* [pull request] getting rid of __cpuinit
@ 2008-10-24 21:20 Arjan van de Ven
2008-10-24 21:37 ` [PATCH] kbuild: drop cpuinit/cpuexit checks in modpost Sam Ravnborg
2008-10-25 7:59 ` [pull request] getting rid of __cpuinit Sam Ravnborg
0 siblings, 2 replies; 11+ messages in thread
From: Arjan van de Ven @ 2008-10-24 21:20 UTC (permalink / raw)
To: torvalds; +Cc: linux-kernel, Matt Mackall
Hi Linus,
this is one of those pull requests for which the best timing is likely at the
end of the merge window due to touching a large number of files in a trivial way.
In fact, 6 of the 8 patches were done via regexps:
find -name "*.c" | xargs sed -i "s/^__cpuinit //g"
find arch/ -name "*.h" | xargs sed -i "s/ __cpuinit//g"
find -name "*.c" | xargs sed -i "s/ __cpuinit$//g"
find -name "*.c" | xargs sed -i "s/ __cpuinitdata//g"
find -name "*.c" | xargs sed -i "s/ __cpuexit / /g"
find -name "*.c" | xargs sed -i "s/ __cpuinit / /g"
(I suppose asking for a "git sed" is too much to do...)
The point of this series is to get rid of __cpuinit. (I'll be working on other __XXXXinit after this)
__cpuinit is a NOOP for CONFIG_HOTPLUG_CPU, which on for just about anybody in practice
(in fact I had to disable 6 common options to even be ABLE to turn it off for size testing)
and all distros also ship with it enabled.
Yet it's a rather error prone construct since the rules of this sort of __XXXXinit thing are
rather complex and convoluted.. better to just get rid of it entirely.
As for the code size effect, after I spent a bunch of time cursing and trying to find out
how to disable HOTPLUG_CPU, I managed to get an x86-64 build that actually shows how much space
we ACTUALLY save with all the __cpuinit's in the tree... it's less than 2Kb. That is, if you manage
to turn it actually off.
text data bss dec hex filename
4618096 1358684 848588 6825368 682598 vmlinux.before
4619965 1356908 848716 6825589 682675 vmlinux.after
Please consider pulling; or if you think another time is more appropriate just let me know;
re-running the regexps isn't all that much work.
Note: the patch leaves the __cpuinit macro still existent so that in-flight code that might
use it won't immediately break, but over time I want to kill that as well. (just not right now,
because it could break various people's workflow and a few empty defines don't hurt all that much)
The following changes since commit e013e13bf605b9e6b702adffbe2853cfc60e7806:
Jens Axboe (1):
libata: fix bug with non-ncq devices
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-init.git ..BRANCH.NOT.VERIFIED..
Arjan van de Ven (8):
cpuinit: get rid of __cpuinit, first regexp
cpuinit: get rid of __cpuinit, second regexp
cpuinit: get rid of __cpuinit, third regexp
cpuinit: get rid of __cpuinit, fourth regexp
cpuinit: get rid of __cpuinit, fifth regexp
cpuinit: get rid of __cpuinit, sixth regexp
cpuinit: get rid of __cpuinit, manual fixups
cpuinit: turn __cpuinit into nops
Documentation/cpu-hotplug.txt | 4 +-
arch/alpha/kernel/smp.c | 4 +-
arch/arm/common/gic.c | 2 +-
arch/arm/kernel/smp.c | 12 ++--
arch/arm/mach-realview/localtimer.c | 8 ++--
arch/arm/mach-realview/platsmp.c | 6 +-
arch/cris/arch-v32/kernel/smp.c | 2 +-
arch/frv/kernel/setup.c | 2 +-
arch/ia64/kernel/err_inject.c | 8 ++--
arch/ia64/kernel/mca.c | 12 ++--
arch/ia64/kernel/numa.c | 4 +-
arch/ia64/kernel/palinfo.c | 4 +-
arch/ia64/kernel/salinfo.c | 4 +-
arch/ia64/kernel/setup.c | 10 ++--
arch/ia64/kernel/smpboot.c | 12 ++--
arch/ia64/kernel/topology.c | 18 ++++----
