[hellogcc] Re: [PATCH] Built kernel without -O2 option

  • From: Hui Zhu <teawater@xxxxxxxxx>
  • To: linux-kernel@xxxxxxxxxxxxxxx, Kevin Pouget <kevin.pouget@xxxxxxxxx>, Petr Hluzín <petr.hluzin@xxxxxxxxx>
  • Date: Thu, 17 Feb 2011 10:43:31 +0800

https://lkml.org/lkml/2010/11/28/211
https://lkml.org/lkml/2011/1/24/24
https://lkml.org/lkml/2011/1/27/410

Hi,

According to the comments from Petr, I make a new version that change
the options name to "Compile with almost no optimization".
Thanks for your help, Petr.

Kevin, I am not sure you have try the patch with ARM, I got thread
stack overflow in a ARM board.  I try to increase the THREAD_SIZE like
what I do in x86.  But after I try change THREAD_SIZE_ORDER of arm to
2 and update the code in entry-header.S.
But I got another crash.  Wish somebody can help me with that part.

Thanks,
Hui

Signed-off-by: Hui Zhu <teawater@xxxxxxxxx>
---
 Makefile                                        |    2 ++
 arch/arm/include/asm/tlbflush.h                 |    4 ++++
 arch/arm/mm/dma-mapping.c                       |    2 ++
 arch/arm/mm/flush.c                             |    2 ++
 arch/x86/crypto/Makefile                        |    6 ++++++
 arch/x86/include/asm/page_64_types.h            |    4 ++++
 arch/x86/include/asm/uaccess_32.h               |    4 ++++
 arch/x86/kernel/Makefile                        |    9 +++++++++
 arch/x86/kvm/Makefile                           |    6 ++++++
 arch/x86/lib/Makefile                           |    4 ++++
 arch/x86/power/Makefile                         |    4 ++++
 crypto/Makefile                                 |    4 ++++
 drivers/char/mwave/Makefile                     |    4 ++++
 drivers/gpu/drm/i915/Makefile                   |    4 ++++
 drivers/gpu/drm/i915/i915_drv.h                 |    4 ++++
 drivers/gpu/drm/nouveau/Makefile                |    4 ++++
 drivers/gpu/drm/radeon/Makefile                 |    4 ++++
 drivers/infiniband/hw/qib/Makefile              |    4 ++++
 drivers/net/can/sja1000/Makefile                |    4 ++++
 drivers/staging/comedi/drivers/Makefile         |    4 ++++
 drivers/staging/et131x/et1310_address_map.h     |    8 ++++++++
 drivers/staging/rtl8187se/ieee80211/ieee80211.h |    8 ++++++++
 drivers/staging/wlags49_h2/wl_internal.h        |    9 ++++++++-
 drivers/usb/gadget/f_loopback.c                 |    2 ++
 drivers/usb/gadget/f_sourcesink.c               |    2 ++
 drivers/usb/gadget/g_zero.h                     |    2 ++
 drivers/usb/host/Makefile                       |    4 ++++
 fs/Makefile                                     |    5 +++++
 include/asm-generic/cmpxchg-local.h             |    4 ++++
 include/linux/pagemap.h                         |    2 ++
 init/Kconfig                                    |    1 +
 kernel/kfifo.c                                  |    3 +++
 kernel/sched_autogroup.c                        |    4 ++++
 kernel/sched_autogroup.h                        |    4 ++++
 lib/Kconfig.debug                               |   10 ++++++++++
 lib/raid6/Makefile                              |    6 ++++++
 mm/Makefile                                     |    6 ++++++
 mm/memory.c                                     |    6 ++++++
 mm/mincore.c                                    |    2 ++
 mm/percpu.c                                     |    4 ++++
 mm/rmap.c                                       |    2 ++
 net/mac80211/cfg.c                              |    2 ++
 net/mac80211/iface.c                            |    8 ++++++++
 net/mac80211/mesh.h                             |    2 ++
 net/mac80211/rx.c                               |    8 ++++++++
 net/mac80211/sta_info.c                         |    2 ++
 net/mac80211/status.c                           |    2 ++
 net/mac80211/tx.c                               |    4 ++++
 net/netfilter/nf_conntrack_pptp.c               |    3 ++-
 49 files changed, 206 insertions(+), 2 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -541,8 +541,10 @@ all: vmlinux
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 KBUILD_CFLAGS  += -Os
 else
+ifndef CONFIG_CC_NO_OPTIMIZATION
 KBUILD_CFLAGS  += -O2
 endif
+endif

 include $(srctree)/arch/$(SRCARCH)/Makefile

--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -250,7 +250,11 @@ extern void __cpu_flush_kern_tlb_range(u

 extern struct cpu_tlb_fns cpu_tlb;

