Chao Gao 4ef9951d02 dma-direct: avoid redundant memory sync for swiotlb ... commit 9e02977bfa upstream. When we looked into FIO performance with swiotlb enabled in VM, we found swiotlb_bounce() is always called one more time than expected for each DMA read request. It turns out that the bounce buffer is copied to original DMA buffer twice after the completion of a DMA request (one is done by in dma_direct_sync_single_for_cpu(), the other by swiotlb_tbl_unmap_single()). But the content in bounce buffer actually doesn't change between the two rounds of copy. So, one round of copy is redundant. Pass DMA_ATTR_SKIP_CPU_SYNC flag to swiotlb_tbl_unmap_single() to skip the memory copy in it. This fix increases FIO 64KB sequential read throughput in a guest with swiotlb=force by 5.6%. Fixes: 55897af630 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code") Reported-by: Wang Zhaoyang1 <zhaoyang1.wang@intel.com> Reported-by: Gao Liang <liang.gao@intel.com> Signed-off-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-04-20 09:34:21 +02:00
..
bpf	bpf: Adjust BPF stack helper functions to accommodate skip > 0	2022-04-08 14:24:14 +02:00
cgroup	cgroup-v1: Correct privileges check in release_agent writes	2022-03-02 11:47:47 +01:00
configs	drivers/char: remove /dev/kmem for good	2021-05-07 00:26:34 -07:00
debug	kdb: Fix the putarea helper function	2022-04-08 14:23:51 +02:00
dma	dma-direct: avoid redundant memory sync for swiotlb	2022-04-20 09:34:21 +02:00
entry	signal: Replace force_fatal_sig with force_exit_sig when in doubt	2021-11-25 09:49:07 +01:00
events	perf/core: Inherit event_caps	2022-04-13 20:59:24 +02:00
gcov	Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTR	2021-06-22 11:07:18 -07:00
irq	genirq/affinity: Consider that CPUs on nodes can be unbalanced	2022-04-20 09:34:20 +02:00
kcsan	LKMM updates:	2021-09-02 13:00:15 -07:00
livepatch	livepatch: Fix build failure on 32 bits processors	2022-04-08 14:23:29 +02:00
locking	locking/lockdep: Iterate lock_classes directly when reading lockdep files	2022-04-08 14:23:57 +02:00
power	PM: suspend: fix return value of __setup handler	2022-04-08 14:23:07 +02:00
printk	printk: fix return value of printk.devkmsg __setup handler	2022-04-08 14:23:19 +02:00
rcu	rcu: Mark writes to the rcu_segcblist structure's ->flags field	2022-04-08 14:23:55 +02:00
sched	sched: Teach the forced-newidle balancer about CPU affinity limitation.	2022-04-13 20:59:27 +02:00
time	timers: Fix warning condition in __run_timers()	2022-04-20 09:34:21 +02:00
trace	tracing: Have type enum modifications copy the strings	2022-04-08 14:24:13 +02:00
.gitignore	.gitignore: prefix local generated files with a slash	2021-05-02 00:43:35 +09:00
acct.c	kernel/acct.c: use dedicated helper to access rlimit values	2021-09-08 11:50:26 -07:00
async.c	Revert "module, async: async_synchronize_full() on module init iff async is used"	2022-02-23 12:03:07 +01:00
audit.c	audit: improve audit queue handling when "audit=1" on cmdline	2022-02-08 18:34:03 +01:00
audit.h	audit: log AUDIT_TIME_* records only from rules	2022-04-08 14:23:06 +02:00
audit_fsnotify.c
audit_tree.c	audit: move put_tree() to avoid trim_trees refcount underflow and UAF	2021-08-24 18:52:36 -04:00
audit_watch.c
auditfilter.c
