linux/include
Eric Dumazet 4725344462 time/timecounter: Inline timecounter_cyc2time()
New network transport protocols want NIC drivers to get hardware timestamps
of all incoming packets, and possibly all outgoing packets.

One example is the upcoming 'Swift congestion control' which is used by TCP
transport and is the primary need for timecounter_cyc2time(). This means
timecounter_cyc2time() can be called more than 100 million times per second
on a busy server.

Inlining timecounter_cyc2time() brings a 12% improvement on a UDP receive
stress test on a 100Gbit NIC.

Note that FDO, LTO, PGO are unable to magically help for this case,
presumably because NIC drivers are almost exclusively shipped as modules.

Add an unlikely() around the cc_cyc2ns_backwards() case, even if FDO (when
used) is able to take care of this optimization.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://research.google/pubs/swift-delay-is-simple-and-effective-for-congestion-control-in-the-datacenter/
Link: https://patch.msgid.link/20251129095740.3338476-1-edumazet@google.com
2025-12-15 20:16:49 +01:00
..
acpi
asm-generic hyperv-next for v6.19 2025-12-09 06:10:17 +09:00
clocksource
crypto This update includes the following changes: 2025-12-03 11:28:38 -08:00
cxl
drm Cross-subsystem Changes: 2025-12-05 10:16:25 +10:00
dt-bindings This pull request is entirely SoC clk drivers, not for lack of trying to modify 2025-12-08 09:38:52 +09:00
hyperv mshv: Add definitions for MSHV sleep state configuration 2025-12-05 23:24:57 +00:00
keys
kunit
kvm
linux time/timecounter: Inline timecounter_cyc2time() 2025-12-15 20:16:49 +01:00
math-emu
media
memory
misc
net - fix a bug with O_APPEND in cached mode causing data to be written multiple times on server 2025-12-07 08:29:09 -08:00
pcmcia
ras Significant patch series in this merge are as follows: 2025-12-05 13:52:43 -08:00
rdma
rv
scsi
soc This pull request is entirely SoC clk drivers, not for lack of trying to modify 2025-12-08 09:38:52 +09:00
sound soundwire updates for 6.19 2025-12-13 16:26:55 +12:00
target
trace We have a patch that adds an initial set of tracepoints to the MDS 2025-12-14 15:24:10 +12:00
uapi sound fixes for 6.19-rc1 2025-12-13 16:09:10 +12:00
ufs
vdso
video
xen
Kbuild