linux-stable/include
Paul E. McKenney 6be7436d22 rcu: Add rcu_gp_might_be_stalled()
This commit adds rcu_gp_might_be_stalled(), which returns true if there
is some reason to believe that the RCU grace period is stalled.  The use
case is where an RCU free-memory path needs to allocate memory in order
to free it, a situation that should be avoided where possible.

But where it is necessary, there is always the alternative of using
synchronize_rcu() to wait for a grace period in order to avoid the
allocation.  And if the grace period is stalled, allocating memory to
asynchronously wait for it is a bad idea of epic proportions: Far better
to let others use the memory, because these others might actually be
able to free that memory before the grace period ends.

Thus, rcu_gp_might_be_stalled() can be used to help decide whether
allocating memory on an RCU free path is a semi-reasonable course
of action.

Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:02:50 -07:00
..
acpi Additional ACPI updates for 5.7-rc1 2020-04-06 10:35:06 -07:00
asm-generic hyperv-fixes for 5.7-rc1 2020-04-14 11:58:04 -07:00
clocksource
crypto crypto: curve25519 - do not pollute dispatcher based on assembler 2020-04-09 00:01:59 +09:00
drm drm/bridge: analogix_dp: Split bind() into probe() and real bind() 2020-04-09 10:29:35 +02:00
dt-bindings RISC-V Patches for the 5.7 Merge Window, Part 1 2020-04-09 10:51:30 -07:00
keys
kunit
kvm
linux rcu: Add rcu_gp_might_be_stalled() 2020-04-27 11:02:50 -07:00
math-emu
media
misc
net cfg80211: fix kernel-doc notation 2020-04-14 12:40:02 +02:00
pcmcia
ras
rdma
scsi
soc net: mscc: ocelot: fix untagged packet drops when enslaving to vlan aware bridge 2020-04-15 12:27:35 -07:00
sound ALSA: hda: Skip controller resume if not needed 2020-04-13 18:03:16 +02:00
target
trace blk-wbt: Drop needless newlines from tracepoint format strings 2020-04-17 08:21:46 -06:00
uapi flexible-array member convertion patches for 5.7-rc2 2020-04-19 10:34:30 -07:00
vdso
video
xen xen: Use evtchn_type_t as a type for event channels 2020-04-07 12:12:54 +02:00