Searched hist:"414 c12385d4741e35d88670c6cc2f40a77809734" (Results 1 – 5 of 5) sorted by relevance
| /openbmc/linux/kernel/rcu/ |
| H A D | tiny.c | diff 414c12385d4741e35d88670c6cc2f40a77809734 Wed Apr 13 17:17:25 CDT 2022 Paul E. McKenney <paulmck@kernel.org> rcu: Provide a get_completed_synchronize_rcu() function
It is currently up to the caller to handle stale return values from
get_state_synchronize_rcu(). If poll_state_synchronize_rcu() returned
true once, a grace period has elapsed, regardless of the fact that counter
wrap might cause some future poll_state_synchronize_rcu() invocation to
return false. For example, the caller might store a separate flag that
indicates whether some previous call to poll_state_synchronize_rcu()
determined that the relevant grace period had already ended.
This approach works, but it requires extra storage and is easy to get
wrong. This commit therefore introduces a get_completed_synchronize_rcu()
that returns a cookie that causes poll_state_synchronize_rcu() to always
return true. This already-completed cookie can be stored in place of the
cookie that previously caused poll_state_synchronize_rcu() to return true.
It can also be used to flag a given structure as not having been exposed
to readers, and thus not requiring a grace period to elapse.
This commit is in preparation for polled expedited grace periods.
Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
|
| H A D | rcu.h | diff 414c12385d4741e35d88670c6cc2f40a77809734 Wed Apr 13 17:17:25 CDT 2022 Paul E. McKenney <paulmck@kernel.org> rcu: Provide a get_completed_synchronize_rcu() function
It is currently up to the caller to handle stale return values from
get_state_synchronize_rcu(). If poll_state_synchronize_rcu() returned
true once, a grace period has elapsed, regardless of the fact that counter
wrap might cause some future poll_state_synchronize_rcu() invocation to
return false. For example, the caller might store a separate flag that
indicates whether some previous call to poll_state_synchronize_rcu()
determined that the relevant grace period had already ended.
This approach works, but it requires extra storage and is easy to get
wrong. This commit therefore introduces a get_completed_synchronize_rcu()
that returns a cookie that causes poll_state_synchronize_rcu() to always
return true. This already-completed cookie can be stored in place of the
cookie that previously caused poll_state_synchronize_rcu() to return true.
It can also be used to flag a given structure as not having been exposed
to readers, and thus not requiring a grace period to elapse.
This commit is in preparation for polled expedited grace periods.
Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
|
| H A D | update.c | diff 414c12385d4741e35d88670c6cc2f40a77809734 Wed Apr 13 17:17:25 CDT 2022 Paul E. McKenney <paulmck@kernel.org> rcu: Provide a get_completed_synchronize_rcu() function
It is currently up to the caller to handle stale return values from
get_state_synchronize_rcu(). If poll_state_synchronize_rcu() returned
true once, a grace period has elapsed, regardless of the fact that counter
wrap might cause some future poll_state_synchronize_rcu() invocation to
return false. For example, the caller might store a separate flag that
indicates whether some previous call to poll_state_synchronize_rcu()
determined that the relevant grace period had already ended.
This approach works, but it requires extra storage and is easy to get
wrong. This commit therefore introduces a get_completed_synchronize_rcu()
that returns a cookie that causes poll_state_synchronize_rcu() to always
return true. This already-completed cookie can be stored in place of the
cookie that previously caused poll_state_synchronize_rcu() to return true.
It can also be used to flag a given structure as not having been exposed
to readers, and thus not requiring a grace period to elapse.
This commit is in preparation for polled expedited grace periods.
Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
|
| H A D | tree.c | diff 414c12385d4741e35d88670c6cc2f40a77809734 Wed Apr 13 17:17:25 CDT 2022 Paul E. McKenney <paulmck@kernel.org> rcu: Provide a get_completed_synchronize_rcu() function
It is currently up to the caller to handle stale return values from
get_state_synchronize_rcu(). If poll_state_synchronize_rcu() returned
true once, a grace period has elapsed, regardless of the fact that counter
wrap might cause some future poll_state_synchronize_rcu() invocation to
return false. For example, the caller might store a separate flag that
indicates whether some previous call to poll_state_synchronize_rcu()
determined that the relevant grace period had already ended.
This approach works, but it requires extra storage and is easy to get
wrong. This commit therefore introduces a get_completed_synchronize_rcu()
that returns a cookie that causes poll_state_synchronize_rcu() to always
return true. This already-completed cookie can be stored in place of the
cookie that previously caused poll_state_synchronize_rcu() to return true.
It can also be used to flag a given structure as not having been exposed
to readers, and thus not requiring a grace period to elapse.
This commit is in preparation for polled expedited grace periods.
Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
|
| /openbmc/linux/include/linux/ |
| H A D | rcupdate.h | diff 414c12385d4741e35d88670c6cc2f40a77809734 Wed Apr 13 17:17:25 CDT 2022 Paul E. McKenney <paulmck@kernel.org> rcu: Provide a get_completed_synchronize_rcu() function
It is currently up to the caller to handle stale return values from
get_state_synchronize_rcu(). If poll_state_synchronize_rcu() returned
true once, a grace period has elapsed, regardless of the fact that counter
wrap might cause some future poll_state_synchronize_rcu() invocation to
return false. For example, the caller might store a separate flag that
indicates whether some previous call to poll_state_synchronize_rcu()
determined that the relevant grace period had already ended.
This approach works, but it requires extra storage and is easy to get
wrong. This commit therefore introduces a get_completed_synchronize_rcu()
that returns a cookie that causes poll_state_synchronize_rcu() to always
return true. This already-completed cookie can be stored in place of the
cookie that previously caused poll_state_synchronize_rcu() to return true.
It can also be used to flag a given structure as not having been exposed
to readers, and thus not requiring a grace period to elapse.
This commit is in preparation for polled expedited grace periods.
Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/
Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
|