DCTCP congestion control algorithm aims to maximise throughput and minimise
latency in data center networks by utilising the proportion of Explicit
Congestion Notification (ECN) marked packets received from capable hardware as a
congestion signal.
Highlights:
Implemented as a mod_cc(4) module.
ECN (Explicit congestion notification) processing is done differently from
RFC3168.
Takes one-sided DCTCP into consideration where only one of the sides is using
DCTCP and other is using standard ECN.
IETF draft: http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00
Thesis report by Midori Kato: https://eggert.org/students/kato-thesis.pdf
Submitted by: Midori Kato <katoon@sfc.wide.ad.jp> and
Lars Eggert <lars@netapp.com>
with help and modifications from
hiren
Differential Revision: https://reviews.freebsd.org/D604
Reviewed by: gnn
For /dev/mem, when requested physical address is not accessible by the
direct map, do temporal remaping with the caching attribute
'uncached'. Limit the accessible addresses by MAXPHYADDR, since the
architecture disallowes writing non-zero into reserved bits of ptes
(or setting garbage into NX).
For /dev/kmem, only access existing kernel mappings for direct map
region. For all other addresses, obtain a physical address of the
mapping and fall back to the /dev/mem mechanism. This ensures that
/dev/kmem i/o does not fault even if the accessed region is changed in
parallel, by using either direct map or temporal mapping.
For both devices, operate on one page by iteration. Do not return
error if any bytes were moved around, return the (partial) bytes count
to userspace.
Reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
unnecessary filter configuration code in nge_init_locked().
While I'm here add a check for driver running state for multicast
filter handling. Also remove unnecessary assignment to error
variable since it is cleared in the function entry.
Suggested by: brad@OpenBSD.org
Features by CPUID as CPUID.80000008H:EAX[7:0], into variable cpu_maxphyaddr.
Reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
devices which don't support the synchronize cache SCSI command are
likely to also not support the prevent-allow medium removal SCSI
command.
PR: 185747
MFC after: 1 week
To cut off the power we need to start the shutdown sequence by writing
the OFF bit on PMIC.
Once the PMIC is programmed the SoC needs to toggle the PMIC_PWR_ENABLE
pin when it is ready for the PMIC to cut off the power. This is done by
triggering the ALARM2 interrupt on SoC RTC.
The RTC driver only works in power management mode which means it won't
provide any kind of time keeping functionality. It only implements a way
to trigger the ALARM2 interrupt when requested.
Differential Revision: https://reviews.freebsd.org/D1489
Reviewed by: rpaulo
MFC after: 2 weeks
Most recent import in r276398 and switch to ELF Tool Chain tools by
default in r276796.
Reviewed by: gjb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1501
The driver inherently does dma in 512 byte chunks, but it's possible that
such a buffer can span two physically discontiguous pages (such as when
a userland program does IO on the raw /dev/mmcsdN devices). Now the driver
can handle a buffer that's split across two pages.
It could in theory handle any number of segments now, but as long as IO is
being done in 512 byte blocks it will never need more than two.
cancellation-handling code in the libthr. Translate some syscalls
into their more generic counterpart, and remove translated syscalls
from the table.
List of the affected syscalls:
creat, open -> openat
raise -> thr_kill
sleep, usleep -> nanosleep
pause -> sigsuspend
wait, wait3, waitpid -> wait4
Suggested and reviewed by: jilles (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
requires that each 512 byte IO be in a single contiguous buffer, but if a
buffer crosses a page boundary and the physical pages aren't contiguous
you can get an EFBIG failure (too many segments).
The driver really should handle multiple segment IO, but before adding that
I wanted to make sure that it's handling failure properly while the failure
is easily recreatable.
moving the handling of curcmd->error != 0 to the end of the interrupt
handler. Also make sdhci_finish_data() idempotent by moving the setting
of slot->data_done = 1 down past the point where the busdma buffer is
unmapped. This allows for the possibility that the finish routine can
get called from multiple places when handling errors.
cache for whole page containing modified pte, and more, only last page
in the series of the consequtive pages is flushed (i.e. the affected
mappings should be larger than 2MB).
Avoid excessive flushing and do missed neccessary flushing, by
splitting invalidation and unmapping. For now, flush exactly the
range of the changed pte. This is still somewhat bigger than
neccessary, since pte is 8 bytes, while cache flush line is at least
32 bytes.
The originator of the issue reports that after the change,
'dmar_bus_dmamap_unload went from 13,288 cycles down to
3,257. dmar_bus_dmamap_load_buffer went from 9,686 cycles down to
3,517. and I am now able to get line 1GbE speed with Netperf TCP
(even with 1K message size).'
Diagnosed and tested by: Nadav Amit <nadav.amit@gmail.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