+#ifdef MULTI_TLB
 #define __cpu_tlb_flags                        cpu_tlb.tlb_flags
+#else
+#define __cpu_tlb_flags                        0
+#endif

 /*
  *     TLB Management
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -468,6 +468,7 @@ static void dma_cache_maint_page(struct
                void *vaddr;

                if (PageHighMem(page)) {
+#ifdef CONFIG_HIGHMEM
                        if (len + offset > PAGE_SIZE) {
                                if (offset >= PAGE_SIZE) {
                                        page += offset / PAGE_SIZE;
@@ -486,6 +487,7 @@ static void dma_cache_maint_page(struct
                                op(vaddr + offset, len, dir);
                                kunmap_atomic(vaddr);
                        }
+#endif
                } else {
                        vaddr = page_address(page) + offset;
                        op(vaddr, len, dir);
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -175,6 +175,7 @@ void __flush_dcache_page(struct address_
        if (!PageHighMem(page)) {
                __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
        } else {
+#ifdef CONFIG_HIGHMEM
                void *addr = kmap_high_get(page);
                if (addr) {
                        __cpuc_flush_dcache_area(addr, PAGE_SIZE);
@@ -185,6 +186,7 @@ void __flush_dcache_page(struct address_
                        __cpuc_flush_dcache_area(addr, PAGE_SIZE);
                        kunmap_atomic(addr);
                }
+#endif
        }

        /*
--- a/arch/x86/crypto/Makefile
+++ b/arch/x86/crypto/Makefile
@@ -2,6 +2,12 @@
 # Arch-specific CryptoAPI modules.
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_fpu.o                           += -O2
+CFLAGS_aesni-intel_glue.o              += -O2
+CFLAGS_ghash-clmulni-intel_glue.o      += -O2
+endif
+
 obj-$(CONFIG_CRYPTO_FPU) += fpu.o

 obj-$(CONFIG_CRYPTO_AES_586) += aes-i586.o
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -1,7 +1,11 @@
 #ifndef _ASM_X86_PAGE_64_DEFS_H
 #define _ASM_X86_PAGE_64_DEFS_H

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+#define THREAD_ORDER   2
+#else
 #define THREAD_ORDER   1
+#endif
 #define THREAD_SIZE  (PAGE_SIZE << THREAD_ORDER)
 #define CURRENT_MASK (~(THREAD_SIZE - 1))

--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -209,7 +209,11 @@ static inline unsigned long __must_check
        if (likely(sz == -1 || sz >= n))
                n = _copy_from_user(to, from, n);
        else
+#ifndef CONFIG_CC_NO_OPTIMIZATION
                copy_from_user_overflow();
+#else
+               n = -EFAULT;
+#endif

        return n;
 }
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -31,6 +31,15 @@ GCOV_PROFILE_hpet.o          := n
 GCOV_PROFILE_tsc.o             := n
 GCOV_PROFILE_paravirt.o                := n

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_process_$(BITS).o       += -O2
+CFLAGS_entry_$(BITS).o         += -O2
+CFLAGS_traps.o                 += -O2
+CFLAGS_i387.o                  += -O2
+CFLAGS_xsave.o                 += -O2
+CFLAGS_hpet.o                  += -O2
+endif
+
 obj-y                  := process_$(BITS).o signal.o entry_$(BITS).o
 obj-y                  += traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
 obj-y                  += time.o ioport.o ldt.o dumpstack.o
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -5,6 +5,12 @@ CFLAGS_x86.o := -I.
 CFLAGS_svm.o := -I.
 CFLAGS_vmx.o := -I.

