Jesper Dangaard Brouer 039930945a xdp: transition into using xdp_frame for return API ... Changing API xdp_return_frame() to take struct xdp_frame as argument, seems like a natural choice. But there are some subtle performance details here that needs extra care, which is a deliberate choice. When de-referencing xdp_frame on a remote CPU during DMA-TX completion, result in the cache-line is change to "Shared" state. Later when the page is reused for RX, then this xdp_frame cache-line is written, which change the state to "Modified". This situation already happens (naturally) for, virtio_net, tun and cpumap as the xdp_frame pointer is the queued object. In tun and cpumap, the ptr_ring is used for efficiently transferring cache-lines (with pointers) between CPUs. Thus, the only option is to de-referencing xdp_frame. It is only the ixgbe driver that had an optimization, in which it can avoid doing the de-reference of xdp_frame. The driver already have TX-ring queue, which (in case of remote DMA-TX completion) have to be transferred between CPUs anyhow. In this data area, we stored a struct xdp_mem_info and a data pointer, which allowed us to avoid de-referencing xdp_frame. To compensate for this, a prefetchw is used for telling the cache coherency protocol about our access pattern. My benchmarks show that this prefetchw is enough to compensate the ixgbe driver. V7: Adjust for commit d9314c474d ("i40e: add support for XDP_REDIRECT") V8: Adjust for commit bd658dda42 ("net/mlx5e: Separate dma base address and offset in dma_sync call") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2018-04-17 10:50:29 -04:00
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bpf	xdp: transition into using xdp_frame for return API	2018-04-17 10:50:29 -04:00
cgroup	Merge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2018-04-03 18:00:13 -07:00
configs	KVM changes for 4.16	2018-02-10 13:16:35 -08:00
debug	* Fix 2032 time access issues and new compiler warnings	2018-04-12 10:21:19 -07:00
events	perf/x86/pt, coresight: Clean up address filter structure	2018-03-29 16:07:22 +02:00
gcov	…
irq	genirq: Make GENERIC_IRQ_MULTI_HANDLER depend on !MULTI_IRQ_HANDLER	2018-04-04 12:04:28 +02:00
livepatch	Merge branch 'for-4.16/remove-immediate' into for-linus	2018-01-31 16:36:38 +01:00
locking	locking/rwsem: Add DEBUG_RWSEMS to look for lock/unlock mismatches	2018-03-31 07:30:50 +02:00
power	PM / QoS: mark expected switch fall-throughs	2018-04-09 13:49:40 +02:00
printk	New features:	2018-04-10 11:27:30 -07:00
rcu	Merge branches 'fixes.2018.02.23a', 'srcu.2018.02.20a' and 'torture.2018.02.20a' into HEAD	2018-02-23 15:15:41 -08:00
sched	More power management updates for 4.17-rc1	2018-04-11 17:03:20 -07:00
time	* Fix 2032 time access issues and new compiler warnings	2018-04-12 10:21:19 -07:00
trace	New features:	2018-04-10 11:27:30 -07:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	error-injection: Support fault injection framework	2018-01-12 17:33:38 -08:00
acct.c	kernel/acct.c: fix the acct->needcheck check in check_free_space()	2018-01-04 16:45:09 -08:00
async.c	kernel/async.c: revert "async: simplify lowest_in_progress()"	2018-02-06 18:32:44 -08:00
audit.c	audit/stable-4.17 PR 20180403	2018-04-06 15:01:25 -07:00
audit.h	audit: track the owner of the command mutex ourselves	2018-02-23 11:22:22 -05:00
audit_fsnotify.c	…
audit_tree.c	audit: track the owner of the command mutex ourselves	2018-02-23 11:22:22 -05:00
audit_watch.c	…
auditfilter.c	audit: deprecate the AUDIT_FILTER_ENTRY filter	2018-02-15 14:36:29 -05:00
auditsc.c	audit: bail before bug check if audit disabled	2018-02-15 14:40:25 -05:00
backtracetest.c	…
bounds.c	…
capability.c	…
compat.c	mm: add kernel_move_pages() helper, move compat syscall to mm/migrate.c	2018-04-02 20:15:32 +02:00
configs.c	…
context_tracking.c	…
cpu.c	cpu/hotplug: Fix unused function warning	2018-03-15 20:34:40 +01:00
cpu_pm.c	…
crash_core.c	crash: export paddr_vmcoreinfo_note()	2018-03-20 03:17:41 +02:00
crash_dump.c	…
cred.c	…
delayacct.c	delayacct: Account blkio completion on the correct task	2018-01-16 03:29:36 +01:00
