https://github.com/torvalds/linux
Revision 40fea92ffb5fa0ef26d10ae0fe5688bc8e61c791 authored by Stephen Boyd on 13 August 2013, 21:12:40 UTC, committed by Rafael J. Wysocki on 13 August 2013, 22:42:05 UTC
pm_qos_update_request_timeout() updates a qos and then schedules a delayed work item to bring the qos back down to the default after the timeout. When the work item runs, pm_qos_work_fn() will call pm_qos_update_request() and deadlock because it tries to cancel itself via cancel_delayed_work_sync(). Future callers of that qos will also hang waiting to cancel the work that is canceling itself. Let's extract the little bit of code that does the real work of pm_qos_update_request() and call it from the work function so that we don't deadlock. Before ed1ac6e (PM: don't use [delayed_]work_pending()) this didn't happen because the work function wouldn't try to cancel itself. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: 3.9+ <stable@vger.kernel.org> # 3.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 parent d4e4ab8
Tip revision: 40fea92ffb5fa0ef26d10ae0fe5688bc8e61c791 authored by Stephen Boyd on 13 August 2013, 21:12:40 UTC
PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()
PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()
Tip revision: 40fea92
Makefile.headersinst
# ==========================================================================
# Installing headers
#
# header-y - list files to be installed. They are preprocessed
# to remove __KERNEL__ section of the file
# genhdr-y - Same as header-y but in a generated/ directory
#
# ==========================================================================
# generated header directory
gen := $(if $(gen),$(gen),$(subst include/,include/generated/,$(obj)))
kbuild-file := $(srctree)/$(obj)/Kbuild
include $(kbuild-file)
# called may set destination dir (when installing to asm/)
_dst := $(if $(destination-y),$(destination-y),$(if $(dst),$(dst),$(obj)))
old-kbuild-file := $(srctree)/$(subst uapi/,,$(obj))/Kbuild
ifneq ($(wildcard $(old-kbuild-file)),)
include $(old-kbuild-file)
endif
include scripts/Kbuild.include
installdir := $(INSTALL_HDR_PATH)/$(subst uapi/,,$(_dst))
header-y := $(sort $(header-y))
subdirs := $(patsubst %/,%,$(filter %/, $(header-y)))
header-y := $(filter-out %/, $(header-y))
# files used to track state of install/check
install-file := $(installdir)/.install
check-file := $(installdir)/.check
# generic-y list all files an architecture uses from asm-generic
# Use this to build a list of headers which require a wrapper
wrapper-files := $(filter $(header-y), $(generic-y))
srcdir := $(srctree)/$(obj)
gendir := $(objtree)/$(gen)
oldsrcdir := $(srctree)/$(subst /uapi,,$(obj))
# all headers files for this dir
header-y := $(filter-out $(generic-y), $(header-y))
all-files := $(header-y) $(genhdr-y) $(wrapper-files)
output-files := $(addprefix $(installdir)/, $(all-files))
input-files1 := $(foreach hdr, $(header-y), \
$(if $(wildcard $(srcdir)/$(hdr)), \
$(wildcard $(srcdir)/$(hdr))) \
)
input-files1-name := $(notdir $(input-files1))
input-files2 := $(foreach hdr, $(header-y), \
$(if $(wildcard $(srcdir)/$(hdr)),, \
$(if $(wildcard $(oldsrcdir)/$(hdr)), \
$(wildcard $(oldsrcdir)/$(hdr)), \
$(error Missing UAPI file $(srcdir)/$(hdr))) \
))
input-files2-name := $(notdir $(input-files2))
input-files3 := $(foreach hdr, $(genhdr-y), \
$(if $(wildcard $(gendir)/$(hdr)), \
$(wildcard $(gendir)/$(hdr)), \
$(error Missing generated UAPI file $(gendir)/$(hdr)) \
))
input-files3-name := $(notdir $(input-files3))
# Work out what needs to be removed
oldheaders := $(patsubst $(installdir)/%,%,$(wildcard $(installdir)/*.h))
unwanted := $(filter-out $(all-files),$(oldheaders))
# Prefix unwanted with full paths to $(INSTALL_HDR_PATH)
unwanted-file := $(addprefix $(installdir)/, $(unwanted))
printdir = $(patsubst $(INSTALL_HDR_PATH)/%/,%,$(dir $@))
quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
file$(if $(word 2, $(all-files)),s))
cmd_install = \
$(CONFIG_SHELL) $< $(installdir) $(srcdir) $(input-files1-name); \
$(CONFIG_SHELL) $< $(installdir) $(oldsrcdir) $(input-files2-name); \
$(CONFIG_SHELL) $< $(installdir) $(gendir) $(input-files3-name); \
for F in $(wrapper-files); do \
echo "\#include <asm-generic/$$F>" > $(installdir)/$$F; \
done; \
touch $@
quiet_cmd_remove = REMOVE $(unwanted)
cmd_remove = rm -f $(unwanted-file)
quiet_cmd_check = CHECK $(printdir) ($(words $(all-files)) files)
# Headers list can be pretty long, xargs helps to avoid
# the "Argument list too long" error.
cmd_check = for f in $(all-files); do \
echo "$(installdir)/$${f}"; done \
| xargs \
$(PERL) $< $(INSTALL_HDR_PATH)/include $(SRCARCH); \
touch $@
PHONY += __headersinst __headerscheck
ifndef HDRCHECK
# Rules for installing headers
__headersinst: $(subdirs) $(install-file)
@:
targets += $(install-file)
$(install-file): scripts/headers_install.sh $(input-files1) $(input-files2) $(input-files3) FORCE
$(if $(unwanted),$(call cmd,remove),)
$(if $(wildcard $(dir $@)),,$(shell mkdir -p $(dir $@)))
$(call if_changed,install)
else
__headerscheck: $(subdirs) $(check-file)
@:
targets += $(check-file)
$(check-file): scripts/headers_check.pl $(output-files) FORCE
$(call if_changed,check)
endif
# Recursion
hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
.PHONY: $(subdirs)
$(subdirs):
$(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(_dst)/$@
targets := $(wildcard $(sort $(targets)))
cmd_files := $(wildcard \
$(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
ifneq ($(cmd_files),)
include $(cmd_files)
endif
.PHONY: $(PHONY)
PHONY += FORCE
FORCE: ;
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