Mel Gorman
d0164adc89
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd ...
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
9p: switch p9_client_read() to passing struct iov_iter *
2015-04-11 22:28:27 -04:00
Bluetooth: Rename bt_cb()->req into bt_cb()->hci
2015-10-26 08:21:03 +02:00
caif: fix a signedness bug in cfpkt_iterate()
2015-02-20 17:35:14 -05:00
irda: Convert function pointer arrays and uses to const
2014-12-10 15:33:16 -05:00
s390/iucv: do not use arrays as argument
2015-09-21 16:03:04 -07:00
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2015-10-17 14:28:03 +02:00
Revert "ipv4/icmp: redirect messages can use the ingress daddr as source"
2015-10-14 06:01:07 -07:00
NFC: nci: non-static functions can not be inline
2015-10-28 06:44:45 +01:00
sctp: fix ASCONF list handling
2015-06-14 12:55:49 -07:00
act_connmark: Remember the struct net instead of guessing it.
2015-09-18 21:59:31 +02:00
6lowpan: remove lowpan_is_addr_broadcast
2015-10-21 00:49:25 +02:00
net_sched: make tcf_hash_destroy() static
2015-08-26 11:01:44 -07:00
ipv6: remove unused neigh parameter from ndisc functions
2015-09-24 12:26:08 -07:00
ieee802154: af_ieee802154: fix typo in comment.
2015-09-17 13:20:05 +02:00
af_unix: constify the sock parameter in unix_sk()
2015-10-08 04:05:18 -07:00
VSOCK: define VSOCK_SS_LISTEN once only
2015-11-01 12:14:47 -05:00
ipsec: Remove obsolete MAX_AH_AUTH_LEN
2014-09-18 10:54:36 +02:00
neigh: Factor out ___neigh_lookup_noref
2015-03-04 00:23:23 -05:00
ax25: Stop using sock->sk_protinfo.
2015-06-28 16:55:44 -07:00
bonding: simplify / unify event handling code for 3ad mode.
2015-11-02 22:52:24 -05:00
net: Move bonding headers under include/net
2014-11-10 13:27:49 -05:00
bonding: convert num_grat_arp to the new bonding option API
2015-07-27 01:05:24 -07:00
net/bonding: Export bond_option_active_slave_get_rcu
2015-08-30 18:08:50 -04:00
cfg80211/mac80211: clarify RSSI CQM reporting requirements
2015-11-03 10:54:58 +01:00
nl802154: add support for security layer
2015-09-30 13:16:44 +02:00
net: Add inet_proto_csum_replace_by_diff utility function
2015-08-17 21:33:06 -07:00
cipso: don't use IPCB() to locate the CIPSO IP option
2015-02-11 14:46:37 -05:00
cls_cgroup: factor out classid retrieval
2015-07-20 12:41:30 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2015-05-13 14:31:43 -04:00
net: switch importing msghdr from userland to {compat_,}import_iovec()
2015-04-09 00:02:26 -04:00
net/dcb: Add IEEE QCN attribute
2015-03-06 21:50:02 -05:00
netfilter: Pass net into okfn
2015-09-17 17:18:37 -07:00
net: dsa: use switchdev obj for VLAN add/del ops
2015-11-01 15:56:11 -05:00
dst: Pass net into dst->output
2015-10-08 04:27:03 -07:00
openvswitch: Fix egress tunnel info.
2015-10-22 19:39:25 -07:00
ipv4, ipv6: Pass net into __ip_local_out and __ip6_local_out
2015-10-08 04:27:02 -07:00
net/ethoc: support big-endian register layout
2015-09-23 15:33:15 -07:00
net: ipv6: use common fib_default_rule_pref
2015-09-09 14:19:50 -07:00
net: Rename FLOWI_FLAG_VRFSRC to FLOWI_FLAG_L3MDEV_SRC
2015-10-07 04:27:42 -07:00
flow_dissector: Don't use bit fields.
2015-09-01 16:46:08 -07:00
ip_tunnel: Ops registration for secondary encap (fou, gue)
2014-11-12 15:01:35 -05:00
net: sched: enable per cpu qstats
2014-09-30 01:02:26 -04:00
genetlink: simplify genl_notify
2015-09-24 12:25:23 -07:00
geneve: Consolidate Geneve functionality in single module.
2015-08-27 15:42:48 -07:00
gre: Remove support for sharing GRE protocol hook.
