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
Raw File
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()
Tip revision: 40fea92
Makefile.lib
# Backward compatibility
asflags-y  += $(EXTRA_AFLAGS)
ccflags-y  += $(EXTRA_CFLAGS)
cppflags-y += $(EXTRA_CPPFLAGS)
ldflags-y  += $(EXTRA_LDFLAGS)

#
# flags that take effect in sub directories
export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)
export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)

# Figure out what we need to build from the various variables
# ===========================================================================

# When an object is listed to be built compiled-in and modular,
# only build the compiled-in version

obj-m := $(filter-out $(obj-y),$(obj-m))

# Libraries are always collected in one lib file.
# Filter out objects already built-in

lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))


# Handle objects in subdirs
# ---------------------------------------------------------------------------
# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o
#   and add the directory to the list of dirs to descend into: $(subdir-y)
# o if we encounter foo/ in $(obj-m), remove it from $(obj-m) 
#   and add the directory to the list of dirs to descend into: $(subdir-m)

# Determine modorder.
# Unfortunately, we don't have information about ordering between -y
# and -m subdirs.  Just put -y's first.
modorder	:= $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))

__subdir-y	:= $(patsubst %/,%,$(filter %/, $(obj-y)))
subdir-y	+= $(__subdir-y)
__subdir-m	:= $(patsubst %/,%,$(filter %/, $(obj-m)))
subdir-m	+= $(__subdir-m)
obj-y		:= $(patsubst %/, %/built-in.o, $(obj-y))
obj-m		:= $(filter-out %/, $(obj-m))

# Subdirectories we need to descend into

subdir-ym	:= $(sort $(subdir-y) $(subdir-m))

# if $(foo-objs) exists, foo.o is a composite object 
multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
multi-used   := $(multi-used-y) $(multi-used-m)
single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m)))

# Build list of the parts of our composite objects, our composite
# objects depend on those (obviously)
multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))
multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
multi-objs   := $(multi-objs-y) $(multi-objs-m)

# $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
# tell kbuild to descend
subdir-obj-y := $(filter %/built-in.o, $(obj-y))

# $(obj-dirs) is a list of directories that contain object files
obj-dirs := $(dir $(multi-objs) $(obj-y))

# Replace multi-part objects by their individual parts, look at local dir only
real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y)
real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))

# Add subdir path

extra-y		:= $(addprefix $(obj)/,$(extra-y))
always		:= $(addprefix $(obj)/,$(always))
targets		:= $(addprefix $(obj)/,$(targets))
modorder	:= $(addprefix $(obj)/,$(modorder))
obj-y		:= $(addprefix $(obj)/,$(obj-y))
obj-m		:= $(addprefix $(obj)/,$(obj-m))
lib-y		:= $(addprefix $(obj)/,$(lib-y))
subdir-obj-y	:= $(addprefix $(obj)/,$(subdir-obj-y))
real-objs-y	:= $(addprefix $(obj)/,$(real-objs-y))
real-objs-m	:= $(addprefix $(obj)/,$(real-objs-m))
single-used-m	:= $(addprefix $(obj)/,$(single-used-m))
multi-used-y	:= $(addprefix $(obj)/,$(multi-used-y))
multi-used-m	:= $(addprefix $(obj)/,$(multi-used-m))
multi-objs-y	:= $(addprefix $(obj)/,$(multi-objs-y))
multi-objs-m	:= $(addprefix $(obj)/,$(multi-objs-m))
subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))
obj-dirs	:= $(addprefix $(obj)/,$(obj-dirs))

# These flags are needed for modversions and compiling, so we define them here
# already
# $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will 
# end up in (or would, if it gets compiled in)
# Note: Files that end up in two or more modules are compiled without the
#       KBUILD_MODNAME definition. The reason is that any made-up name would
#       differ in different configs.
name-fix = $(subst $(comma),_,$(subst -,_,$1))
basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))"
modname_flags  = $(if $(filter 1,$(words $(modname))),\
                 -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")

orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
                 $(ccflags-y) $(CFLAGS_$(basetarget).o)
_c_flags       = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
_a_flags       = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
                 $(asflags-y) $(AFLAGS_$(basetarget).o)
_cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))

