Writeback takes out a lock on the cache block, so will increase the
latency for any concurrent io.
This patch works by placing 2 sentinel objects on each level of the
multiqueues. Every WRITEBACK_PERIOD the oldest sentinel gets moved to
the newest end of the queue level.
When looking for writeback work:
if less than 25% of the cache is clean:
we select the oldest object with the lowest hit count
otherwise:
we select the oldest object that is not past a writeback sentinel.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A sentinel object is placed on each level of the multiqueues. When an
object is hit it is requeued behind the sentinel. When the tick is
incremented we iterate through all objects behind the sentinel and
update the hit_count, then reposition the sentinel at the very back.
This saves memory by avoiding tracking the tick explicitly for every
struct entry object in the multiqueues.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
queue_shift_down() didn't adjust the hit_counts to the new levels, so it
just had the effect of scrambling levels.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Small optimisation, now queue_empty() doesn't need to walk all levels of
the multiqueue.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use a single slab cache to allocate a mempool for each dirty-log.
This _should_ eliminate DM's need for io_schedule_timeout() in
mempool_alloc(); so io_schedule() should be sufficient now.
Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow
KMEM_CACHE() to create a meaningful global name for the slab cache.
Also, eliminate some holes in struct log_c by rearranging members.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n")
caused blk_stack_limits() to not properly stack queue_limits for stacked
devices (e.g. DM).
Fix this regression by establishing lcm_not_zero() and switching
blk_stack_limits() over to using it.
DM uses blk_set_stacking_limits() to establish the initial top-level
queue_limits that are then built up based on underlying devices' limits
using blk_stack_limits(). In the case of optimal_io_size (io_opt)
blk_set_stacking_limits() establishes a default value of 0. With commit
69c953c, lcm(0, n) is no longer n, which compromises proper stacking of
the underlying devices' io_opt.
Test:
$ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536
$ cat /sys/block/sde/queue/optimal_io_size
786432
$ dmsetup create node --table "0 100 linear /dev/sde 0"
Before this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
0
After this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
786432
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.19+
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
At the beginning of blk_mq_alloc_tag_set(), we have already checked whether
'set->nr_hw_queues' is zero, so here remove this redundant check.
Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull ARM SoC fixes from Olof Johansson:
"The latest and greatest fixes for ARM platform code. Worth pointing
out are:
- Lines-wise, largest is a PXA fix for dealing with interrupts on DT
that was quite broken. It's still newish code so while we could
have held this off, it seemed appropriate to include now
- Some GPIO fixes for OMAP platforms added a few lines. This was
also fixes for code recently added (this release).
- Small OMAP timer fix to behave better with partially upstreamed
platforms, which is quite welcome.
- Allwinner fixes about operating point control, reducing
overclocking in some cases for better stability.
plus a handful of other smaller fixes across the map"
* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
arm64: juno: Fix misleading name of UART reference clock
ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
ARM: socfpga: dts: fix spi1 interrupt
ARM: dts: Fix gpio interrupts for dm816x
ARM: dts: dra7: remove ti,hwmod property from pcie phy
ARM: OMAP: dmtimer: disable pm runtime on remove
ARM: OMAP: dmtimer: check for pm_runtime_get_sync() failure
ARM: OMAP2+: Fix socbus family info for AM33xx devices
ARM: dts: omap3: Add missing dmas for crypto
ARM: dts: rockchip: disable gmac by default in rk3288.dtsi
MAINTAINERS: add rockchip regexp to the ARM/Rockchip entry
ARM: pxa: fix pxa interrupts handling in DT
ARM: pxa: Fix typo in zeus.c
ARM: sunxi: Have ARCH_SUNXI select RESET_CONTROLLER for clock driver usage
Allwinner fixes for 4.0
There's a few fixes to merge for 4.0, one to add a select in the machine
Kconfig option to fix a potential build failure, and two fixing cpufreq related
issues.
