George Spelvin 3a3947271c bcache: Clean up bch_get_congested() ... There are a few nits in this function. They could in theory all be separate patches, but that's probably taking small commits too far. 1) I added a brief comment saying what it does. 2) I like to declare pointer parameters "const" where possible for documentation reasons. 3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming weight of a 32-bit random number (giving a random integer with mean 16 and variance 8). Passing by reference in a 64-bit variable is silly; just use hweight32(). 4) Its helper function fract_exp_two is unnecessarily tangled. Gcc can optimize the multiply by (1 << x) to a shift, but it can be written in a much more straightforward way at the cost of one more bit of internal precision. Some analysis reveals that this bit is always available. This shrinks the object code for fract_exp_two(x, 6) from 23 bytes: 0000000000000000 <foo1>: 0: 89 f9 mov %edi,%ecx 2: c1 e9 06 shr $0x6,%ecx 5: b8 01 00 00 00 mov $0x1,%eax a: d3 e0 shl %cl,%eax c: 83 e7 3f and $0x3f,%edi f: d3 e7 shl %cl,%edi 11: c1 ef 06 shr $0x6,%edi 14: 01 f8 add %edi,%eax 16: c3 retq To 19: 0000000000000017 <foo2>: 17: 89 f8 mov %edi,%eax 19: 83 e0 3f and $0x3f,%eax 1c: 83 c0 40 add $0x40,%eax 1f: 89 f9 mov %edi,%ecx 21: c1 e9 06 shr $0x6,%ecx 24: d3 e0 shl %cl,%eax 26: c1 e8 06 shr $0x6,%eax 29: c3 retq (Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits; both versions produce the same output.) 5) And finally, the call to bch_get_congested() in check_should_bypass() is separated from the use of the value by multiple tests which could moot the need to compute it. Move the computation down to where it's needed. This also saves a local register to hold the computed value. Signed-off-by: George Spelvin <lkml@sdf.org> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2019-04-24 10:56:27 -06:00
..
accessibility	…
acpi	libnvdimm fixes v5.1-rc6	2019-04-15 16:48:51 -07:00
amba	ARM: 8836/1: drivers: amba: Update component matching to use the CoreSight UCI values.	2019-02-26 11:23:49 +00:00
android	binder: fix race between munmap() and direct reclaim	2019-03-21 06:51:32 +01:00
ata	libata: fix using DMA buffers on stack	2019-03-28 08:16:04 -06:00
atm	…
auxdisplay	auxdisplay: charlcd: make backlight initial state configurable	2019-03-17 08:48:45 +01:00
base	mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock	2019-04-19 09:46:04 -07:00
bcma	…
block	brd: re-enable __GFP_HIGHMEM in brd_insert_page()	2019-04-22 09:48:12 -06:00
bluetooth	Bluetooth: btusb: request wake pin with NOAUTOEN	2019-04-09 17:38:24 -10:00
bus	ARM: SoC driver updates for 5.1	2019-03-06 09:41:12 -08:00
cdrom	Revert "block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers"	2019-04-12 13:35:27 -06:00
char	ipmi: fix sleep-in-atomic in free_user at cleanup SRCU user->release_barrier	2019-04-17 10:29:27 -05:00
clk	clk: imx: Fix PLL_1416X not rounding rates	2019-04-12 14:21:43 -07:00
clocksource	clocksource/drivers/timer-ti-dm: Remove omap_dm_timer_set_load_start	2019-04-16 14:26:54 +02:00
connector	connector: fix unsafe usage of ->real_parent	2019-03-08 15:06:38 -08:00
cpufreq	cpufreq/intel_pstate: Load only on Intel hardware	2019-04-01 23:39:23 +02:00
cpuidle	cpuidle: governor: Add new governors to cpuidle_governors again	2019-03-12 23:46:55 +01:00
