This patch belongs to the iquery scheduler patch set. Without the rest of the code, it's impossible to tell if this change is needed or correct.
-Petri > -----Original Message----- > From: lng-odp [mailto:lng-odp-boun...@lists.linaro.org] On Behalf Of Yi He > Sent: Thursday, December 08, 2016 8:33 AM > To: lng-odp@lists.linaro.org; bill.fischo...@linaro.org; Elo, Matias > (Nokia - FI/Espoo) <matias....@nokia-bell-labs.com> > Subject: [lng-odp] [API-NEXT PATCH] linux-gen: scheduler: solve ordered > context inversion > > For ordered queue, a thread consumes events (dequeue) and > acquires its unique sequential context in two steps, non > atomic and preemptable. > > This leads to potential ordered context inversion in case > the thread consumes prior events acquired subsequent context, > while the thread consumes subsequent events but acquired > prior context. > > This patch insert the ordered context acquisition into > event dequeue operation to make these two steps atomic. > > Signed-off-by: Yi He <yi...@linaro.org> > --- > When I'm rebase iquery scheduler onto Matias' new ordered > queue impl I found this potential ordered context inversion > issue, it didnot happen to the default scheduler but happens > to the iquery scheduler, so after patchset will rely on this > patch. please help review thanks. > > platform/linux-generic/include/odp_schedule_if.h | 3 +++ > platform/linux-generic/odp_queue.c | 3 +++ > platform/linux-generic/odp_schedule.c | 7 ++++++- > platform/linux-generic/odp_schedule_sp.c | 7 ++++++- > 4 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/platform/linux-generic/include/odp_schedule_if.h > b/platform/linux-generic/include/odp_schedule_if.h > index 6c2b050..c0aee42 100644 > --- a/platform/linux-generic/include/odp_schedule_if.h > +++ b/platform/linux-generic/include/odp_schedule_if.h > @@ -12,6 +12,7 @@ extern "C" { > #endif > > #include <odp/api/queue.h> > +#include <odp_queue_internal.h> > #include <odp/api/schedule.h> > > typedef void (*schedule_pktio_start_fn_t)(int pktio_index, int > num_in_queue, > @@ -33,6 +34,7 @@ typedef int (*schedule_term_local_fn_t)(void); > typedef void (*schedule_order_lock_fn_t)(void); > typedef void (*schedule_order_unlock_fn_t)(void); > typedef unsigned (*schedule_max_ordered_locks_fn_t)(void); > +typedef void (*schedule_save_context_fn_t)(queue_entry_t *queue); > > typedef struct schedule_fn_t { > schedule_pktio_start_fn_t pktio_start; > @@ -50,6 +52,7 @@ typedef struct schedule_fn_t { > schedule_order_lock_fn_t order_lock; > schedule_order_unlock_fn_t order_unlock; > schedule_max_ordered_locks_fn_t max_ordered_locks; > + schedule_save_context_fn_t save_context; > } schedule_fn_t; > > /* Interface towards the scheduler */ > diff --git a/platform/linux-generic/odp_queue.c b/platform/linux- > generic/odp_queue.c > index d9cb9f3..3b6a68b 100644 > --- a/platform/linux-generic/odp_queue.c > +++ b/platform/linux-generic/odp_queue.c > @@ -568,6 +568,9 @@ static inline int deq_multi(queue_entry_t *queue, > odp_buffer_hdr_t *buf_hdr[], > if (hdr == NULL) > queue->s.tail = NULL; > > + if (queue->s.type == ODP_QUEUE_TYPE_SCHED) > + sched_fn->save_context(queue); > + > UNLOCK(&queue->s.lock); > > return i; > diff --git a/platform/linux-generic/odp_schedule.c b/platform/linux- > generic/odp_schedule.c > index 645630a..264c58f 100644 > --- a/platform/linux-generic/odp_schedule.c > +++ b/platform/linux-generic/odp_schedule.c > @@ -1205,6 +1205,10 @@ static int schedule_num_grps(void) > return NUM_SCHED_GRPS; > } > > +static void schedule_save_context(queue_entry_t *queue ODP_UNUSED) > +{ > +} > + > /* Fill in scheduler interface */ > const schedule_fn_t schedule_default_fn = { > .pktio_start = schedule_pktio_start, > @@ -1221,7 +1225,8 @@ const schedule_fn_t schedule_default_fn = { > .term_local = schedule_term_local, > .order_lock = order_lock, > .order_unlock = order_unlock, > - .max_ordered_locks = schedule_max_ordered_locks > + .max_ordered_locks = schedule_max_ordered_locks, > + .save_context = schedule_save_context > }; > > /* Fill in scheduler API calls */ > diff --git a/platform/linux-generic/odp_schedule_sp.c b/platform/linux- > generic/odp_schedule_sp.c > index 76d1357..8481f29 100644 > --- a/platform/linux-generic/odp_schedule_sp.c > +++ b/platform/linux-generic/odp_schedule_sp.c > @@ -676,6 +676,10 @@ static void order_unlock(void) > { > } > > +static void save_context(queue_entry_t *queue ODP_UNUSED) > +{ > +} > + > /* Fill in scheduler interface */ > const schedule_fn_t schedule_sp_fn = { > .pktio_start = pktio_start, > @@ -692,7 +696,8 @@ const schedule_fn_t schedule_sp_fn = { > .term_local = term_local, > .order_lock = order_lock, > .order_unlock = order_unlock, > - .max_ordered_locks = max_ordered_locks > + .max_ordered_locks = max_ordered_locks, > + .save_context = save_context > }; > > /* Fill in scheduler API calls */ > -- > 2.7.4