arch/ia64/mm/contig.c | 2 +-
arch/ia64/mm/discontig.c | 2 +-
arch/ia64/sn/kernel/setup.c | 4 +-
arch/ia64/xen/hypervisor.c | 2 +-
arch/m32r/kernel/smpboot.c | 2 +-
arch/mips/kernel/cevt-bcm1480.c | 2 +-
arch/mips/kernel/cevt-r4k.c | 2 +-
arch/mips/kernel/cevt-sb1250.c | 2 +-
arch/mips/kernel/cevt-smtc.c | 2 +-
arch/mips/kernel/cpu-bugs64.c | 4 +-
arch/mips/kernel/cpu-probe.c | 10 ++--
arch/mips/kernel/smp-mt.c | 6 +-
arch/mips/kernel/smp-up.c | 6 +-
arch/mips/kernel/smp.c | 6 +-
arch/mips/kernel/smtc.c | 2 +-
arch/mips/kernel/spram.c | 14 +++---
arch/mips/kernel/time.c | 2 +-
arch/mips/kernel/traps.c | 8 ++--
arch/mips/kernel/watch.c | 2 +-
arch/mips/lib/uncached.c | 2 +-
arch/mips/mipssim/sim_smtc.c | 6 +-
arch/mips/mipssim/sim_time.c | 2 +-
arch/mips/mm/c-r3k.c | 8 ++--
arch/mips/mm/c-r4k.c | 34 +++++++-------
arch/mips/mm/c-tx39.c | 2 +-
arch/mips/mm/page.c | 40 ++++++++--------
arch/mips/mm/sc-ip22.c | 2 +-
arch/mips/mm/sc-mips.c | 2 +-
arch/mips/mm/sc-r5k.c | 2 +-
arch/mips/mm/sc-rm7k.c | 6 +-
arch/mips/mm/tlb-r3k.c | 2 +-
arch/mips/mm/tlb-r4k.c | 8 ++--
arch/mips/mm/tlb-r8k.c | 4 +-
arch/mips/mm/tlbex.c | 70 ++++++++++++++--------------
arch/mips/mm/uasm.c | 70 ++++++++++++++--------------
arch/mips/mm/uasm.h | 24 +++++-----
arch/mips/mti-malta/malta-smtc.c | 6 +-
arch/mips/mti-malta/malta-time.c | 2 +-
arch/mips/pci/pci-ip27.c | 2 +-
arch/mips/pmc-sierra/yosemite/smp.c | 12 ++--
arch/mips/sgi-ip27/ip27-init.c | 4 +-
arch/mips/sgi-ip27/ip27-smp.c | 6 +-
arch/mips/sgi-ip27/ip27-timer.c | 6 +-
arch/mips/sgi-ip27/ip27-xtalk.c | 6 +-
arch/mips/sibyte/bcm1480/smp.c | 8 ++--
arch/mips/sibyte/sb1250/smp.c | 8 ++--
arch/parisc/kernel/hardware.c | 2 +-
arch/parisc/kernel/processor.c | 2 +-
arch/parisc/kernel/smp.c | 4 +-
arch/powerpc/kernel/smp.c | 2 +-
arch/powerpc/kernel/sysfs.c | 12 ++--
arch/powerpc/mm/numa.c | 12 ++--
arch/s390/appldata/appldata_base.c | 8 ++--
arch/s390/kernel/entry.h | 2 +-
arch/s390/kernel/setup.c | 4 +-
arch/s390/kernel/smp.c | 10 ++--
arch/sh/kernel/setup.c | 2 +-
arch/sh/kernel/smp.c | 4 +-
arch/sh/kernel/timers/timer-broadcast.c | 2 +-
arch/sh/kernel/traps_32.c | 2 +-
arch/sparc/kernel/smp.c | 8 ++--
arch/sparc/kernel/sun4d_smp.c | 2 +-
arch/sparc/kernel/sun4m_smp.c | 4 +-
arch/sparc64/kernel/ds.c | 4 +-
arch/sparc64/kernel/entry.h | 2 +-
arch/sparc64/kernel/irq.c | 4 +-
arch/sparc64/kernel/mdesc.c | 2 +-
arch/sparc64/kernel/smp.c | 4 +-
arch/sparc64/kernel/sysfs.c | 4 +-
arch/sparc64/mm/init.c | 2 +-
arch/x86/include/asm/ds.h | 2 +-
arch/x86/include/asm/mmconfig.h | 4 +-
arch/x86/include/asm/mpspec.h | 2 +-
arch/x86/include/asm/numa_64.h | 8 ++--
arch/x86/include/asm/ptrace.h | 2 +-
arch/x86/include/asm/smp.h | 4 +-
arch/x86/kernel/acpi/boot.c | 4 +-
arch/x86/kernel/apic.c | 20 ++++----
arch/x86/kernel/cpu/addon_cpuid_features.c | 6 +-
arch/x86/kernel/cpu/amd.c | 22 ++++----
arch/x86/kernel/cpu/centaur.c | 26 +++++-----
arch/x86/kernel/cpu/centaur_64.c | 6 +-
arch/x86/kernel/cpu/common.c | 58 +++++++++++-----------
arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 4 +-
arch/x86/kernel/cpu/cyrix.c | 40 ++++++++--------
arch/x86/kernel/cpu/intel.c | 22 ++++----
arch/x86/kernel/cpu/intel_cacheinfo.c | 44 +++++++++---------
arch/x86/kernel/cpu/mcheck/mce_64.c | 16 +++---
arch/x86/kernel/cpu/mcheck/mce_amd_64.c | 10 ++--
arch/x86/kernel/cpu/mcheck/mce_intel_64.c | 4 +-
arch/x86/kernel/cpu/mcheck/therm_throt.c | 8 ++--
arch/x86/kernel/cpu/transmeta.c | 6 +-
arch/x86/kernel/cpu/umc.c | 2 +-
