edac: core: remove completion-wait for complete with rcu_barrier
Module edac_core.ko uses call_rcu() callbacks in edac_device.c, edac_mc.c and edac_pci.c. They all use a wait_for_completion() scheme, but this scheme it not 100% safe on multiple CPUs. See the _rcu_barrier() implementation which explains why extra precausion is needed. The patch adds a comment about rcu_barrier() and as a precausion calls rcu_barrier(). A maintainer needs to look at removing the wait_for_completion code. [dougthompson@xmission.com: remove the wait_for_completion code] Signed-off-by Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
dd8ef1db87
commit
458e5ff13e
|
@ -356,7 +356,6 @@ static void complete_edac_device_list_del(struct rcu_head *head)
|
||||||
|
|
||||||
edac_dev = container_of(head, struct edac_device_ctl_info, rcu);
|
edac_dev = container_of(head, struct edac_device_ctl_info, rcu);
|
||||||
INIT_LIST_HEAD(&edac_dev->link);
|
INIT_LIST_HEAD(&edac_dev->link);
|
||||||
complete(&edac_dev->removal_complete);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
@ -369,10 +368,8 @@ static void del_edac_device_from_global_list(struct edac_device_ctl_info
|
||||||
*edac_device)
|
*edac_device)
|
||||||
{
|
{
|
||||||
list_del_rcu(&edac_device->link);
|
list_del_rcu(&edac_device->link);
|
||||||
|
|
||||||
init_completion(&edac_device->removal_complete);
|
|
||||||
call_rcu(&edac_device->rcu, complete_edac_device_list_del);
|
call_rcu(&edac_device->rcu, complete_edac_device_list_del);
|
||||||
wait_for_completion(&edac_device->removal_complete);
|
rcu_barrier();
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
|
|
@ -418,16 +418,14 @@ static void complete_mc_list_del(struct rcu_head *head)
|
||||||
|
|
||||||
mci = container_of(head, struct mem_ctl_info, rcu);
|
mci = container_of(head, struct mem_ctl_info, rcu);
|
||||||
INIT_LIST_HEAD(&mci->link);
|
INIT_LIST_HEAD(&mci->link);
|
||||||
complete(&mci->complete);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
static void del_mc_from_global_list(struct mem_ctl_info *mci)
|
static void del_mc_from_global_list(struct mem_ctl_info *mci)
|
||||||
{
|
{
|
||||||
atomic_dec(&edac_handlers);
|
atomic_dec(&edac_handlers);
|
||||||
list_del_rcu(&mci->link);
|
list_del_rcu(&mci->link);
|
||||||
init_completion(&mci->complete);
|
|
||||||
call_rcu(&mci->rcu, complete_mc_list_del);
|
call_rcu(&mci->rcu, complete_mc_list_del);
|
||||||
wait_for_completion(&mci->complete);
|
rcu_barrier();
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
|
|
|
@ -174,7 +174,6 @@ static void complete_edac_pci_list_del(struct rcu_head *head)
|
||||||
|
|
||||||
pci = container_of(head, struct edac_pci_ctl_info, rcu);
|
pci = container_of(head, struct edac_pci_ctl_info, rcu);
|
||||||
INIT_LIST_HEAD(&pci->link);
|
INIT_LIST_HEAD(&pci->link);
|
||||||
complete(&pci->complete);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
@ -185,9 +184,8 @@ static void complete_edac_pci_list_del(struct rcu_head *head)
|
||||||
static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
|
static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
|
||||||
{
|
{
|
||||||
list_del_rcu(&pci->link);
|
list_del_rcu(&pci->link);
|
||||||
init_completion(&pci->complete);
|
|
||||||
call_rcu(&pci->rcu, complete_edac_pci_list_del);
|
call_rcu(&pci->rcu, complete_edac_pci_list_del);
|
||||||
wait_for_completion(&pci->complete);
|
rcu_barrier();
|
||||||
}
|
}
|
||||||
|
|
||||||
#if 0
|
#if 0
|
||||||
|
|
Loading…
Reference in a new issue