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_x86.o           += -O2
+CFLAGS_emulate.o       += -O2
+CFLAGS_svm.o           += -O2
+endif
+
 kvm-y                  += $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o \
                                coalesced_mmio.o irq_comm.o eventfd.o \
                                assigned-dev.o)
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -2,6 +2,10 @@
 # Makefile for x86 specific library files.
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_memmove_64.o    += -O2
+endif
+
 inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk
 inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt
 quiet_cmd_inat_tables = GEN     $@
--- a/arch/x86/power/Makefile
+++ b/arch/x86/power/Makefile
@@ -3,5 +3,9 @@
 nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_cpu.o   := $(nostackp)

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_cpu.o   += -O2
+endif
+
 obj-$(CONFIG_PM_SLEEP)         += cpu.o
 obj-$(CONFIG_HIBERNATION)      += hibernate_$(BITS).o hibernate_asm_$(BITS).o
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -2,6 +2,10 @@
 # Cryptographic API
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_xor.o   += -O2
+endif
+
 obj-$(CONFIG_CRYPTO) += crypto.o
 crypto-y := api.o cipher.o compress.o

--- a/drivers/char/mwave/Makefile
+++ b/drivers/char/mwave/Makefile
@@ -4,6 +4,10 @@
 # See the README file in this directory for more info. <paulsch@xxxxxxxxxx>
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_smapi.o += -O2
+endif
+
 obj-$(CONFIG_MWAVE) += mwave.o

 mwave-y := mwavedd.o smapi.o tp3780i.o 3780i.o
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -2,6 +2,10 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_i915_gem.o      += -O2
+endif
+
 ccflags-y := -Iinclude/drm
 i915-y := i915_drv.o i915_dma.o i915_irq.o i915_mem.o \
          i915_debugfs.o \
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1225,7 +1225,11 @@ extern int intel_setup_gmbus(struct drm_
 extern void intel_teardown_gmbus(struct drm_device *dev);
 extern void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed);
 extern void intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit);
+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline bool intel_gmbus_is_forced_bit(struct i2c_adapter *adapter)
+#else
 extern inline bool intel_gmbus_is_forced_bit(struct i2c_adapter *adapter)
+#endif
 {
        return container_of(adapter, struct intel_gmbus, adapter)->force_bit;
 }
--- a/drivers/gpu/drm/nouveau/Makefile
+++ b/drivers/gpu/drm/nouveau/Makefile
@@ -2,6 +2,10 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_nv50_instmem.o  += -O2
+endif
+
 ccflags-y := -Iinclude/drm
 nouveau-y := nouveau_drv.o nouveau_state.o nouveau_channel.o nouveau_mem.o \
              nouveau_object.o nouveau_irq.o nouveau_notifier.o \
--- a/drivers/gpu/drm/radeon/Makefile
+++ b/drivers/gpu/drm/radeon/Makefile
@@ -2,6 +2,10 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_radeon_gem.o    += -O2
+endif
+
 ccflags-y := -Iinclude/drm

 hostprogs-y := mkregtable
--- a/drivers/infiniband/hw/qib/Makefile
+++ b/drivers/infiniband/hw/qib/Makefile
@@ -1,5 +1,9 @@
 obj-$(CONFIG_INFINIBAND_QIB) += ib_qib.o

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_qib_iba7322.o   += -O2
+endif
+
 ib_qib-y := qib_cq.o qib_diag.o qib_dma.o qib_driver.o qib_eeprom.o \
        qib_file_ops.o qib_fs.o qib_init.o qib_intr.o qib_keys.o \
        qib_mad.o qib_mmap.o qib_mr.o qib_pcie.o qib_pio_copy.o \
--- a/drivers/net/can/sja1000/Makefile
+++ b/drivers/net/can/sja1000/Makefile
@@ -2,6 +2,10 @@
 #  Makefile for the SJA1000 CAN controller drivers.
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_kvaser_pci.o    += -O2
+endif
+
 obj-$(CONFIG_CAN_SJA1000) += sja1000.o
 obj-$(CONFIG_CAN_SJA1000_ISA) += sja1000_isa.o
 obj-$(CONFIG_CAN_SJA1000_PLATFORM) += sja1000_platform.o
--- a/drivers/staging/comedi/drivers/Makefile
+++ b/drivers/staging/comedi/drivers/Makefile
@@ -1,6 +1,10 @@
 # Makefile for individual comedi drivers
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_cb_pcidas64.o   += -O2
+endif
+
 # Comedi "helper" modules
 obj-$(CONFIG_COMEDI)                   += pcm_common.o