dma.c	…
elfcore.c	…
exec_domain.c	get rid of pointless includes of fs_struct.h	2018-02-22 14:28:50 -05:00
exit.c	kernel: use kernel_wait4() instead of sys_wait4()	2018-04-02 20:14:51 +02:00
extable.c	extable: Make init_kernel_text() global	2018-02-21 16:54:06 +01:00
fail_function.c	error-injection: Fix to prohibit jump optimization	2018-03-12 16:16:00 +01:00
fork.c	kernel/fork.c: detect early free of a live mm	2018-04-05 21:36:27 -07:00
freezer.c	…
futex.c	pids: introduce find_get_task_by_vpid() helper	2018-02-06 18:32:46 -08:00
futex_compat.c	…
groups.c	kernel: make groups_sort calling a responsibility group_info allocators	2017-12-14 16:00:49 -08:00
hung_task.c	…
irq_work.c	irq/work: Improve the flag definitions	2018-01-08 19:43:15 +01:00
jump_label.c	jump_label: Disable jump labels in __exit code	2018-03-20 08:57:17 +01:00
kallsyms.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk	2018-02-01 13:36:15 -08:00
kcmp.c	…
kcov.c	kcov: detect double association with a single task	2018-02-06 18:32:46 -08:00
kexec.c	kexec: call do_kexec_load() in compat syscall directly	2018-04-02 20:15:01 +02:00
kexec_core.c	…
kexec_file.c	…
kexec_internal.h	…
kmod.c	…
kprobes.c	kprobes: Propagate error from disarm_kprobe_ftrace()	2018-02-16 09:12:58 +01:00
ksysfs.c	…
kthread.c	…
latencytop.c	…
memremap.c	kernel/memremap: Remove stale devres_free() call	2018-03-06 10:58:54 -08:00
module-internal.h	…
module.c	arch: remove obsolete architecture ports	2018-04-02 20:20:12 -07:00
module_signing.c	…
notifier.c	…
nsproxy.c	…
padata.c	padata: add SPDX identifier	2018-01-05 18:43:00 +11:00
panic.c	taint: add taint for randstruct	2018-04-11 10:28:35 -07:00
params.c	kernel/params.c: downgrade warning for unsafe parameters	2018-04-11 10:28:37 -07:00
pid.c	xarray: add the xa_lock to the radix_tree_root	2018-04-11 10:28:39 -07:00
pid_namespace.c	Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2018-04-03 19:15:32 -07:00
profile.c	…
ptrace.c	pids: introduce find_get_task_by_vpid() helper	2018-02-06 18:32:46 -08:00
range.c	…
reboot.c	…
relay.c	kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE	2018-02-21 15:35:43 -08:00
resource.c	Merge branch 'akpm' (patches from Andrew)	2018-02-06 22:15:42 -08:00
seccomp.c	- Fix seccomp GET_METADATA to deal with field sizes correctly (Tycho Andersen)	2018-02-22 10:50:24 -08:00
signal.c	Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2018-04-07 11:11:41 -07:00
smp.c	…
smpboot.c	…
smpboot.h	…
softirq.c	softirq: Consolidate common code in tasklet_[hi]_action()	2018-03-09 11:50:55 +01:00
stacktrace.c	…
stop_machine.c	…
sys.c	kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid()	2018-04-02 20:16:06 +02:00
sys_ni.c	kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions	2018-04-02 20:16:20 +02:00
sysctl.c	kernel/sysctl.c: add kdoc comments to do_proc_do{u}intvec_minmax_conv_param	2018-04-11 10:28:38 -07:00
sysctl_binary.c	…
task_work.c	locking/barriers: Convert users of lockless_dereference() to READ_ONCE()	2017-12-17 13:57:15 +01:00
taskstats.c	pids: introduce find_get_task_by_vpid() helper	2018-02-06 18:32:46 -08:00
test_kprobes.c	…
torture.c	torture: Save a line in stutter_wait(): while -> for	2017-12-11 09:18:30 -08:00
tracepoint.c	tracepoint: Remove smp_read_barrier_depends() from comment	2017-12-04 10:52:56 -08:00
tsacct.c	…
ucount.c	headers: untangle kmemleak.h from mm.h	2018-04-05 21:36:27 -07:00
uid16.c	fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers	2018-04-02 20:15:59 +02:00
uid16.h	kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c	2018-04-02 20:15:30 +02:00
umh.c	kernel: use kernel_wait4() instead of sys_wait4()	2018-04-02 20:14:51 +02:00
up.c	…
user-return-notifier.c	…
user.c	efivarfs: Limit the rate for non-root to read files	2018-02-22 10:21:02 -08:00
user_namespace.c	…
utsname.c	uts: create "struct uts_namespace" from kmem_cache	2018-04-11 10:28:35 -07:00
utsname_sysctl.c	…
watchdog.c	…
watchdog_hld.c	…
workqueue.c	Merge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2018-04-03 18:00:13 -07:00
workqueue_internal.h	…