crypto	crypto: caam - fix copy of next buffer for xcbc and cmac	2019-03-28 13:54:32 +08:00
dax	device-dax for 5.1	2019-03-16 13:05:32 -07:00
dca	…
devfreq	…
dio	…
dma	dmaengine: stm32-mdma: Revert "dmaengine: stm32-mdma: Add a check on read_u32_array"	2019-03-25 21:56:54 +05:30
dma-buf	…
edac	Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-03-08 09:11:39 -08:00
eisa	…
extcon	extcon: ptn5150: fix COMPILE_TEST dependencies	2019-04-05 10:08:37 +09:00
firewire	…
firmware	memblock: drop memblock_alloc_*_nopanic() variants	2019-03-12 10:04:02 -07:00
fmc	…
fpga	…
fsi	…
gnss	gnss: add driver for mediatek receivers	2019-02-15 16:54:38 +01:00
gpio	gpio fixes for v5.1-rc3	2019-03-29 03:04:47 +01:00
gpu	Merge branch 'drm-fixes-5.1' of git://people.freedesktop.org/~agd5f/linux into drm-fixes	2019-04-18 06:56:35 +10:00
hid	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2019-04-19 10:28:27 -07:00
hsi	…
hv	Char/Misc driver patches for 5.1-rc1	2019-03-06 14:18:59 -08:00
hwmon	hwmon: (ntc_thermistor) Fix temperature type reporting	2019-03-29 09:51:44 -07:00
hwspinlock	…
hwtracing	ARM updates for 5.1-rc1	2019-03-15 14:37:46 -07:00
i2c	i2c: imx: don't leak the i2c adapter on error	2019-04-06 17:54:28 +02:00
i3c	i3c: dw: Fix dw_i3c_master_disable controller by using correct mask	2019-04-10 12:46:20 +02:00
ide	Revert "ide: unexport DISK_EVENT_MEDIA_CHANGE for ide-gd and ide-cd"	2019-04-12 13:35:25 -06:00
idle	intel_idle: add support for Jacobsville	2019-02-15 10:49:14 +01:00
iio	iio: core: fix a possible circular locking dependency	2019-03-31 11:11:31 +01:00
infiniband	coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping	2019-04-19 09:46:05 -07:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2019-04-19 10:28:27 -07:00
interconnect	…
iommu	iommu/amd: Set exclusion range correctly	2019-04-12 12:59:45 +02:00
ipack	…
irqchip	irqchip/irq-ls1x: Missing error code in ls1x_intc_of_init()	2019-04-05 14:37:56 +02:00
isdn	mISDN: Check address length before reading address family	2019-04-12 10:25:03 -07:00
leds	leds: trigger: netdev: use memcpy in device_name_store	2019-03-30 19:09:32 +01:00
lightnvm	lightnvm: pblk: fix crash in pblk_end_partial_read due to multipage bvecs	2019-04-10 12:17:01 -06:00
macintosh	treewide: add checks for the return value of memblock_alloc*()	2019-03-12 10:04:02 -07:00
mailbox	mailbox: imx: keep MU irq working during suspend/resume	2019-03-11 02:51:43 -05:00
mcb	…
md	bcache: Clean up bch_get_congested()	2019-04-24 10:56:27 -06:00
media	DMA mapping updates for 5.1	2019-03-10 11:54:48 -07:00
memory	…
memstick	…
message	…
mfd	mfd: sun6i-prcm: Allow to compile with COMPILE_TEST	2019-04-03 08:38:07 +01:00
misc	misc: fastrpc: add checked value for dma_set_mask	2019-04-02 17:56:54 +02:00
mmc	mmc: sdhci-omap: Don't finish_mrq() on a command error during tuning	2019-04-11 12:40:32 +02:00
mtd	mtd: cfi: fix deadloop in cfi_cmdset_0002.c do_write_buffer	2019-04-05 00:39:19 +02:00
mux	…
net	ocelot: Clean up stats update deferred work	2019-04-16 21:43:53 -07:00
nfc	…
ntb	Fixes for switchtec debugability and mapping table entries, NTB	2019-03-15 14:32:59 -07:00
nubus	…
nvdimm	Linux 5.1-rc6	2019-04-22 09:47:36 -06:00
nvme	Linux 5.1-rc6	2019-04-22 09:47:36 -06:00
