > > > > + /* sort the rte_mempool_ops by name. the order of the mempool > > > > + * lib initiation will not affect rte_mempool_ops index. */ > > > > > > +1 for the fix. > > > For the implementation, why not use qsort_r() for sorting? > > The implementation is easy, and the number of mempool driver is not too > > large. > > But we can use the qsort_r to implement it. > > Since it is in a slow path, IMO, better to use standard sort functions > for better readability. Agree, can you help me review the patch:
diff --git a/lib/librte_mempool/rte_mempool_ops.c b/lib/librte_mempool/rte_mempool_ops.c index 22c5251..1acee58 100644 --- a/lib/librte_mempool/rte_mempool_ops.c +++ b/lib/librte_mempool/rte_mempool_ops.c @@ -17,6 +17,15 @@ struct rte_mempool_ops_table rte_mempool_ops_table = { .num_ops = 0 }; +static int +compare_mempool_ops(const void *a, const void *b) +{ + const struct rte_mempool_ops *m_a = a; + const struct rte_mempool_ops *m_b = b; + + return strcmp(m_a->name, m_b->name); +} + /* add a new ops struct in rte_mempool_ops_table, return its index. */ int rte_mempool_register_ops(const struct rte_mempool_ops *h) @@ -63,6 +72,9 @@ struct rte_mempool_ops_table rte_mempool_ops_table = { ops->get_info = h->get_info; ops->dequeue_contig_blocks = h->dequeue_contig_blocks; + qsort(rte_mempool_ops_table.ops, rte_mempool_ops_table.num_ops, + sizeof(rte_mempool_ops_table.ops[0]), compare_mempool_ops); + rte_spinlock_unlock(&rte_mempool_ops_table.sl); return ops_index; > > > > > > > > + ops_index = rte_mempool_ops_table.num_ops; > > > > + for (i = 0; i < rte_mempool_ops_table.num_ops; i++) { > > > > + if (strcmp(h->name, rte_mempool_ops_table.ops[i].name) > > > > < 0) { > > > > + do { > > > > + rte_mempool_ops_table.ops[ops_index] = > > > > + > > > > rte_mempool_ops_table.ops[ops_index -1]; > > > > + } while (--ops_index > i); > > > > + break; > > > > + } > > > > + } > > > > + > > > > ops = &rte_mempool_ops_table.ops[ops_index]; > > > > strlcpy(ops->name, h->name, sizeof(ops->name)); > > > > ops->alloc = h->alloc; > > > > @@ -63,6 +75,8 @@ struct rte_mempool_ops_table rte_mempool_ops_table = { > > > > ops->get_info = h->get_info; > > > > ops->dequeue_contig_blocks = h->dequeue_contig_blocks; > > > > > > > > + rte_mempool_ops_table.num_ops++; > > > > + > > > > rte_spinlock_unlock(&rte_mempool_ops_table.sl); > > > > > > > > return ops_index; > > > > -- > > > > 1.8.3.1 > > > > > > > > > > > > -- > > Thanks, > > Tonghao -- Thanks, Tonghao