arch/x86/kernel/cpuid.c | 4 +-
arch/x86/kernel/ds.c | 2 +-
arch/x86/kernel/genx2apic_uv_x.c | 4 +-
arch/x86/kernel/i387.c | 6 +-
arch/x86/kernel/irq_32.c | 2 +-
arch/x86/kernel/microcode_core.c | 2 +-
arch/x86/kernel/mmconf-fam10h_64.c | 14 +++---
arch/x86/kernel/msr.c | 4 +-
arch/x86/kernel/numaq_32.c | 4 +-
arch/x86/kernel/process.c | 8 ++--
arch/x86/kernel/ptrace.c | 2 +-
arch/x86/kernel/setup.c | 2 +-
arch/x86/kernel/setup_percpu.c | 16 +++---
arch/x86/kernel/smpboot.c | 28 ++++++------
arch/x86/kernel/smpcommon.c | 2 +-
arch/x86/kernel/tlb_64.c | 2 +-
arch/x86/kernel/tsc.c | 2 +-
arch/x86/kernel/tsc_sync.c | 18 ++++----
arch/x86/kernel/vsyscall_64.c | 6 +-
arch/x86/kernel/xsave.c | 2 +-
arch/x86/mach-voyager/voyager_smp.c | 4 +-
arch/x86/mm/init_64.c | 4 +-
arch/x86/mm/numa_64.c | 2 +-
arch/x86/mm/pat.c | 2 +-
arch/x86/pci/amd_bus.c | 4 +-
arch/x86/xen/setup.c | 6 +-
arch/x86/xen/smp.c | 8 ++--
arch/x86/xen/spinlock.c | 2 +-
arch/x86/xen/xen-ops.h | 2 +-
arch/xtensa/kernel/time.c | 2 +-
block/blk-softirq.c | 4 +-
drivers/acpi/bus.c | 2 +-
drivers/acpi/ec.c | 2 +-
drivers/acpi/numa.c | 2 +-
drivers/acpi/processor_core.c | 4 +-
drivers/acpi/processor_idle.c | 6 +-
drivers/base/cpu.c | 4 +-
drivers/base/topology.c | 8 ++--
drivers/cpufreq/cpufreq.c | 2 +-
drivers/cpufreq/cpufreq_stats.c | 2 +-
drivers/hwmon/coretemp.c | 4 +-
drivers/infiniband/hw/ehca/ehca_irq.c | 6 +-
drivers/s390/sysinfo.c | 2 +-
include/linux/cpu.h | 2 +-
include/linux/init.h | 12 ++--
init/calibrate.c | 6 +-
kernel/cpu.c | 6 +-
kernel/fork.c | 4 +-
kernel/hrtimer.c | 6 +-
kernel/rcuclassic.c | 6 +-
kernel/rcupreempt.c | 6 +-
kernel/relay.c | 2 +-
kernel/sched.c | 8 ++--
kernel/smp.c | 2 +-
kernel/softirq.c | 8 ++--
kernel/softlockup.c | 4 +-
kernel/timer.c | 10 ++--
lib/percpu_counter.c | 2 +-
mm/page-writeback.c | 4 +-
mm/page_alloc.c | 6 +-
mm/slab.c | 10 ++--
mm/slub.c | 4 +-
mm/vmstat.c | 6 +-
net/iucv/iucv.c | 2 +-
173 files changed, 645 insertions(+), 645 deletions(-)
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH] kbuild: drop cpuinit/cpuexit checks in modpost 2008-10-24 21:20 [pull request] getting rid of __cpuinit Arjan van de Ven @ 2008-10-24 21:37 ` Sam Ravnborg 2008-10-25 23:56 ` Arjan van de Ven 2008-10-25 7:59 ` [pull request] getting rid of __cpuinit Sam Ravnborg 1 sibling, 1 reply; 11+ messages in thread From: Sam Ravnborg @ 2008-10-24 21:37 UTC (permalink / raw) To: Arjan van de Ven; +Cc: torvalds, linux-kernel, Matt Mackall With the removal of cpuinit/cpuexit we no longer need to do section mismatch checks on these sections. Drop it from modpost. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> --- Can you add this to the queue too. Thanks, Sam diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 8892161..58041e3 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -753,14 +753,14 @@ static int check_section(const char *modname, const char *sec) #define ALL_INIT_DATA_SECTIONS \ - ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" + ".init.data$", ".devinit.data$", ".meminit.data$" #define ALL_EXIT_DATA_SECTIONS \ - ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" + ".exit.data$", ".devexit.data$", ".memexit.data$" #define ALL_INIT_TEXT_SECTIONS \ - ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" + ".init.text$", ".devinit.text$", ".meminit.text$" #define ALL_EXIT_TEXT_SECTIONS \ - ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" + ".exit.text$", ".devexit.text$", ".memexit.text$" #define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS #define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS @@ -770,12 +770,10 @@ static int check_section(const char *modname, const char *sec) #define INIT_SECTIONS ".init.data$", ".init.text$" #define DEV_INIT_SECTIONS ".devinit.data$", ".devinit.text$" -#define CPU_INIT_SECTIONS ".cpuinit.data$", ".cpuinit.text$" #define MEM_INIT_SECTIONS ".meminit.data$", ".meminit.text$" #define EXIT_SECTIONS ".exit.data$", ".exit.text$" #define DEV_EXIT_SECTIONS ".devexit.data$", ".devexit.text$" -#define CPU_EXIT_SECTIONS ".cpuexit.data$", ".cpuexit.text$" #define MEM_EXIT_SECTIONS ".memexit.data$", ".memexit.text$" /* init data sections */ @@ -862,15 +860,15 @@ const struct sectioncheck sectioncheck[] = { .tosec = { ALL_EXIT_SECTIONS, NULL }, .mismatch = DATA_TO_EXIT, }, -/* Do not reference init code/data from devinit/cpuinit/meminit code/data */ +/* Do not reference init code/data from devinit/meminit code/data */ { - .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL }, + .fromsec = { DEV_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL }, .tosec = { INIT_SECTIONS, NULL }, .mismatch = XXXINIT_TO_INIT, }, -/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ +/* Do not reference exit code/data from devexit/memexit code/data */ { - .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL }, + .fromsec = { DEV_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL }, .tosec = { EXIT_SECTIONS, NULL }, .mismatch = XXXEXIT_TO_EXIT, }, @@ -1085,7 +1083,6 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, /* * Convert a section name to the function/data attribute * .init.text => __init - * .cpuinit.data => __cpudata * .memexitconst => __memconst * etc. */ ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH] kbuild: drop cpuinit/cpuexit checks in modpost 2008-10-24 21:37 ` [PATCH] kbuild: drop cpuinit/cpuexit checks in modpost Sam Ravnborg @ 2008-10-25 23:56 ` Arjan van de Ven 0 siblings, 0 replies; 11+ messages in thread From: Arjan van de Ven @ 2008-10-25 23:56 UTC (permalink / raw) To: Sam Ravnborg; +Cc: torvalds, linux-kernel, Matt Mackall On Fri, 24 Oct 2008 23:37:10 +0200 Sam Ravnborg <sam@ravnborg.org> wrote: > Can you add this to the queue too. applied and git-pushed -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-24 21:20 [pull request] getting rid of __cpuinit Arjan van de Ven 2008-10-24 21:37 ` [PATCH] kbuild: drop cpuinit/cpuexit checks in modpost Sam Ravnborg @ 2008-10-25 7:59 ` Sam Ravnborg 2008-10-25 14:00 ` Arjan van de Ven 1 sibling, 1 reply; 11+ messages in thread From: Sam Ravnborg @ 2008-10-25 7:59 UTC (permalink / raw) To: Arjan van de Ven; +Cc: torvalds, linux-kernel, Matt Mackall On Fri, Oct 24, 2008 at 02:20:56PM -0700, Arjan van de Ven wrote: > Hi Linus, > > this is one of those pull requests for which the best timing is likely at the > end of the merge window due to touching a large number of files in a trivial way. > In fact, 6 of the 8 patches were done via regexps: > > find -name "*.c" | xargs sed -i "s/^__cpuinit //g" > find arch/ -name "*.h" | xargs sed -i "s/ __cpuinit//g" > find -name "*.c" | xargs sed -i "s/ __cpuinit$//g" > find -name "*.c" | xargs sed -i "s/ __cpuinitdata//g" > find -name "*.c" | xargs sed -i "s/ __cpuexit / /g" > find -name "*.c" | xargs sed -i "s/ __cpuinit / /g" > > (I suppose asking for a "git sed" is too much to do...) > > The point of this series is to get rid of __cpuinit. (I'll be