On 12/05/2014 08:11 AM, Paul E. McKenney wrote: > On Thu, Dec 04, 2014 at 06:50:24PM -0500, Pranith Kumar wrote: >> SRCU is not necessary to be compiled by default in all cases. For >> tinification >> efforts not compiling SRCU unless necessary is desirable. >> >> The current patch tries to make compiling SRCU optional by introducing a new >> Kconfig option CONFIG_SRCU which is selected when any of the components >> making >> use of SRCU are selected. >> >> If we do not select CONFIG_SRCU, srcu.o will not be compiled at all. >> >> text data bss dec hex filename >> 2007 0 0 2007 7d7 kernel/rcu/srcu.o >> >> Size of arch/powerpc/boot/zImage changes from >> >> text data bss dec hex filename >> 831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before >> 829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after >> >> so the savings are about ~2000 bytes. >> >> Signed-off-by: Pranith Kumar <bobby.pr...@gmail.com> >> CC: Paul McKenney <paul...@linux.vnet.ibm.com> >> CC: Josh Triplett <j...@joshtriplett.org> > > I have queued this for testing. > > Josh, does this look reasonable to you? > > Lai, any issues? > > Thanx, Paul > >> --- >> arch/arm/kvm/Kconfig | 1 + >> arch/arm64/kvm/Kconfig | 1 + >> arch/ia64/kvm/Kconfig | 1 + >> arch/mips/kvm/Kconfig | 1 + >> arch/powerpc/kvm/Kconfig | 1 + >> arch/s390/kvm/Kconfig | 1 + >> arch/tile/kvm/Kconfig | 1 + >> arch/x86/Kconfig | 1 + >> arch/x86/kvm/Kconfig | 1 + >> drivers/clk/Kconfig | 1 + >> drivers/cpufreq/Kconfig | 1 + >> drivers/devfreq/Kconfig | 1 + >> drivers/md/Kconfig | 1 + >> drivers/net/Kconfig | 1 + >> fs/btrfs/Kconfig | 1 + >> fs/notify/Kconfig | 1 + >> init/Kconfig | 10 ++++++++++ >> kernel/notifier.c | 3 +++ >> kernel/rcu/Makefile | 3 ++- >> lib/Kconfig.debug | 1 + >> mm/Kconfig | 1 + >> security/tomoyo/Kconfig | 1 + >> 22 files changed, 34 insertions(+), 1 deletion(-)
Miss fs/quota/Kconfig? ./fs/quota/dquot.c:100: * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and ./fs/quota/dquot.c:1609: index = srcu_read_lock(&dquot_srcu); ./fs/quota/dquot.c:1657: index = srcu_read_lock(&dquot_srcu); ./fs/quota/dquot.c:1695: index = srcu_read_lock(&dquot_srcu); ./fs/quota/dquot.c:1724: index = srcu_read_lock(&dquot_srcu); ./fs/quota/dquot.c:1756: index = srcu_read_lock(&dquot_srcu); ./fs/quota/dquot.c:1797: index = srcu_read_lock(&dquot_srcu); ./fs/quota/dquot.c:1827: * protect them by srcu_read_lock(). And ./drivers/base/power/opp.c:90: struct srcu_notifier_head head; ./drivers/base/power/opp.c:439: srcu_init_notifier_head(&dev_opp->head); ./drivers/base/power/opp.c:484: srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp); ./drivers/base/power/opp.c:564: srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ENABLE, ./drivers/base/power/opp.c:567: srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE, ./drivers/base/power/opp.c:625:struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev) === include/linux/srcu.h and ./include/linux/notifier.h should also use "#ifdef CONFIG_SRCU .... " >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index ded8a67..1c581a0 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -137,6 +137,7 @@ config X86 >> select HAVE_ACPI_APEI_NMI if ACPI >> select ACPI_LEGACY_TABLES_LOOKUP if ACPI >> select X86_FEATURE_NAMES if PROC_FS >> + select SRCU Why you select SRCU when X86? >> >> +config SRCU >> + bool "Sleepable form of RCU" Why it has a title? Somebody need to select it manually for third party kernel module? >> + def_bool n >> + help >> + This option selects the sleepable version of RCU. This version >> + permits arbitrary sleeping or blocking within RCU read-side critical >> + sections. You used "form" and "version" at the same time. >> >> +#ifdef CONFIG_SRCU >> /* >> * SRCU notifier chain routines. Registration and unregistration >> * use a mutex, and call_chain is synchronized by SRCU (no locks). >> @@ -528,6 +529,8 @@ void srcu_init_notifier_head(struct srcu_notifier_head >> *nh) >> } >> EXPORT_SYMBOL_GPL(srcu_init_notifier_head); >> >> +#endif /* CONFIG_SRCU */ Do we need a new CONFIG_SRCU_NOTIFIER ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
