linux_dsm_epyc7002/fs/nfs
NeilBrown f682a398b2 NFS: allow lockless access to access_cache
The access cache is used during RCU-walk path lookups, so it is best
to avoid locking if possible as taking a lock kills concurrency.

The rbtree is not rcu-safe and cannot easily be made so.
Instead we simply check the last (i.e. most recent) entry on the LRU
list.  If this doesn't match, then we return -ECHILD and retry in
lock/refcount mode.

This requires freeing the nfs_access_entry struct with rcu, and
requires using rcu access primatives when adding entries to the lru, and
when examining the last entry.

Calling put_rpccred before kfree_rcu looks a bit odd, but as
put_rpccred already provides rcu protection, we know that the cred will
not actually be freed until the next grace period, so any concurrent
access will be safe.

This patch provides about 5% performance improvement on a stat-heavy
synthetic work load with 4 threads on a 2-core CPU.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-08-03 17:14:13 -04:00
..
blocklayout FS/NFS: replace count*size kzalloc by kcalloc 2014-06-25 19:02:14 -04:00
filelayout nfs: clear_request_commit while holding i_lock 2014-08-03 17:05:26 -04:00
objlayout nfs: remove unused writeverf code 2014-06-24 18:47:00 -04:00
cache_lib.c NFS: simplify and clean cache library 2013-02-15 10:43:36 -05:00
cache_lib.h NFS: simplify and clean cache library 2013-02-15 10:43:36 -05:00
callback_proc.c NFSv4.1: Minor optimisation in get_layout_by_fh_locked() 2014-02-19 21:21:06 -05:00
callback_xdr.c Merge branch 'labeled-nfs' into linux-next 2013-06-28 16:29:51 -04:00
callback.c nfs4: copy acceptor name from context to nfs_client 2014-07-12 18:41:25 -04:00
callback.h NFS: Add in v4.2 callback operation 2013-06-08 16:20:18 -04:00
client.c NFS: add checks for returned value of try_module_get() 2014-08-03 17:14:10 -04:00
delegation.c nfs4: add nfs4_check_delegation 2014-07-12 18:22:58 -04:00
delegation.h nfs4: add nfs4_check_delegation 2014-07-12 18:22:58 -04:00
dir.c NFS: allow lockless access to access_cache 2014-08-03 17:14:13 -04:00
direct.c Merge branch 'bugfixes' into linux-next 2014-07-13 15:22:02 -04:00
dns_resolve.c NFS: Enabling v4.2 should not recompile nfsd and lockd 2013-11-19 16:20:40 -05:00
dns_resolve.h
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
fscache-index.c
fscache.c NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open() 2013-09-27 18:40:25 +01:00
fscache.h NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open() 2013-09-27 18:40:25 +01:00
getroot.c NFS: Fix memroy leak for double mounts 2014-04-15 10:29:25 -04:00
idmap.c NFSv4: Convert idmapper to use the new framework for pipefs dentries 2013-09-01 11:12:42 -04:00
inode.c NFS: teach nfs_neg_need_reval to understand LOOKUP_RCU 2014-08-03 17:14:12 -04:00
internal.h Merge branch 'bugfixes' into linux-next 2014-07-13 15:22:02 -04:00
iostat.h
Kconfig nfs: fix pnfs Kconfig defaults 2013-11-15 13:41:43 -05:00
Makefile Push the file layout driver into a subdirectory 2014-05-29 20:21:56 -04:00
mount_clnt.c nfs: have nfs_mount fake up a auth_flavs list when the server didn't provide it 2013-06-28 15:51:51 -04:00
namespace.c nfs: use %p[dD] instead of open-coded (and often racy) equivalents 2013-10-24 23:34:50 -04:00
netns.h nfs: include NFSv4 header in netns.h 2012-10-02 08:17:02 -07:00
nfs2super.c NFS: Convert v2 into a module 2012-07-30 19:06:41 -04:00
nfs2xdr.c NFS: Create a common results structure for reads and writes 2014-05-28 18:12:43 -04:00
nfs3acl.c nfs3_list_one_acl(): check get_acl() result with IS_ERR_OR_NULL 2014-08-03 17:05:22 -04:00
nfs3client.c NFS: Only initialize the ACL client in the v3 case 2012-07-30 19:05:54 -04:00
nfs3proc.c Merge branch 'bugfixes' into linux-next 2014-07-13 15:22:02 -04:00
nfs3super.c nfs: use generic posix ACL infrastructure for v3 Posix ACLs 2014-01-26 08:26:20 -05:00
nfs3xdr.c NFS: Create a common results structure for reads and writes 2014-05-28 18:12:43 -04:00
nfs4_fs.h nfs4: turn free_lock_state into a void return operation 2014-07-12 18:36:37 -04:00
nfs4client.c nfsv4: set hostname when creating nfsv4 ds connection 2014-07-08 14:30:03 -04:00
nfs4file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-06-12 10:30:18 -07:00
nfs4getroot.c NFSv4: Fix security auto-negotiation 2013-09-07 16:18:30 -04:00
nfs4namespace.c NFSv4: test SECINFO RPC_AUTH_GSS pseudoflavors for support 2014-06-24 18:46:58 -04:00
nfs4proc.c NFS: nfs4_do_open should add negative results to the dcache. 2014-08-03 17:05:22 -04:00
nfs4renewd.c workqueue: use mod_delayed_work() instead of cancel + queue 2012-08-13 16:27:37 -07:00
nfs4session.c NFSv4.1: nfs4_destroy_session must call rpc_destroy_waitqueue 2014-02-01 15:13:39 -05:00
nfs4session.h NFSv4.1: nfs4_destroy_session must call rpc_destroy_waitqueue 2014-02-01 15:13:39 -05:00
nfs4state.c nfs4: queue free_lock_state job submission to nfsiod 2014-07-12 18:36:35 -04:00
nfs4super.c mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
nfs4sysctl.c nfs: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
nfs4trace.c NFSv4.1: Add tracepoints for debugging slot table operations 2013-08-22 08:58:27 -04:00
nfs4trace.h nfs: merge nfs_pgio_data into _header 2014-06-24 18:47:00 -04:00
nfs4xdr.c NFSv4: Drop cast 2014-07-12 18:43:47 -04:00
nfs.h NFS: Convert v4 into a module 2012-07-30 19:06:52 -04:00
nfsroot.c
nfstrace.c NFS: Add event tracing for generic NFS lookups 2013-08-22 08:58:18 -04:00
nfstrace.h NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping 2014-01-27 15:35:56 -05:00
pagelist.c nfs: check wait_on_bit_lock err in page_group_lock 2014-08-03 17:05:24 -04:00
pnfs_dev.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
pnfs.c pnfs: add pnfs_put_lseg_async 2014-08-03 17:05:25 -04:00
pnfs.h pnfs: add pnfs_put_lseg_async 2014-08-03 17:05:25 -04:00
proc.c nfs: merge nfs_pgio_data into _header 2014-06-24 18:47:00 -04:00
read.c nfs: get rid of duplicate dprintk 2014-06-25 19:01:27 -04:00
super.c NFS: use ARRAY_SIZE instead of sizeof/sizeof[0] 2014-07-12 18:43:58 -04:00
symlink.c
sysctl.c nfs: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
unlink.c nfs: emit a fsnotify_nameremove call in sillyrename codepath 2014-03-17 15:14:17 -04:00
write.c nfs: clear_request_commit while holding i_lock 2014-08-03 17:05:26 -04:00