This patch series implements the memory shrinker for NFSv4 clients
to react to system low memory condition.
The first patch adds a counter to keep track of the number of
courtesy clients in the system.
The second patch implements the courtesy_client_reaper used to
expiring the courtesy clients.
By destroying the courtesy clients, all states associated with
these clients are also released.
v2:
. fix kernel test robot errors in nfsd.h when CONFIG_NFSD_V4 not defined.
v3:
. add mod_delayed_work in nfsd_courtesy_client_scan to kick start
the laundromat.
v4:
. replace the use of xchg() with vanilla '=' in patch 1.
v5:
. rename nfsd_courtesy_client_count to nfsd_courtesy_clients
. add helper nfsd4_update_courtesy_client_count
. move nfsd_register_client_shrinker into nfsd4_init_leases_net
. move nfsd4_leases_net_shutdown from nfsd.h to nfs4state.c
. do away with shrinker 'scan' callback, just return SHRINK_STOP
. remove unused nfsd_client_shrinker_reapcount
v6:
. create courtesy_client_reaper and a separate delayed_work for it
using the laundromat_wq.
I tried merging nfs4_get_courtesy_client_reaplist and
nfs4_get_client_reaplist but it make the code looks ugly and
hard to read so I leave them separate for now.
---
Dai Ngo (2):
NFSD: keep track of the number of courtesy clients in the system
NFSD: add shrinker to reap courtesy clients on low memory condition
fs/nfsd/netns.h | 5 ++
fs/nfsd/nfs4state.c | 119 +++++++++++++++++++++++++++++++++++++++++++----
fs/nfsd/nfsctl.c | 6 ++-
fs/nfsd/nfsd.h | 7 ++-
4 files changed, 124 insertions(+), 13 deletions(-)