2015-08-10 14:03:54 -07:00
gro_cells: remove spinlock protecting receive queues
2015-08-31 15:17:17 -07:00
gue: Protocol constants for remote checksum offload
2014-11-05 16:30:03 -05:00
nl802154: add support for security layer
2015-09-30 13:16:44 +02:00
ipv6: do retries on stable privacy addresses
2015-03-23 22:12:09 -04:00
ipv6: remove obsolete inet6 functions
2015-10-03 04:32:42 -07:00
ipv6: get rid of __inet6_hash()
2015-03-18 22:00:35 -04:00
net: avoid NULL deref in inet_ctl_sock_destroy()
2015-11-02 22:46:09 -05:00
tcp/dccp: fix hashdance race for passive sessions
2015-10-23 05:42:21 -07:00
net: fix percpu memory leaks
2015-11-02 22:47:14 -05:00
tcp/dccp: fix hashdance race for passive sessions
2015-10-23 05:42:21 -07:00
tcp: avoid two atomic ops for syncookies
2015-10-05 02:45:27 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2015-10-20 06:08:27 -07:00
net: Add support for VRFs to inetpeer cache
2015-08-28 13:32:36 -07:00
ipv4: Pass struct net into ip_defrag and ip_check_defrag
2015-10-12 19:44:16 -07:00
net: add gro_compute_pseudo functions
2014-08-24 18:09:23 -07:00
ipv6: include NLM_F_REPLACE in route replace notifications
2015-09-17 15:00:27 -07:00
ipv6: Pass struct net through ip6_fragment
2015-09-30 01:45:03 -05:00
ipv4, ipv6: Pass net into ip_local_out and ip6_local_out
2015-10-08 04:27:02 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2015-11-03 13:41:45 -05:00
ipv4: send arp replies to the correct tunnel
2015-09-24 14:31:36 -07:00
ipvs: Remove skb_sknet
2015-09-24 09:34:43 +09:00
dst: Pass net into dst->output
2015-10-08 04:27:03 -07:00
switch ipxrtr_route_packet() from iovec to msghdr
2014-11-24 04:28:49 -05:00
wext: add checked wrappers for adding events/points to streams
2015-02-28 21:31:12 +01:00
net: Add IPv6 support to l3mdev
2015-10-13 04:55:04 -07:00
lib80211: remove unused print_ssid()
2014-10-14 02:18:27 +02:00
llc: Make llc_conn_ev_qfyr_t function pointer arrays const
2014-12-10 15:21:24 -05:00
net: Pass kern from net_proto_family.create to sk_alloc
2015-05-11 10:50:17 -04:00
llc: Make llc_sap_action_t function pointer arrays const
2014-12-10 15:21:24 -05:00
dst: Pass net into dst->output
2015-10-08 04:27:03 -07:00
mac80211: document sleep requirements for channel context ops
2015-11-03 11:15:48 +01:00
6lowpan: cleanup lowpan_header_decompress
2015-10-21 00:49:24 +02:00
ipv6: mld: answer mldv2 queries with mldv1 reports in mldv1 fallback
2014-09-22 16:23:15 -04:00
openvswitch: Add basic MPLS support to kernel
2014-11-05 23:52:33 -08:00
mpls: multipath route support
2015-10-23 06:26:42 -07:00
ipv6: remove unused neigh parameter from ndisc functions
2015-09-24 12:26:08 -07:00
net: add explicit logging and stat for neighbour table overflow
2015-08-10 13:46:21 -07:00
netfilter: nfacct: per network namespace support
2015-08-07 11:50:56 +02:00
netlabel: fix the netlbl_catmap_setlong() dummy function
2014-08-07 20:55:21 -04:00
netlink: add nla_get for le32 and le64
2015-09-30 13:16:44 +02:00
nl802154: add support for security layer
2015-09-30 13:16:44 +02:00
net: Remove iocb argument from sendmsg and recvmsg
2015-03-02 13:06:31 -05:00
net: sched: remove tcf_proto from ematch calls
2014-10-06 18:02:32 -04:00
net: sched: consolidate tc_classify{,_compat}
2015-08-27 14:18:48 -07:00
cfg80211: allow wiphy specific regdomain management
2014-12-17 11:49:55 +01:00
tcp/dccp: fix race at listener dismantle phase
2015-10-16 00:52:19 -07:00
net: Add source address lookup op for VRF
2015-10-07 04:27:44 -07:00
netlink: Rightsize IFLA_AF_SPEC size calculation
2015-10-21 19:15:20 -07:00
bpf: add bpf_redirect() helper
2015-09-17 21:09:07 -07:00
Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
2014-10-15 07:48:18 +02:00
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
switchdev: introduce possibility to defer obj_add/del
2015-10-15 06:09:49 -07:00
tcp/dccp: fix hashdance race for passive sessions
2015-10-23 05:42:21 -07:00
inet: add TCP_NEW_SYN_RECV state
2015-03-12 22:58:12 -04:00
inet: remove BUG_ON() in twsk_destructor()
2015-07-09 15:12:20 -07:00
net: tso: add support for IPv6
2015-10-26 22:24:22 -07:00
net: Remove iocb argument from sendmsg and recvmsg
2015-03-02 13:06:31 -05:00
vxlan: do not receive IPv4 packets on IPv6 socket
2015-08-29 13:07:54 -07:00
net: switch memcpy_fromiovec()/memcpy_fromiovecend() users to copy_from_iter()
2015-02-04 01:34:15 -05:00
vxlan: support both IPv4 and IPv6 sockets in a single vxlan device
2015-09-26 22:40:55 -07:00
net: treewide: Fix typo found in DocBook/networking.xml
2014-09-05 17:35:28 -07:00
dst: Pass net into dst->output
2015-10-08 04:27:03 -07:00
d0164adc89