working on other __XXXXinit after this) > __cpuinit is a NOOP for CONFIG_HOTPLUG_CPU, which on for just about anybody in practice > (in fact I had to disable 6 common options to even be ABLE to turn it off for size testing) > and all distros also ship with it enabled. > > Yet it's a rather error prone construct since the rules of this sort of __XXXXinit thing are > rather complex and convoluted.. better to just get rid of it entirely. > > As for the code size effect, after I spent a bunch of time cursing and trying to find out > how to disable HOTPLUG_CPU, I managed to get an x86-64 build that actually shows how much space > we ACTUALLY save with all the __cpuinit's in the tree... it's less than 2Kb. That is, if you manage > to turn it actually off. > > text data bss dec hex filename > 4618096 1358684 848588 6825368 682598 vmlinux.before > 4619965 1356908 848716 6825589 682675 vmlinux.after The interesting number here is the size of the cpuinit/cpuexit sections. cpuinit sections are discarded after init and cpuexit sections are discarded if you do not use modules. Can you share these numbers with us? Sam ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 7:59 ` [pull request] getting rid of __cpuinit Sam Ravnborg @ 2008-10-25 14:00 ` Arjan van de Ven 2008-10-25 14:35 ` Sam Ravnborg 0 siblings, 1 reply; 11+ messages in thread From: Arjan van de Ven @ 2008-10-25 14:00 UTC (permalink / raw) To: Sam Ravnborg; +Cc: torvalds, linux-kernel, Matt Mackall On Sat, 25 Oct 2008 09:59:25 +0200 Sam Ravnborg <sam@ravnborg.org> wrote: > > text data bss dec > > hex filename 4618096 1358684 848588 > > 6825368 682598 vmlinux.before 4619965 > > 1356908 848716 6825589 682675 vmlinux.after > > The interesting number here is the size of the cpuinit/cpuexit > sections. cpuinit sections are discarded after init and cpuexit > sections are discarded if you do not use modules. > > Can you share these numbers with us? those sections don't actually exist because of the linker script magic... -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 14:00 ` Arjan van de Ven @ 2008-10-25 14:35 ` Sam Ravnborg 2008-10-25 15:06 ` Arjan van de Ven 0 siblings, 1 reply; 11+ messages in thread From: Sam Ravnborg @ 2008-10-25 14:35 UTC (permalink / raw) To: Arjan van de Ven; +Cc: torvalds, linux-kernel, Matt Mackall On Sat, Oct 25, 2008 at 07:00:43AM -0700, Arjan van de Ven wrote: > On Sat, 25 Oct 2008 09:59:25 +0200 > Sam Ravnborg <sam@ravnborg.org> wrote: > > > > text data bss dec > > > hex filename 4618096 1358684 848588 > > > 6825368 682598 vmlinux.before 4619965 > > > 1356908 848716 6825589 682675 vmlinux.after > > > > The interesting number here is the size of the cpuinit/cpuexit > > sections. cpuinit sections are discarded after init and cpuexit > > sections are discarded if you do not use modules. > > > > Can you share these numbers with us? > > those sections don't actually exist because of the linker script > magic... The code exist in both the before and after case, only in the after case you cannot distingush them. Your patch simply moves code/data from the cpuinit/exit sections to .text/.data. So if you look at the size of the cpuinit/exit sections in the before case you get the real space saving that is lost in the embedded case after your patch is applied. The space savings that happen after early init. As for the complexity of especially the cpuinit/exit stuff the reason is that whoever started to use this mechnishm extended the __cpuinit case