Eric Dumazet 7aef5082c5 once: add DO_ONCE_SLOW() for sleepable contexts ... [ Upstream commit 62c07983be ] Christophe Leroy reported a ~80ms latency spike happening at first TCP connect() time. This is because __inet_hash_connect() uses get_random_once() to populate a perturbation table which became quite big after commit 4c2c8f03a5 ("tcp: increase source port perturb table to 2^16") get_random_once() uses DO_ONCE(), which block hard irqs for the duration of the operation. This patch adds DO_ONCE_SLOW() which uses a mutex instead of a spinlock for operations where we prefer to stay in process context. Then __inet_hash_connect() can use get_random_slow_once() to populate its perturbation table. Fixes: 4c2c8f03a5 ("tcp: increase source port perturb table to 2^16") Fixes: 190cc82489 ("tcp: change source port randomizarion at connect() time") Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/netdev/CANn89iLAEYBaoYajy0Y9UmGFff5GPxDUoG-ErVB2jDdRNQ5Tug@mail.gmail.com/T/#t Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willy Tarreau <w@1wt.eu> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-10-26 12:34:49 +02:00
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acpi	ACPI: CPPC: Do not prevent CPPC from working in the future	2022-08-17 14:24:25 +02:00
asm-generic	vmlinux.lds.h: CFI: Reduce alignment of jump-table to function alignment	2022-09-28 11:11:45 +02:00
clocksource	…
crypto	crypto: blake2s - remove shash module	2022-08-17 14:24:19 +02:00
drm	drm/bridge: Add stubs for devm_drm_of_get_bridge when OF is disabled	2022-09-05 10:30:03 +02:00
dt-bindings	clk: qcom: gcc-msm8939: Add missing SYSTEM_MM_NOC_BFDCD_CLK_SRC	2022-08-17 14:23:45 +02:00
keys	…
kunit	…
kvm	…
linux	once: add DO_ONCE_SLOW() for sleepable contexts	2022-10-26 12:34:49 +02:00
math-emu	…
media	…
memory	…
misc	…
net	tcp: fix tcp_cwnd_validate() to not forget is_cwnd_limited	2022-10-26 12:34:48 +02:00
pcmcia	…
ras	Revert "mm/memory-failure.c: fix race with changing page compound again"	2022-07-12 16:35:17 +02:00
rdma	…
scsi	scsi: stex: Properly zero out the passthrough command structure	2022-10-15 07:59:01 +02:00
soc	ARM: at91: ddr: remove CONFIG_SOC_SAMA7 dependency	2022-09-15 11:30:08 +02:00
sound	ALSA: control: Use deferred fasync helper	2022-08-25 11:40:44 +02:00
target	…
trace	tracing/perf: Avoid -Warray-bounds warning for __rel_loc macro	2022-08-17 14:24:30 +02:00
uapi	btrfs: remove no longer needed logic for replaying directory deletes	2022-09-05 10:30:09 +02:00
vdso	…
video	video: of_display_timing.h: include errno.h	2022-07-12 16:35:10 +02:00
xen	…