nvmem	Char/Misc driver patches for 5.1-rc1	2019-03-06 14:18:59 -08:00
of	of: fix kmemleak crash caused by imbalance in early memory reservation	2019-03-12 10:04:02 -07:00
opp	PM / OPP: Update performance state when freq == old_freq	2019-03-12 09:45:56 +01:00
oprofile	…
parisc	Revert: parisc: Use F_EXTEND() macro in iosapic code	2019-04-06 19:07:55 +02:00
parport	Revert "parport: daisy: use new parport device model"	2019-03-25 14:49:00 -07:00
pci	PCI: pciehp: Ignore Link State Changes after powering off a slot	2019-04-10 16:06:43 -05:00
pcmcia	…
perf	arm64 updates for 5.1:	2019-03-10 10:17:23 -07:00
phy	phy: sun4i-usb: Support set_mode to USB_HOST for non-OTG PHYs	2019-03-26 16:48:55 +09:00
pinctrl	This is the bulk of pin control changes for the v5.1 kernel cycle.	2019-03-11 11:12:50 -07:00
platform	Here's more than a handful of clk driver fixes for changes that came in	2019-04-13 14:33:56 -07:00
pnp	ACPI/ACPICA: Trivial: fix spelling mistakes and fix whitespace formatting	2019-02-24 21:12:01 +01:00
power	drivers: power: supply: goldfish_battery: Fix bogus SPDX identifier	2019-04-15 11:16:31 +02:00
powercap	powercap/intel_rapl: add Ice Lake mobile	2019-02-18 11:31:39 +01:00
pps	…
ps3	…
ptp	Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-03-05 14:08:26 -08:00
pwm	pwm: atmel: Remove useless symbolic definitions	2019-03-04 12:52:49 +01:00
rapidio	rapidio/mport_cdev: mark expected switch fall-through	2019-03-07 18:32:02 -08:00
ras	…
regulator	regulator: mc13xxx: Constify regulator_ops variables	2019-03-04 00:01:08 +00:00
remoteproc	remoteproc updates for v5.1	2019-03-14 09:00:06 -07:00
reset	reset: meson-audio-arb: Fix missing .owner setting of reset_controller_dev	2019-03-25 16:22:10 +01:00
rpmsg	rpmsg: virtio: change header file sort style	2019-02-20 21:15:54 -08:00
rtc	rtc: da9063: set uie_unsupported when relevant	2019-04-02 23:33:09 +02:00
s390	s390 update with bug fixes for 5.1-rc6	2019-04-18 08:15:06 -07:00
sbus	…
scsi	Linux 5.1-rc6	2019-04-22 09:47:36 -06:00
sfi	…
sh	…
siox	…
slimbus	…
sn	…
soc	This pull request brings in a build fix for arm64 with bcm2835	2019-03-18 10:31:24 -07:00
soundwire	…
spi	pci-v5.1-changes	2019-03-09 14:57:08 -08:00
spmi	…
ssb	…
staging	staging: comedi: ni_usb6501: Fix possible double-free of ->usb_rx_buf	2019-04-17 11:59:24 +02:00
target	SCSI misc on 20190315	2019-03-16 12:51:50 -07:00
tc	…
tee	ARM: SoC driver updates for 5.1	2019-03-06 09:41:12 -08:00
thermal	Merge branches 'fixes' and 'thermal-intel' into next	2019-03-18 22:37:44 +08:00
thunderbolt	…
tty	sc16is7xx: put err_spi and err_i2c into correct #ifdef	2019-04-19 14:09:23 +02:00
uio	…
usb	USB-serial fixes for 5.1-rc3	2019-03-29 15:31:16 +01:00
uwb	…
vfio	vfio/type1: Limit DMA mappings per container	2019-04-03 12:43:05 -06:00
vhost	vhost: reject zero size iova range	2019-04-10 22:45:38 -07:00
video	fbdev changes for v5.1:	2019-03-15 14:22:59 -07:00
virt	virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x	2019-03-28 01:55:18 +09:00
virtio	virtio: Honour 'may_reduce_num' in vring_create_virtqueue	2019-04-08 17:05:52 -04:00
visorbus	…
vlynq	…
vme	…
w1	…
watchdog	linux-watchdog 5.1-rc1 tag	2019-03-11 11:22:15 -07:00
xen	Linux 5.1-rc6	2019-04-22 09:47:36 -06:00
zorro	…
Kconfig	…
Makefile	IOMMU Updates for Linux v5.1	2019-03-10 12:29:52 -07:00