--- a/drivers/staging/et131x/et1310_address_map.h
+++ b/drivers/staging/et131x/et1310_address_map.h
@@ -212,12 +212,20 @@ struct global_regs {                      /* Location: */
 #define INDEX10(x)     ((x) & ET_DMA10_MASK)
 #define INDEX4(x)      ((x) & ET_DMA4_MASK)

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline void add_10bit(u32 *v, int n)
+#else
 extern inline void add_10bit(u32 *v, int n)
+#endif
 {
        *v = INDEX10(*v + n) | (*v & ET_DMA10_WRAP);
 }

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline void add_12bit(u32 *v, int n)
+#else
 extern inline void add_12bit(u32 *v, int n)
+#endif
 {
        *v = INDEX12(*v + n) | (*v & ET_DMA12_WRAP);
 }
--- a/drivers/staging/rtl8187se/ieee80211/ieee80211.h
+++ b/drivers/staging/rtl8187se/ieee80211/ieee80211.h
@@ -1221,7 +1221,11 @@ static inline void *ieee80211_priv(struc
        return ((struct ieee80211_device *)netdev_priv(dev))->priv;
 }

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline int ieee80211_is_empty_essid(const char *essid, int essid_len)
+#else
 extern inline int ieee80211_is_empty_essid(const char *essid, int essid_len)
+#endif
 {
        /* Single white space is for Linksys APs */
        if (essid_len == 1 && essid[0] == ' ')
@@ -1263,7 +1267,11 @@ extern inline int ieee80211_is_valid_mod
        return 0;
 }

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline int ieee80211_get_hdrlen(u16 fc)
+#else
 extern inline int ieee80211_get_hdrlen(u16 fc)
+#endif
 {
        int hdrlen = 24;

--- a/drivers/staging/wlags49_h2/wl_internal.h
+++ b/drivers/staging/wlags49_h2/wl_internal.h
@@ -1022,8 +1022,11 @@ static inline void wl_unlock(struct wl_p
 /********************************************************************/
 /* Interrupt enable disable functions                               */
 /********************************************************************/
-
+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline void wl_act_int_on(struct wl_private *lp)
+#else
 extern inline void wl_act_int_on(struct wl_private *lp)
+#endif
 {
        /*
         * Only do something when the driver is handling
@@ -1035,7 +1038,11 @@ extern inline void wl_act_int_on(struct
        }
 }

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+static inline void wl_act_int_off(struct wl_private *lp)
+#else
 extern inline void wl_act_int_off(struct wl_private *lp)
+#endif
 {
        /*
         * Only do something when the driver is handling
--- a/drivers/usb/gadget/f_loopback.c
+++ b/drivers/usb/gadget/f_loopback.c
@@ -376,10 +376,12 @@ int __init loopback_add(struct usb_compo
                sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;

        /* support OTG systems */
+#ifdef CONFIG_USB_OTG
        if (gadget_is_otg(cdev->gadget)) {
                loopback_driver.descriptors = otg_desc;
                loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
        }
+#endif

        return usb_add_config(cdev, &loopback_driver, loopback_bind_config);
 }
--- a/drivers/usb/gadget/f_sourcesink.c
+++ b/drivers/usb/gadget/f_sourcesink.c
@@ -526,10 +526,12 @@ int __init sourcesink_add(struct usb_com
                sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;

        /* support OTG systems */
+#ifdef CONFIG_USB_OTG
        if (gadget_is_otg(cdev->gadget)) {
                sourcesink_driver.descriptors = otg_desc;
                sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
        }
+#endif

        return usb_add_config(cdev, &sourcesink_driver, sourcesink_bind_config);
 }
--- a/drivers/usb/gadget/g_zero.h
+++ b/drivers/usb/gadget/g_zero.h
@@ -10,7 +10,9 @@

 /* global state */
 extern unsigned buflen;
+#ifdef CONFIG_USB_OTG
 extern const struct usb_descriptor_header *otg_desc[];
+#endif

