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SubjectRe: [RFC][PATCH] PM: Introduce new top level suspend and hibernation callbacks (rev. 2)
On Sunday, 23 of March 2008, Alan Stern wrote:
> On Sat, 22 Mar 2008, Rafael J. Wysocki wrote:
> No, you have missed the entire point. The problem doesn't exist in the
> current code; it exists only if we switch over to using a single list.
> Routines like dpm_suspend() won't be able to use list_for_each_entry()
> to traverse the list because entries may be removed by other threads
> during the traversal. Even list_for_each_entry_safe() won't work
> correctly without careful attention to details.

Ah, ok. Thanks for the clarification.

Doesn't it help that we traverse the list under dpm_list_mtx? Anyone who
removes an entry is required to take dpm_list_mtx that we're holding while
the list is traversed except when the callbacks are invoked.

The only problem I see is when the device currently being handled is removed
from the list by a concurrent thread. Is that you were referring to?


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