to be: a) Code that is only used during early init and can be discarded b) Code that is only used for CPU hotplugging The a) case is the traditional way __fooinit is used. The b) case is usually handled by our configuration but for CPU hotplugging it was misused. Let us please get the numbers correct before we rip it out. Sam ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 14:35 ` Sam Ravnborg @ 2008-10-25 15:06 ` Arjan van de Ven 2008-10-25 16:21 ` Sam Ravnborg 0 siblings, 1 reply; 11+ messages in thread From: Arjan van de Ven @ 2008-10-25 15:06 UTC (permalink / raw) To: Sam Ravnborg; +Cc: torvalds, linux-kernel, Matt Mackall On Sat, 25 Oct 2008 16:35:28 +0200 Sam Ravnborg <sam@ravnborg.org> wrote: > So if you look at the size of the cpuinit/exit sections in the > before case you get the real space saving that is lost in the > embedded case after your patch is applied. > The space savings that happen after early init. [linux.trees.git]# objdump -h vmlinux.before | grep init.text 25 .init.text 00037c25 ffffffff8152a000 000000000152a000 0092a000 [inux.trees.git]# objdump -h vmlinux.after | grep init.text 25 .init.text 000316c2 ffffffff81542000 0000000001542000 00942000 ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 15:06 ` Arjan van de Ven @ 2008-10-25 16:21 ` Sam Ravnborg 2008-10-25 16:29 ` Arjan van de Ven 0 siblings, 1 reply; 11+ messages in thread From: Sam Ravnborg @ 2008-10-25 16:21 UTC (permalink / raw) To: Arjan van de Ven; +Cc: torvalds, linux-kernel, Matt Mackall On Sat, Oct 25, 2008 at 08:06:38AM -0700, Arjan van de Ven wrote: > On Sat, 25 Oct 2008 16:35:28 +0200 > Sam Ravnborg <sam@ravnborg.org> wrote: > > So if you look at the size of the cpuinit/exit sections in the > > before case you get the real space saving that is lost in the > > embedded case after your patch is applied. > > The space savings that happen after early init. > > [linux.trees.git]# objdump -h vmlinux.before | grep init.text > 25 .init.text 00037c25 ffffffff8152a000 000000000152a000 0092a000 > [inux.trees.git]# objdump -h vmlinux.after | grep init.text > 25 .init.text 000316c2 ffffffff81542000 0000000001542000 00942000 So with your config we will loose a saving of 25955 bytes of text. I tried to look a the numbers of a defconfig build here. cpuinit.text equals 0x5d97 = 23959 cpuinit.data equals 0x3574 = 13684 [objdump of vmlinux.o gives you the size of the cpuinit sections] So if we decide to drop cpuinit then it should be based on the above figure and not the 2k figure you gave in the original mail. Or even better we should see the difference with a typical embedded configuration and not some big defconfig build. I will assume the saving is less on a typical embedded configuration. Sam ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 16:21 ` Sam Ravnborg @ 2008-10-25 16:29 ` Arjan van de Ven 2008-10-25 18:20 ` Rafael J. Wysocki 0 siblings, 1 reply; 11+ messages in thread From: Arjan van de Ven @ 2008-10-25 16:29 UTC (permalink / raw) To: Sam Ravnborg; +Cc: torvalds, linux-kernel, Matt Mackall On Sat, 25 Oct 2008 18:21:16 +0200 Sam Ravnborg <sam@ravnborg.org> wrote: > On Sat, Oct 25, 2008 at 08:06:38AM -0700, Arjan van de Ven wrote: > > On Sat, 25 Oct 2008 16:35:28 +0200 > > Sam Ravnborg <sam@ravnborg.org> wrote: > > > So if you look at the size of the cpuinit/exit sections in the > > > before case you get the real space saving that is lost in the > > > embedded case after your patch is applied. > > > The space savings