auditsc.c	audit: log AUDIT_TIME_* records only from rules	2022-04-08 14:23:06 +02:00
backtracetest.c
bounds.c
capability.c
cfi.c	cfi: Use rcu_read_{un}lock_sched_notrace	2021-08-11 13:11:12 -07:00
compat.c	arch: remove compat_alloc_user_space	2021-09-08 15:32:35 -07:00
configs.c
context_tracking.c
cpu.c	sched/scs: Reset task stack state in bringup_cpu()	2021-12-01 09:04:54 +01:00
cpu_pm.c	PM: cpu: Make notifier chain use a raw_spinlock_t	2021-08-16 18:55:32 +02:00
crash_core.c	kernel/crash_core: suppress unknown crashkernel parameter warning	2021-12-29 12:28:49 +01:00
crash_dump.c
cred.c	ucounts: Base set_cred_ucounts changes on the real user	2022-02-23 12:03:20 +01:00
delayacct.c	delayacct: Add sysctl to enable at runtime	2021-05-12 11:43:25 +02:00
dma.c
exec_domain.c
exit.c	io_uring: remove files pointer in cancellation functions	2021-08-23 13:10:37 -06:00
extable.c
fail_function.c
fork.c	sched: Fix yet more sched_fork() races	2022-03-08 19:12:49 +01:00
freezer.c	sched: Add get_current_state()	2021-06-18 11:43:08 +02:00
futex.c	futex: Remove unused variable 'vpid' in futex_proxy_trylock_atomic()	2021-09-03 23:00:22 +02:00
gen_kheaders.sh	kbuild: clean up ${quiet} checks in shell scripts	2021-05-27 04:01:50 +09:00
groups.c
hung_task.c	Merge branch 'akpm' (patches from Andrew)	2021-07-02 12:08:10 -07:00
iomem.c
irq_work.c	irq_work: Make irq_work_queue() NMI-safe again	2021-06-10 10:00:08 +02:00
jump_label.c	jump_label: Fix jump_label_text_reserved() vs __init	2021-07-05 10:46:20 +02:00
kallsyms.c	module: add printk formats to add module build ID to stacktraces	2021-07-08 11:48:22 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/rwlock: Provide RT variant	2021-08-17 17:50:51 +02:00
Kconfig.preempt	sched/core: Disable CONFIG_SCHED_CORE by default	2021-06-28 22:43:05 +02:00
kcov.c
kexec.c	kexec: avoid compat_alloc_user_space	2021-09-08 15:32:34 -07:00
kexec_core.c	Merge branch 'rework/printk_safe-removal' into for-linus	2021-08-30 16:36:10 +02:00
kexec_elf.c
kexec_file.c	kernel: kexec_file: fix error return code of kexec_calculate_store_digests()	2021-05-07 00:26:32 -07:00
kexec_internal.h
kheaders.c
kmod.c	modules: add CONFIG_MODPROBE_PATH	2021-05-07 00:26:33 -07:00
kprobes.c	kprobes: Limit max data_size of the kretprobe instances	2021-12-08 09:04:41 +01:00
ksysfs.c
kthread.c	Merge branch 'akpm' (patches from Andrew)	2021-06-29 17:29:11 -07:00
latencytop.c
Makefile	static_call: Don't make __static_call_return0 static	2022-04-13 20:59:28 +02:00
module-internal.h
module.c	Revert "module, async: async_synchronize_full() on module init iff async is used"	2022-02-23 12:03:07 +01:00
module_signature.c
module_signing.c
notifier.c	notifier: Remove atomic_notifier_call_chain_robust()	2021-08-16 18:55:32 +02:00
nsproxy.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
padata.c	padata: Remove repeated verbose license text	2021-08-27 16:30:18 +08:00
panic.c	Merge branch 'rework/printk_safe-removal' into for-linus	2021-08-30 16:36:10 +02:00
params.c	params: lift param_set_uint_minmax to common code	2021-08-16 14:42:22 +02:00
pid.c	kernel/pid.c: implement additional checks upon pidfd_create() parameters	2021-08-10 12:53:07 +02:00
pid_namespace.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
