| Message ID | 20201017030701.16134-2-l.wojciechow@partner.samsung.com |
|---|---|
| State | Accepted |
| Delegated to: | David Marchand |
| Headers | show |
| Series |
|
| Related | show |
| Context | Check | Description |
|---|---|---|
| ci/checkpatch | success | coding style OK |
<snip> > > rte_distributor_return_pkt function which is run on worker cores must wait > for distributor core to clear handshake on retptr64 before using those > buffers. While the handshake is set distributor core controls buffers and any > operations on worker side might overwrite buffers which are unread yet. > Same situation appears in the legacy single distributor. Function > rte_distributor_return_pkt_single shouldn't modify the bufptr64 until > handshake on it is cleared by distributor lcore. > > Fixes: 775003ad2f96 ("distributor: add new burst-capable library") > Cc: david.hunt@intel.com > Cc: stable@dpdk.org > > Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com> > Acked-by: David Hunt <david.hunt@intel.com> Looks good. Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> > --- > lib/librte_distributor/rte_distributor.c | 12 ++++++++++++ > lib/librte_distributor/rte_distributor_single.c | 4 ++++ > 2 files changed, 16 insertions(+) > > diff --git a/lib/librte_distributor/rte_distributor.c > b/lib/librte_distributor/rte_distributor.c > index 1c047f065..c6b19a388 100644 > --- a/lib/librte_distributor/rte_distributor.c > +++ b/lib/librte_distributor/rte_distributor.c > @@ -169,6 +169,18 @@ rte_distributor_return_pkt(struct rte_distributor *d, > return -EINVAL; > } > > + /* Spin while handshake bits are set (scheduler clears it). > + * Sync with worker on GET_BUF flag. > + */ > + while (unlikely(__atomic_load_n(&(buf->retptr64[0]), > __ATOMIC_RELAXED) > + & RTE_DISTRIB_GET_BUF)) { > + rte_pause(); > + uint64_t t = rte_rdtsc()+100; > + > + while (rte_rdtsc() < t) > + rte_pause(); > + } > + > /* Sync with distributor to acquire retptrs */ > __atomic_thread_fence(__ATOMIC_ACQUIRE); > for (i = 0; i < RTE_DIST_BURST_SIZE; i++) diff --git > a/lib/librte_distributor/rte_distributor_single.c > b/lib/librte_distributor/rte_distributor_single.c > index abaf7730c..f4725b1d0 100644 > --- a/lib/librte_distributor/rte_distributor_single.c > +++ b/lib/librte_distributor/rte_distributor_single.c > @@ -74,6 +74,10 @@ rte_distributor_return_pkt_single(struct > rte_distributor_single *d, > union rte_distributor_buffer_single *buf = &d->bufs[worker_id]; > uint64_t req = (((int64_t)(uintptr_t)oldpkt) << > RTE_DISTRIB_FLAG_BITS) > | RTE_DISTRIB_RETURN_BUF; > + while (unlikely(__atomic_load_n(&buf->bufptr64, > __ATOMIC_RELAXED) > + & RTE_DISTRIB_FLAGS_MASK)) > + rte_pause(); > + > /* Sync with distributor on RETURN_BUF flag. */ > __atomic_store_n(&(buf->bufptr64), req, __ATOMIC_RELEASE); > return 0; > -- > 2.17.1
diff --git a/lib/librte_distributor/rte_distributor.c b/lib/librte_distributor/rte_distributor.c index 1c047f065..c6b19a388 100644 --- a/lib/librte_distributor/rte_distributor.c +++ b/lib/librte_distributor/rte_distributor.c @@ -169,6 +169,18 @@ rte_distributor_return_pkt(struct rte_distributor *d, return -EINVAL; } + /* Spin while handshake bits are set (scheduler clears it). + * Sync with worker on GET_BUF flag. + */ + while (unlikely(__atomic_load_n(&(buf->retptr64[0]), __ATOMIC_RELAXED) + & RTE_DISTRIB_GET_BUF)) { + rte_pause(); + uint64_t t = rte_rdtsc()+100; + + while (rte_rdtsc() < t) + rte_pause(); + } + /* Sync with distributor to acquire retptrs */ __atomic_thread_fence(__ATOMIC_ACQUIRE); for (i = 0; i < RTE_DIST_BURST_SIZE; i++) diff --git a/lib/librte_distributor/rte_distributor_single.c b/lib/librte_distributor/rte_distributor_single.c index abaf7730c..f4725b1d0 100644 --- a/lib/librte_distributor/rte_distributor_single.c +++ b/lib/librte_distributor/rte_distributor_single.c @@ -74,6 +74,10 @@ rte_distributor_return_pkt_single(struct rte_distributor_single *d, union rte_distributor_buffer_single *buf = &d->bufs[worker_id]; uint64_t req = (((int64_t)(uintptr_t)oldpkt) << RTE_DISTRIB_FLAG_BITS) | RTE_DISTRIB_RETURN_BUF; + while (unlikely(__atomic_load_n(&buf->bufptr64, __ATOMIC_RELAXED) + & RTE_DISTRIB_FLAGS_MASK)) + rte_pause(); + /* Sync with distributor on RETURN_BUF flag. */ __atomic_store_n(&(buf->bufptr64), req, __ATOMIC_RELEASE); return 0;
rte_distributor_return_pkt function which is run on worker cores must wait for distributor core to clear handshake on retptr64 before using those buffers. While the handshake is set distributor core controls buffers and any operations on worker side might overwrite buffers which are unread yet. Same situation appears in the legacy single distributor. Function rte_distributor_return_pkt_single shouldn't modify the bufptr64 until handshake on it is cleared by distributor lcore. Fixes: 775003ad2f96 ("distributor: add new burst-capable library") Cc: david.hunt@intel.com Cc: stable@dpdk.org Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com> Acked-by: David Hunt <david.hunt@intel.com> --- lib/librte_distributor/rte_distributor.c | 12 ++++++++++++ lib/librte_distributor/rte_distributor_single.c | 4 ++++ 2 files changed, 16 insertions(+)