Revision 58b94d88deb9ac913740e7778f2005f3ce6d0443 authored by Marcelo Ricardo Leitner on 23 December 2016, 16:29:02 UTC, committed by David S. Miller on 23 December 2016, 19:01:35 UTC
It's possible that we receive a packet that is larger than current
window. If it's the first packet in this way, it will cause it to
increase rwnd_over. Then, if we receive another data chunk (specially as
SCTP allows you to have one data chunk in flight even during 0 window),
rwnd_over will be overwritten instead of added to.

In the long run, this could cause the window to grow bigger than its
initial size, as rwnd_over would be charged only for the last received
data chunk while the code will try open the window for all packets that
were received and had its value in rwnd_over overwritten. This, then,
can lead to the worsening of payload/buffer ratio and cause rwnd_press
to kick in more often.

The fix is to sum it too, same as is done for rwnd_press, so that if we
receive 3 chunks after closing the window, we still have to release that
same amount before re-opening it.

Log snippet from sctp_test exhibiting the issue:
[  146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)
[  146.209232] sctp: sctp_assoc_rwnd_decrease:
association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1!
[  146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)
[  146.209232] sctp: sctp_assoc_rwnd_decrease:
association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1!
[  146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)
[  146.209232] sctp: sctp_assoc_rwnd_decrease:
association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1!
[  146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent e57cbe4
Raw File
Makefile
# Some of the tools (perf) use same make variables
# as in kernel build.
export srctree=
export objtree=

include scripts/Makefile.include

help:
	@echo 'Possible targets:'
	@echo ''
	@echo '  acpi                   - ACPI tools'
	@echo '  cgroup                 - cgroup tools'
	@echo '  cpupower               - a tool for all things x86 CPU power'
	@echo '  firewire               - the userspace part of nosy, an IEEE-1394 traffic sniffer'
	@echo '  freefall               - laptop accelerometer program for disk protection'
	@echo '  gpio                   - GPIO tools'
	@echo '  hv                     - tools used when in Hyper-V clients'
	@echo '  iio                    - IIO tools'
	@echo '  kvm_stat               - top-like utility for displaying kvm statistics'
	@echo '  leds                   - LEDs  tools'
	@echo '  lguest                 - a minimal 32-bit x86 hypervisor'
	@echo '  net                    - misc networking tools'
	@echo '  perf                   - Linux performance measurement and analysis tool'
	@echo '  selftests              - various kernel selftests'
	@echo '  spi                    - spi tools'
	@echo '  objtool                - an ELF object analysis tool'
	@echo '  tmon                   - thermal monitoring and tuning tool'
	@echo '  turbostat              - Intel CPU idle stats and freq reporting tool'
	@echo '  usb                    - USB testing tools'
	@echo '  virtio                 - vhost test module'
	@echo '  vm                     - misc vm tools'
	@echo '  x86_energy_perf_policy - Intel energy policy tool'
	@echo ''
	@echo 'You can do:'
	@echo ' $$ make -C tools/ <tool>_install'
	@echo ''
	@echo '  from the kernel command line to build and install one of'
	@echo '  the tools above'
	@echo ''
	@echo '  $$ make tools/all'
	@echo ''
	@echo '  builds all tools.'
	@echo ''
	@echo '  $$ make tools/install'
	@echo ''
	@echo '  installs all tools.'
	@echo ''
	@echo 'Cleaning targets:'
	@echo ''
	@echo '  all of the above with the "_clean" string appended cleans'
	@echo '    the respective build directory.'
	@echo '  clean: a summary clean target to clean _all_ folders'

acpi: FORCE
	$(call descend,power/$@)

cpupower: FORCE
	$(call descend,power/$@)

cgroup firewire hv guest spi usb virtio vm net iio gpio objtool leds: FORCE
	$(call descend,$@)

liblockdep: FORCE
	$(call descend,lib/lockdep)

libapi: FORCE
	$(call descend,lib/api)

# The perf build does not follow the descend function setup,
# invoking it via it's own make rule.
PERF_O   = $(if $(O),$(O)/tools/perf,)

perf: FORCE
	$(Q)mkdir -p $(PERF_O) .
	$(Q)$(MAKE) --no-print-directory -C perf O=$(PERF_O) subdir=

selftests: FORCE
	$(call descend,testing/$@)

turbostat x86_energy_perf_policy: FORCE
	$(call descend,power/x86/$@)

tmon: FORCE
	$(call descend,thermal/$@)

freefall: FORCE
	$(call descend,laptop/$@)

all: acpi cgroup cpupower gpio hv firewire lguest \
		perf selftests turbostat usb \
		virtio vm net x86_energy_perf_policy \
		tmon freefall objtool

acpi_install:
	$(call descend,power/$(@:_install=),install)

cpupower_install:
	$(call descend,power/$(@:_install=),install)

cgroup_install firewire_install gpio_install hv_install lguest_install perf_install usb_install virtio_install vm_install net_install objtool_install:
	$(call descend,$(@:_install=),install)

selftests_install:
	$(call descend,testing/$(@:_install=),install)

turbostat_install x86_energy_perf_policy_install:
	$(call descend,power/x86/$(@:_install=),install)

tmon_install:
	$(call descend,thermal/$(@:_install=),install)

freefall_install:
	$(call descend,laptop/$(@:_install=),install)

kvm_stat_install:
	$(call descend,kvm/$(@:_install=),install)

install: acpi_install cgroup_install cpupower_install gpio_install \
		hv_install firewire_install lguest_install \
		perf_install selftests_install turbostat_install usb_install \
		virtio_install vm_install net_install x86_energy_perf_policy_install \
		tmon_install freefall_install objtool_install kvm_stat_install

acpi_clean:
	$(call descend,power/acpi,clean)

cpupower_clean:
	$(call descend,power/cpupower,clean)

cgroup_clean hv_clean firewire_clean lguest_clean spi_clean usb_clean virtio_clean vm_clean net_clean iio_clean gpio_clean objtool_clean leds_clean:
	$(call descend,$(@:_clean=),clean)

liblockdep_clean:
	$(call descend,lib/lockdep,clean)

libapi_clean:
	$(call descend,lib/api,clean)

libbpf_clean:
	$(call descend,lib/bpf,clean)

libsubcmd_clean:
	$(call descend,lib/subcmd,clean)

perf_clean:
	$(Q)mkdir -p $(PERF_O) .
	$(Q)$(MAKE) --no-print-directory -C perf O=$(PERF_O) subdir= clean

selftests_clean:
	$(call descend,testing/$(@:_clean=),clean)

turbostat_clean x86_energy_perf_policy_clean:
	$(call descend,power/x86/$(@:_clean=),clean)

tmon_clean:
	$(call descend,thermal/tmon,clean)

freefall_clean:
	$(call descend,laptop/freefall,clean)

build_clean:
	$(call descend,build,clean)

clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean lguest_clean \
		perf_clean selftests_clean turbostat_clean spi_clean usb_clean virtio_clean \
		vm_clean net_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
		freefall_clean build_clean libbpf_clean libsubcmd_clean liblockdep_clean \
		gpio_clean objtool_clean leds_clean

.PHONY: FORCE
back to top