#
# Enable gcov profiling flags for a file, directory or for all files depending
# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
# (in this order)
#
ifeq ($(CONFIG_GCOV_KERNEL),y)
_c_flags += $(if $(patsubst n%,, \
		$(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
		$(CFLAGS_GCOV))
endif

# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').

ifeq ($(KBUILD_SRC),)
__c_flags	= $(_c_flags)
__a_flags	= $(_a_flags)
__cpp_flags     = $(_cpp_flags)
else

# -I$(obj) locates generated .h files
# $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
#   and locates generated .h files
# FIXME: Replace both with specific CFLAGS* statements in the makefiles
__c_flags	= $(call addtree,-I$(obj)) $(call flags,_c_flags)
__a_flags	=                          $(call flags,_a_flags)
__cpp_flags     =                          $(call flags,_cpp_flags)
endif

c_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
		 $(__c_flags) $(modkern_cflags)                           \
		 -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags)

a_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
		 $(__a_flags) $(modkern_aflags)

cpp_flags      = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
		 $(__cpp_flags)

ld_flags       = $(LDFLAGS) $(ldflags-y)

dtc_cpp_flags  = -Wp,-MD,$(depfile).pre.tmp -nostdinc                    \
		 -I$(srctree)/arch/$(SRCARCH)/boot/dts                   \
		 -I$(srctree)/arch/$(SRCARCH)/boot/dts/include           \
		 -undef -D__DTS__

# Finds the multi-part object the current object will be linked into
modname-multi = $(sort $(foreach m,$(multi-used),\
		$(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=))))

ifdef REGENERATE_PARSERS

# GPERF
# ---------------------------------------------------------------------------
quiet_cmd_gperf = GPERF $@
      cmd_gperf = gperf -t --output-file $@ -a -C -E -g -k 1,3,$$ -p -t $<

.PRECIOUS: $(src)/%.hash.c_shipped
$(src)/%.hash.c_shipped: $(src)/%.gperf
	$(call cmd,gperf)

# LEX
# ---------------------------------------------------------------------------
LEX_PREFIX = $(if $(LEX_PREFIX_${baseprereq}),$(LEX_PREFIX_${baseprereq}),yy)

quiet_cmd_flex = LEX     $@
      cmd_flex = flex -o$@ -L -P $(LEX_PREFIX) $<

.PRECIOUS: $(src)/%.lex.c_shipped
$(src)/%.lex.c_shipped: $(src)/%.l
	$(call cmd,flex)

# YACC
# ---------------------------------------------------------------------------
YACC_PREFIX = $(if $(YACC_PREFIX_${baseprereq}),$(YACC_PREFIX_${baseprereq}),yy)

quiet_cmd_bison = YACC    $@
      cmd_bison = bison -o$@ -t -l -p $(YACC_PREFIX) $<

.PRECIOUS: $(src)/%.tab.c_shipped
$(src)/%.tab.c_shipped: $(src)/%.y
	$(call cmd,bison)

quiet_cmd_bison_h = YACC    $@
      cmd_bison_h = bison -o/dev/null --defines=$@ -t -l -p $(YACC_PREFIX) $<

.PRECIOUS: $(src)/%.tab.h_shipped
$(src)/%.tab.h_shipped: $(src)/%.y
	$(call cmd,bison_h)

endif

# Shipped files
# ===========================================================================

quiet_cmd_shipped = SHIPPED $@
cmd_shipped = cat $< > $@

$(obj)/%: $(src)/%_shipped
	$(call cmd,shipped)

# Commands useful for building a boot image
# ===========================================================================
# 
#	Use as following:
#
#	target: source(s) FORCE
#		$(if_changed,ld/objcopy/gzip)
#
#	and add target to extra-y so that we know we have to
#	read in the saved command line

# Linking
# ---------------------------------------------------------------------------

quiet_cmd_ld = LD      $@
cmd_ld = $(LD) $(LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) \
	       $(filter-out FORCE,$^) -o $@ 

# Objcopy
# ---------------------------------------------------------------------------

quiet_cmd_objcopy = OBJCOPY $@
cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@

# Gzip
# ---------------------------------------------------------------------------

quiet_cmd_gzip = GZIP    $@
cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
	(rm -f $@ ; false)