that happen after early init. > > > > [linux.trees.git]# objdump -h vmlinux.before | grep init.text > > 25 .init.text 00037c25 ffffffff8152a000 000000000152a000 > > 0092a000 [inux.trees.git]# objdump -h vmlinux.after | grep > > init.text 25 .init.text 000316c2 ffffffff81542000 > > 0000000001542000 00942000 > > So with your config we will loose a saving of 25955 bytes > of text. > > I tried to look a the numbers of a defconfig build here. > cpuinit.text equals 0x5d97 = 23959 > cpuinit.data equals 0x3574 = 13684 > > [objdump of vmlinux.o gives you the size of the cpuinit sections] > > So if we decide to drop cpuinit then it should be based on the > above figure and not the 2k figure you gave in the original mail. > > Or even better we should see the difference with a typical > embedded configuration and not some big defconfig build. > I will assume the saving is less on a typical embedded > configuration. it will be; on x86 you end up inheriting all cpu vendors init code. on embedded you only have the dedicated CPU code. ... just that on x86... nobody seems to be in this position, it's almost impossble to have HOTPLUG_CPU even be asked. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 16:29 ` Arjan van de Ven @ 2008-10-25 18:20 ` Rafael J. Wysocki 2008-10-25 21:36 ` Sam Ravnborg 0 siblings, 1 reply; 11+ messages in thread From: Rafael J. Wysocki @ 2008-10-25 18:20 UTC (permalink / raw) To: Arjan van de Ven; +Cc: Sam Ravnborg, torvalds, linux-kernel, Matt Mackall On Saturday, 25 of October 2008, Arjan van de Ven wrote: > On Sat, 25 Oct 2008 18:21:16 +0200 > Sam Ravnborg <sam@ravnborg.org> wrote: > > > On Sat, Oct 25, 2008 at 08:06:38AM -0700, Arjan van de Ven wrote: > > > On Sat, 25 Oct 2008 16:35:28 +0200 > > > Sam Ravnborg <sam@ravnborg.org> wrote: > > > > So if you look at the size of the cpuinit/exit sections in the > > > > before case you get the real space saving that is lost in the > > > > embedded case after your patch is applied. > > > > The space savings that happen after early init. > > > > > > [linux.trees.git]# objdump -h vmlinux.before | grep init.text > > > 25 .init.text 00037c25 ffffffff8152a000 000000000152a000 > > > 0092a000 [inux.trees.git]# objdump -h vmlinux.after | grep > > > init.text 25 .init.text 000316c2 ffffffff81542000 > > > 0000000001542000 00942000 > > > > So with your config we will loose a saving of 25955 bytes > > of text. > > > > I tried to look a the numbers of a defconfig build here. > > cpuinit.text equals 0x5d97 = 23959 > > cpuinit.data equals 0x3574 = 13684 > > > > [objdump of vmlinux.o gives you the size of the cpuinit sections] > > > > So if we decide to drop cpuinit then it should be based on the > > above figure and not the 2k figure you gave in the original mail. > > > > Or even better we should see the difference with a typical > > embedded configuration and not some big defconfig build. > > I will assume the saving is less on a typical embedded > > configuration. > > it will be; on x86 you end up inheriting all cpu vendors init code. > on embedded you only have the dedicated CPU code. > > ... just that on x86... nobody seems to be in this position, it's > almost impossble to have HOTPLUG_CPU even be asked. FWIW, I like the idea of removing __cpuinit. It often is quite difficult to determine if given piece of code should be marked as __cpuinit and that leads to bugs that are not so easy to resolve. Thanks, Rafael ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [pull