 /* common utilities */
 struct usb_request *alloc_ep_req(struct usb_ep *ep);
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -4,6 +4,10 @@

 ccflags-$(CONFIG_USB_DEBUG) := -DDEBUG

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_ehci-hcd.o      += -O2
+endif
+
 isp1760-y := isp1760-hcd.o isp1760-if.o

 fhci-y := fhci-hcd.o fhci-hub.o fhci-q.o
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -13,6 +13,11 @@ obj-y :=     open.o read_write.o file_table.
                pnode.o drop_caches.o splice.o sync.o utimes.o \
                stack.o fs_struct.o statfs.o

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_compat_ioctl.o  += -O2
+CFLAGS_binfmt_elf.o    += -O2
+endif
+
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=       buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
 else
--- a/include/asm-generic/cmpxchg-local.h
+++ b/include/asm-generic/cmpxchg-local.h
@@ -18,8 +18,10 @@ static inline unsigned long __cmpxchg_lo
        /*
         * Sanity checking, compile-time.
         */
+#if !(defined(CONFIG_CC_NO_OPTIMIZATION) && defined(CONFIG_ARM))
        if (size == 8 && sizeof(unsigned long) != 8)
                wrong_size_cmpxchg(ptr);
+#endif

        local_irq_save(flags);
        switch (size) {
@@ -39,8 +41,10 @@ static inline unsigned long __cmpxchg_lo
                if (prev == old)
                        *(u64 *)ptr = (u64)new;
                break;
+#if !(defined(CONFIG_CC_NO_OPTIMIZATION) && defined(CONFIG_ARM))
        default:
                wrong_size_cmpxchg(ptr);
+#endif
        }
        local_irq_restore(flags);
        return prev;
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -289,8 +289,10 @@ static inline pgoff_t linear_page_index(
                                        unsigned long address)
 {
        pgoff_t pgoff;
+#ifdef CONFIG_HUGETLBFS
        if (unlikely(is_vm_hugetlb_page(vma)))
                return linear_hugepage_index(vma, address);
+#endif
        pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
        pgoff += vma->vm_pgoff;
        return pgoff >> (PAGE_CACHE_SHIFT - PAGE_SHIFT);
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -886,6 +886,7 @@ endif

 config CC_OPTIMIZE_FOR_SIZE
        bool "Optimize for size"
+       depends on !CC_NO_OPTIMIZATION
        default y
        help
          Enabling this option will pass "-Os" instead of "-O2" to gcc
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -402,6 +402,9 @@ unsigned int __kfifo_max_r(unsigned int
                return max;
        return len;
 }
+#ifdef CONFIG_CC_NO_OPTIMIZATION
+EXPORT_SYMBOL(__kfifo_max_r);
+#endif

 #define        __KFIFO_PEEK(data, out, mask) \
        ((data)[(out) & (mask)])
--- a/kernel/sched_autogroup.c
+++ b/kernel/sched_autogroup.c
@@ -133,7 +133,11 @@ static inline bool task_group_is_autogro
        return tg != &root_task_group && tg->autogroup;
 }

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+struct task_group *
+#else
 static inline struct task_group *
+#endif
 autogroup_task_group(struct task_struct *p, struct task_group *tg)
 {
        int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
--- a/kernel/sched_autogroup.h
+++ b/kernel/sched_autogroup.h
@@ -8,7 +8,11 @@ struct autogroup {
        int                     nice;
 };

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+extern struct task_group *
+#else
 static inline struct task_group *
+#endif
 autogroup_task_group(struct task_struct *p, struct task_group *tg);

 #else /* !CONFIG_SCHED_AUTOGROUP */
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -136,6 +136,16 @@ config DEBUG_SECTION_MISMATCH
          - Enable verbose reporting from modpost to help solving
            the section mismatches reported.