# DTC
# ---------------------------------------------------------------------------

# Generate an assembly file to wrap the output of the device tree compiler
quiet_cmd_dt_S_dtb= DTB     $@
cmd_dt_S_dtb=						\
(							\
	echo '\#include <asm-generic/vmlinux.lds.h>'; 	\
	echo '.section .dtb.init.rodata,"a"';		\
	echo '.balign STRUCT_ALIGNMENT';		\
	echo '.global __dtb_$(*F)_begin';		\
	echo '__dtb_$(*F)_begin:';			\
	echo '.incbin "$<" ';				\
	echo '__dtb_$(*F)_end:';			\
	echo '.global __dtb_$(*F)_end';			\
	echo '.balign STRUCT_ALIGNMENT'; 		\
) > $@

$(obj)/%.dtb.S: $(obj)/%.dtb
	$(call cmd,dt_S_dtb)

quiet_cmd_dtc = DTC     $@
cmd_dtc = $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
	$(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 \
		-i $(dir $<) $(DTC_FLAGS) \
		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)

$(obj)/%.dtb: $(src)/%.dts FORCE
	$(call if_changed_dep,dtc)

dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)

# Bzip2
# ---------------------------------------------------------------------------

# Bzip2 and LZMA do not include size in file... so we have to fake that;
# append the size as a 32-bit littleendian number as gzip does.
size_append = printf $(shell						\
dec_size=0;								\
for F in $1; do								\
	fsize=$$(stat -c "%s" $$F);					\
	dec_size=$$(expr $$dec_size + $$fsize);				\
done;									\
printf "%08x\n" $$dec_size |						\
	sed 's/\(..\)/\1 /g' | {					\
		read ch0 ch1 ch2 ch3;					\
		for ch in $$ch3 $$ch2 $$ch1 $$ch0; do			\
			printf '%s%03o' '\\' $$((0x$$ch)); 		\
		done;							\
	}								\
)

quiet_cmd_bzip2 = BZIP2   $@
cmd_bzip2 = (cat $(filter-out FORCE,$^) | \
	bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
	(rm -f $@ ; false)

# Lzma
# ---------------------------------------------------------------------------

quiet_cmd_lzma = LZMA    $@
cmd_lzma = (cat $(filter-out FORCE,$^) | \
	lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
	(rm -f $@ ; false)

quiet_cmd_lzo = LZO     $@
cmd_lzo = (cat $(filter-out FORCE,$^) | \
	lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
	(rm -f $@ ; false)

quiet_cmd_lz4 = LZ4     $@
cmd_lz4 = (cat $(filter-out FORCE,$^) | \
	lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
	(rm -f $@ ; false)

# U-Boot mkimage
# ---------------------------------------------------------------------------

MKIMAGE := $(srctree)/scripts/mkuboot.sh

# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
# the number of overrides in arch makefiles
UIMAGE_ARCH ?= $(SRCARCH)
UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
UIMAGE_OPTS-y ?=
UIMAGE_TYPE ?= kernel
UIMAGE_LOADADDR ?= arch_must_set_this
UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
UIMAGE_IN ?= $<
UIMAGE_OUT ?= $@

quiet_cmd_uimage = UIMAGE  $(UIMAGE_OUT)
      cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
			-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
			-T $(UIMAGE_TYPE) \
			-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
			-n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT)

# XZ
# ---------------------------------------------------------------------------
# Use xzkern to compress the kernel image and xzmisc to compress other things.
#
# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
# of the kernel decompressor. A BCJ filter is used if it is available for
# the target architecture. xzkern also appends uncompressed size of the data
# using size_append. The .xz format has the size information available at
# the end of the file too, but it's in more complex format and it's good to
# avoid changing the part of the boot code that reads the uncompressed size.
# Note that the bytes added by size_append will make the xz tool think that
# the file is corrupt. This is expected.
#
# xzmisc doesn't use size_append, so it can be used to create normal .xz
# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
# big dictionary would increase the memory usage too much in the multi-call
# decompression mode. A BCJ filter isn't used either.
quiet_cmd_xzkern = XZKERN  $@
cmd_xzkern = (cat $(filter-out FORCE,$^) | \
	sh $(srctree)/scripts/xz_wrap.sh && \
	$(call size_append, $(filter-out FORCE,$^))) > $@ || \
	(rm -f $@ ; false)

quiet_cmd_xzmisc = XZMISC  $@
cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
	xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
	(rm -f $@ ; false)

# misc stuff
# ---------------------------------------------------------------------------
quote:="
back to top