request] getting rid of __cpuinit 2008-10-25 18:20 ` Rafael J. Wysocki @ 2008-10-25 21:36 ` Sam Ravnborg 0 siblings, 0 replies; 11+ messages in thread From: Sam Ravnborg @ 2008-10-25 21:36 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: Arjan van de Ven, torvalds, linux-kernel, Matt Mackall > > > I tried to look a the numbers of a defconfig build here. > > > cpuinit.text equals 0x5d97 = 23959 > > > cpuinit.data equals 0x3574 = 13684 > > > > > > [objdump of vmlinux.o gives you the size of the cpuinit sections] > > > > > > So if we decide to drop cpuinit then it should be based on the > > > above figure and not the 2k figure you gave in the original mail. > > > > > > Or even better we should see the difference with a typical > > > embedded configuration and not some big defconfig build. > > > I will assume the saving is less on a typical embedded > > > configuration. > > > > it will be; on x86 you end up inheriting all cpu vendors init code. > > on embedded you only have the dedicated CPU code. > > > > ... just that on x86... nobody seems to be in this position, it's > > almost impossble to have HOTPLUG_CPU even be asked. > > FWIW, I like the idea of removing __cpuinit. It often is quite difficult to > determine if given piece of code should be marked as __cpuinit and that leads > to bugs that are not so easy to resolve. Getting rid of __cpuinit would be good - I do not questions this. I only want the decision to be taken based on the correct numbers, which Arjan failed to provide initially. I decided to try to build a typical arm target - netwinder. It had HOTPLUG disabled which is why I took this one. objdump -h a/vmlinux.o | grep cpu 4 .cpuinit.text 000006ac 00000000 00000000 0023e3e4 2**2 41 .cpuinit.data 00000040 00000000 00000000 002c31a8 2**2 objdump -h a/vmlinux.o | grep text 0 .text 00227b44 00000000 00000000 00000040 2**5 1 .text.head 00000240 00000000 00000000 00227ba0 2**5 2 .init.text 000150b0 00000000 00000000 00227de0 2**5 4 .cpuinit.text 000006ac 00000000 00000000 0023e3e4 2**2 7 .devinit.text 00005c24 00000000 00000000 0023f78c 2**2 9 .exit.text 00001124 00000000 00000000 002453e4 2**2 11 .meminit.text 000002d4 00000000 00000000 002482b0 2**2 12 .devexit.text 00000348 00000000 00000000 00248584 2**2 So we see that for this config on arm we only save ~1700 bytes by the cpuinit stuff. And for data we save even less. __cpuinit is almost not used in arm specific code so what we have here is the savings from the shared code. Considering these numbers the gain/pain ratio is too low and I agree that the cpuinit stuff should go. The reports that removing cpuinit/exit stuff adds a new set of warnings should just be looked at. Except from the tricky __cpuinit cases it is almost always trivial to fix when you have understood the problem. Sam ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2008-10-25 23:56 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2008-10-24 21:20 [pull request] getting rid of __cpuinit Arjan van de Ven 2008-10-24 21:37 ` [PATCH] kbuild: drop cpuinit/cpuexit checks in modpost Sam Ravnborg 2008-10-25 23:56 ` Arjan van de Ven 2008-10-25 7:59 ` [pull request] getting rid of __cpuinit Sam Ravnborg 2008-10-25 14:00 ` Arjan van de Ven 2008-10-25 14:35 ` Sam Ravnborg 2008-10-25 15:06 ` Arjan van de Ven 2008-10-25 16:21 ` Sam Ravnborg 2008-10-25 16:29 ` Arjan van de Ven 2008-10-25 18:20 ` Rafael J. Wysocki 2008-10-25 21:36 ` Sam Ravnborg
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