+config CC_NO_OPTIMIZATION
+       bool "Compile with almost no optimization"
+       default n
+       help
+         Enabling this option will let gcc build kernel with no
+         optimization (where possible).
+         This makes debugging friendlier.
+
+         If unsure, say N.
+
 config DEBUG_KERNEL
        bool "Kernel debugging"
        help
--- a/lib/raid6/Makefile
+++ b/lib/raid6/Makefile
@@ -1,3 +1,9 @@
+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_mmx.o   += -O2
+CFLAGS_sse1.o  += -O2
+CFLAGS_sse2.o  += -O2
+endif
+
 obj-$(CONFIG_RAID6_PQ) += raid6_pq.o

 raid6_pq-y     += algos.o recov.o tables.o int1.o int2.o int4.o \
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -2,6 +2,12 @@
 # Makefile for the linux memory manager.
 #

+ifdef CONFIG_CC_NO_OPTIMIZATION
+CFLAGS_slob.o  += -O2
+CFLAGS_slab.o  += -O2
+CFLAGS_slub.o  += -O2
+endif
+
 mmu-y                  := nommu.o
 mmu-$(CONFIG_MMU)      := fremap.o highmem.o madvise.o memory.o mincore.o \
                           mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1317,8 +1317,10 @@ struct page *follow_page(struct vm_area_
                                spin_unlock(&mm->page_table_lock);
                                wait_split_huge_page(vma->anon_vma, pmd);
                        } else {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                                page = follow_trans_huge_pmd(mm, address,
                                                             pmd, flags);
+#endif
                                spin_unlock(&mm->page_table_lock);
                                goto out;
                        }
@@ -2773,7 +2775,9 @@ static int do_swap_page(struct mm_struct

        if (ksm_might_need_to_copy(page, vma, address)) {
                swapcache = page;
+#ifdef CONFIG_KSM
                page = ksm_does_need_to_copy(page, vma, address);
+#endif

                if (unlikely(!page)) {
                        ret = VM_FAULT_OOM;
@@ -3306,11 +3310,13 @@ int handle_mm_fault(struct mm_struct *mm
                pmd_t orig_pmd = *pmd;
                barrier();
                if (pmd_trans_huge(orig_pmd)) {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                        if (flags & FAULT_FLAG_WRITE &&
                            !pmd_write(orig_pmd) &&
                            !pmd_trans_splitting(orig_pmd))
                                return do_huge_pmd_wp_page(mm, vma, address,
                                                           pmd, orig_pmd);
+#endif
                        return 0;
                }
        }
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -155,10 +155,12 @@ static void mincore_pmd_range(struct vm_
        do {
                next = pmd_addr_end(addr, end);
                if (pmd_trans_huge(*pmd)) {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                        if (mincore_huge_pmd(vma, pmd, addr, next, vec)) {
                                vec += (next - addr) >> PAGE_SHIFT;
                                continue;
                        }
+#endif
                        /* fall through */
                }
                if (pmd_none_or_clear_bad(pmd))
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1886,7 +1886,11 @@ void __init percpu_init_late(void)
                int *map;
                const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]);

+#ifdef CONFIG_CC_NO_OPTIMIZATION
+               BUG_ON(size > PAGE_SIZE);
+#else
                BUILD_BUG_ON(size > PAGE_SIZE);
+#endif

                map = pcpu_mem_alloc(size);
                BUG_ON(!map);
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -515,6 +515,7 @@ int page_referenced_one(struct page *pag
                referenced++;

        if (unlikely(PageTransHuge(page))) {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                pmd_t *pmd;

                spin_lock(&mm->page_table_lock);
@@ -524,6 +525,7 @@ int page_referenced_one(struct page *pag
                    pmdp_clear_flush_young_notify(vma, address, pmd))
                        referenced++;
                spin_unlock(&mm->page_table_lock);
+#endif
        } else {
                pte_t *pte;
                spinlock_t *ptl;
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -699,6 +699,7 @@ static void sta_apply_parameters(struct
                                                  params->ht_capa,
                                                  &sta->sta.ht_cap);

+#ifdef CONFIG_MAC80211_MESH
        if (ieee80211_vif_is_mesh(&sdata->vif) && params->plink_action) {
                switch (params->plink_action) {
                case PLINK_ACTION_OPEN:
@@ -709,6 +710,7 @@ static void sta_apply_parameters(struct
                        break;
                }
        }
+#endif
 }

 static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev,
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -620,8 +620,10 @@ static void ieee80211_teardown_sdata(str
                __skb_queue_purge(&sdata->fragments[i].skb_list);
        sdata->fragment_next = 0;