profile.c	profiling: fix shift-out-of-bounds bugs	2021-09-08 11:50:26 -07:00
ptrace.c	ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE	2022-04-08 14:22:50 +02:00
range.c
reboot.c	reboot: Add hardware protection power-off	2021-06-21 13:08:36 +01:00
regset.c
relay.c
resource.c	kernel/resource: fix kfree() of bootmem memory again	2022-04-08 14:23:43 +02:00
resource_kunit.c
rseq.c	rseq: Remove broken uapi field layout on 32-bit little endian	2022-04-08 14:23:10 +02:00
scftorture.c	scftorture: Avoid NULL pointer exception on early exit	2021-07-27 11:39:30 -07:00
scs.c	scs: Release kasan vmalloc poison in scs_free process	2021-11-18 19:16:29 +01:00
seccomp.c	seccomp: Invalidate seccomp mode to catch death failures	2022-02-16 12:56:38 +01:00
signal.c	signal: In get_signal test for signal_group_exit every time through the loop	2022-03-08 19:12:34 +01:00
smp.c	smp: Fix offline cpu check in flush_smp_call_function_queue()	2022-04-20 09:34:21 +02:00
smpboot.c	smpboot: Replace deprecated CPU-hotplug functions.	2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c	genirq: Change force_irqthreads to a static key	2021-08-10 22:50:07 +02:00
stackleak.c	gcc-plugins/stackleak: Use noinstr in favor of notrace	2022-02-23 12:03:07 +01:00
stacktrace.c	stacktrace: move filter_irq_stacks() to kernel/stacktrace.c	2022-04-13 20:59:28 +02:00
static_call.c	static_call: Don't make __static_call_return0 static	2022-04-13 20:59:28 +02:00
static_call_inline.c	static_call: Don't make __static_call_return0 static	2022-04-13 20:59:28 +02:00
stop_machine.c
sys.c	ucounts: Move RLIMIT_NPROC handling after set_user	2022-02-23 12:03:20 +01:00
sys_ni.c	compat: remove some compat entry points	2021-09-08 15:32:35 -07:00
sysctl-test.c	kernel/sysctl-test: Remove some casts which are no-longer required	2021-06-23 16:41:24 -06:00
sysctl.c	x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting	2022-03-11 12:22:31 +01:00
task_work.c	kasan: record task_work_add() call stack	2021-04-30 11:20:42 -07:00
taskstats.c
test_kprobes.c
torture.c	torture: Replace deprecated CPU-hotplug functions.	2021-08-10 10:48:07 -07:00
tracepoint.c	tracepoint: Fix kerneldoc comments	2021-08-16 11:39:51 -04:00
tsacct.c	taskstats: Cleanup the use of task->exit_code	2022-01-27 11:05:35 +01:00
ucount.c	ucounts: Handle wrapping in is_ucounts_overlimit	2022-02-23 12:03:20 +01:00
uid16.c
uid16.h
umh.c	kernel/umh.c: fix some spelling mistakes	2021-05-07 00:26:34 -07:00
up.c	A set of locking related fixes and updates:	2021-05-09 13:07:03 -07:00
user-return-notifier.c
user.c	fs/epoll: use a per-cpu counter for user's watches count	2021-09-08 11:50:27 -07:00
user_namespace.c	ucounts: Fix systemd LimitNPROC with private users regression	2022-03-08 19:12:42 +01:00
usermode_driver.c	Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2021-07-03 11:41:14 -07:00
utsname.c
utsname_sysctl.c
watch_queue.c	watch_queue: Free the page array when watch_queue is dismantled	2022-04-08 14:24:11 +02:00
watchdog.c	kernel: watchdog: modify the explanation related to watchdog thread	2021-06-29 10:53:46 -07:00
watchdog_hld.c
workqueue.c	workqueue: Fix unbind_workers() VS wq_worker_running() race	2022-01-16 09:12:41 +01:00
workqueue_internal.h	workqueue: Assign a color to barrier work items	2021-08-17 07:49:10 -10:00