search for: llist_for_each_saf

Displaying 5 results from an estimated 5 matches for "llist_for_each_saf".

Did you mean: llist_for_each_safe
2023 May 23
4
[PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
...ry_safe(work, work_next, node, node) { clear_bit(VHOST_WORK_QUEUED, &work->flags); I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, vhost_work_queue() can add this work again and change work->node->next. That is why we use _safe, but we need to ensure that llist_for_each_safe() completes LOAD(work->node->next) before VHOST_WORK_QUEUED is cleared. So it seems that smp_wmb() can't help and should be removed, instead we need llist_for_each_entry_safe(...) { smp_mb__before_atomic(); clear_bit(VHOST_WORK_QUEUED, &work->flags); Also, if the work-&...
2023 May 31
1
[PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
...t; > > > > > > >I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, > > > >vhost_work_queue() can add this work again and change work->node->next. > > > > > > > >That is why we use _safe, but we need to ensure that llist_for_each_safe() > > > >completes LOAD(work->node->next) before VHOST_WORK_QUEUED is cleared. > > > > > > This should be fine since store is not speculated, so work->node->next needs > > > to be loaded before VHOST_WORK_QUEUED is cleared to meet the loop conditi...
2023 May 22
1
[PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
On 05/22, Mike Christie wrote: > > On 5/22/23 7:30 AM, Oleg Nesterov wrote: > >> + /* > >> + * When we get a SIGKILL our release function will > >> + * be called. That will stop new IOs from being queued > >> + * and check for outstanding cmd responses. It will then > >> + * call vhost_task_stop to tell us to return and exit. >
2023 May 23
2
[PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
...e, node) { > clear_bit(VHOST_WORK_QUEUED, &work->flags); > > I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, > vhost_work_queue() can add this work again and change work->node->next. > > That is why we use _safe, but we need to ensure that llist_for_each_safe() > completes LOAD(work->node->next) before VHOST_WORK_QUEUED is cleared. > > So it seems that smp_wmb() can't help and should be removed, instead we need > > llist_for_each_entry_safe(...) { > smp_mb__before_atomic(); > clear_bit(VHOST_WORK_QUEUED, &work...
2023 Jun 01
1
[PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
...t; > > > >I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, > > > > >vhost_work_queue() can add this work again and change work->node->next. > > > > > > > > > >That is why we use _safe, but we need to ensure that llist_for_each_safe() > > > > >completes LOAD(work->node->next) before VHOST_WORK_QUEUED is cleared. > > > > > > > > This should be fine since store is not speculated, so work->node->next needs > > > > to be loaded before VHOST_WORK_QUEUED is cleared to m...