+#ifdef CONFIG_MAC80211_MESH
        if (ieee80211_vif_is_mesh(&sdata->vif))
                mesh_rmc_free(sdata);
+#endif

        flushed = sta_info_flush(local, sdata);
        WARN_ON(flushed);
@@ -797,7 +799,9 @@ static void ieee80211_iface_work(struct
                case NL80211_IFTYPE_MESH_POINT:
                        if (!ieee80211_vif_is_mesh(&sdata->vif))
                                break;
+#ifdef CONFIG_MAC80211_MESH
                        ieee80211_mesh_rx_queued_mgmt(sdata, skb);
+#endif
                        break;
                default:
                        WARN(1, "frame for unexpected interface type");
@@ -818,7 +822,9 @@ static void ieee80211_iface_work(struct
        case NL80211_IFTYPE_MESH_POINT:
                if (!ieee80211_vif_is_mesh(&sdata->vif))
                        break;
+#ifdef CONFIG_MAC80211_MESH
                ieee80211_mesh_work(sdata);
+#endif
                break;
        default:
                break;
@@ -872,8 +878,10 @@ static void ieee80211_setup_sdata(struct
                ieee80211_ibss_setup_sdata(sdata);
                break;
        case NL80211_IFTYPE_MESH_POINT:
+#ifdef CONFIG_MAC80211_MESH
                if (ieee80211_vif_is_mesh(&sdata->vif))
                        ieee80211_mesh_init_sdata(sdata);
+#endif
                break;
        case NL80211_IFTYPE_MONITOR:
                sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -189,8 +189,10 @@ int ieee80211_fill_mesh_addresses(struct
 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
                struct ieee80211_sub_if_data *sdata, char *addr4or5,
                char *addr6);
+#ifdef CONFIG_MAC80211_MESH
 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
                struct ieee80211_sub_if_data *sdata);
+#endif
 bool mesh_matches_local(struct ieee802_11_elems *ie,
                struct ieee80211_sub_if_data *sdata);
 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -453,6 +453,14 @@ static int ieee80211_get_mmie_keyidx(str
 }


+#ifndef CONFIG_MAC80211_MESH
+static int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
+                  struct ieee80211_sub_if_data *sdata)
+{
+       return 0;
+}
+#endif
+
 static ieee80211_rx_result
 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 {
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -470,8 +470,10 @@ int sta_info_insert_rcu(struct sta_info
        rcu_read_lock();
        mutex_unlock(&local->sta_mtx);

+#ifdef CONFIG_MAC80211_MESH
        if (ieee80211_vif_is_mesh(&sdata->vif))
                mesh_accept_plinks_update(sdata);
+#endif

        return 0;
  out_free:
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -247,8 +247,10 @@ void ieee80211_tx_status(struct ieee8021
                }

                rate_control_tx_status(local, sband, sta, skb);
+#ifdef CONFIG_MAC80211_MESH
                if (ieee80211_vif_is_mesh(&sta->sdata->vif))
                        ieee80211s_update_metric(local, sta, skb);
+#endif

                if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
                        ieee80211_frame_acked(sta, skb);
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1638,6 +1638,7 @@ static void ieee80211_xmit(struct ieee80
        hdr = (struct ieee80211_hdr *) skb->data;
        info->control.vif = &sdata->vif;

+#ifdef CONFIG_MAC80211_MESH
        if (ieee80211_vif_is_mesh(&sdata->vif) &&
            ieee80211_is_data(hdr->frame_control) &&
                !is_multicast_ether_addr(hdr->addr1))
@@ -1646,6 +1647,7 @@ static void ieee80211_xmit(struct ieee80
                                rcu_read_unlock();
                                return;
                        }
+#endif

        ieee80211_set_qos_hdr(local, skb);
        ieee80211_tx(sdata, skb, false);
@@ -2325,7 +2327,9 @@ struct sk_buff *ieee80211_beacon_get_tim
                *pos++ = WLAN_EID_SSID;
                *pos++ = 0x0;

+#ifdef CONFIG_MAC80211_MESH
                mesh_mgmt_ies_add(skb, sdata);
+#endif
        } else {
                WARN_ON(1);
                goto out;
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -67,7 +67,8 @@ void
                             struct nf_conntrack_expect *exp) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_expectfn);

-#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
+#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG) \
+    || defined(CONFIG_CC_NO_OPTIMIZATION)
 /* PptpControlMessageType names */
 const char *const pptp_msg_name[] = {
        "UNKNOWN_MESSAGE",

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