* tag 'sunxi-fixes-for-4.0' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux:
ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
ARM: sunxi: Have ARCH_SUNXI select RESET_CONTROLLER for clock driver usage
Signed-off-by: Olof Johansson <olof@lixom.net>
Fixes for omaps for the -rc cycle:
- Fix a device tree based booting vs legacy booting regression for
omap3 crypto hardware by adding the missing DMA channels.
- Fix /sys/bus/soc/devices/soc0/family for am33xx devices.
- Fix two timer issues that can cause hangs if the timer related
hwmod data is missing like it often initially is for new SoCs.
- Remove pcie hwmods entry from dts as that causes runtime PM to
fail for the PHYs.
- A paper bag type dts configuration fix for dm816x GPIO
interrupts that I just noticed. This is most of the changes
diffstat wise, but as it's a basic feature for connecting
devices and things work otherwise, it should be fixed.
* tag 'fixes-v4.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: dts: Fix gpio interrupts for dm816x
ARM: dts: dra7: remove ti,hwmod property from pcie phy
ARM: OMAP: dmtimer: disable pm runtime on remove
ARM: OMAP: dmtimer: check for pm_runtime_get_sync() failure
ARM: OMAP2+: Fix socbus family info for AM33xx devices
ARM: dts: omap3: Add missing dmas for crypto
Signed-off-by: Olof Johansson <olof@lixom.net>
Late fix for v4.0 on the SoCFPGA platform:
- Fix interrupt number for SPI1 interface
* tag 'socfpga_fix_for_v4.0_2' of git://git.rocketboards.org/linux-socfpga-next:
ARM: socfpga: dts: fix spi1 interrupt
Signed-off-by: Olof Johansson <olof@lixom.net>
The UART reference clock speed is 7273.8 kHz, not 72738 kHz.
Dots aren't usually used in node names even though ePAPR permits
them. However, this can easily be avoided by expressing the
frequency in Hz, not kHz.
This patch changes the name to refclk7273800hz, reflecting the
actual clock speed.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
arm: pxa: fixes for v4.0-rc5
There are only 2 fixes, one for the zeus board about the regulator changes,
where a typo prevented the zeus board from having a working can regulator,
and one regression triggered by the interrupts IRQ shift of 16 affecting all
boards.
* tag 'fixes-for-v4.0-rc5' of https://github.com/rjarzmik/linux:
ARM: pxa: fix pxa interrupts handling in DT
ARM: pxa: Fix typo in zeus.c
Signed-off-by: Olof Johansson <olof@lixom.net>
Pull x86 fix from Ingo Molnar:
"Fix x86 syscall exit code bug that resulted in spurious non-execution
of TIF-driven user-return worklets, causing big trouble for things
like KVM that rely on user notifiers for correctness of their vcpu
model, causing crashes like double faults"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm/entry: Check for syscall exit work with IRQs disabled
Pull scheduler fix from Ingo Molnar:
"A single sched/rt corner case fix for RLIMIT_RTIME correctness"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix RLIMIT_RTTIME when PI-boosting to RT
Pull perf fix from Ingo Molnar:
"A perf kernel side fix for a fuzzer triggered lockup"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix irq_work 'tail' recursion
Pull locking fix from Ingo Molnar:
"A module unload lockdep race fix"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lockdep: Fix the module unload key range freeing logic
Pull parsic fixes from Helge Deller:
"One patch from Mikulas fixes a bug on parisc by artifically
incrementing the counter in pmd_free when the kernel tries to free
the preallocated pmd.
Other than that we now prevent that syscalls gets added without
incrementing __NR_Linux_syscalls and fix the initial pmd setup code
if a default page size greater than 4k has been selected"
* 'parisc-4.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix pmd code to depend on PT_NLEVELS value, not on CONFIG_64BIT
parisc: mm: don't count preallocated pmds
parisc: Add compile-time check when adding new syscalls
Mike Snitzer
Joe Thornber
Wei Fang
Xiaoguang Wang
Linus Torvalds
Olof Johansson
Dave Martin