x86, 64bit: Always make MAX_APICS to 32768
PATCH 1/1 x86, 64bit: Always make MAX_APICS to 32768
Found one x2apic pre-enabled system, x2apic_mode suddenly get corrupted after register some cpus. when compiled CONFIG_NR_CPUS=255 instead of 512
It turns out that generic_processor_info() ==> phyid_set(apicid, phys_cpu_present_map) cause the problem.
phys_cpu_present_map is with MAX_APICS bits. and pre-enabled system some cpus apic id > 255.
the variable after phys_cpu_present_map may get corrupted.... siliently...
ffffffff828e8420 B phys_cpu_present_mapffffffff828e8440 B apic_verbosityffffffff828e8444 B local_apic_timer_c2_okffffffff828e8448 B disable_apicffffffff828e844c B x2apic_modeffffffff828e8450 B x2apic_disabledffffffff828e8454 B num_processors
...
Actually phys_cpu_present_map is referenced via apic id, instead index. we should use MAX_LOCAL_APIC instead MAX_APICIS. but that is another header.
So just let MAX_APICS equal to MAX_LOCAL_APIC at this point. esp for 64 bit will be 32768 in all cases.
--- arch/x86/include/asm/mpspec_def.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
arch/x86/include/asm/mpspec_def.h +1 -5
@@ -17,11 +17,7 @@# define MAX_MPC_ENTRY 1024# define MAX_APICS 256#else -# if NR_CPUS <=255 -# define MAX_APICS 255 -# else -# define MAX_APICS 32768 -# endif +# define MAX_APICS 32768#endif /* Intel MP Floating Pointer Structure */
Quoted 38 lines · Yinghai Lu
Found one x2apic pre-enabled system,
x2apic_modesuddenly get corrupted after register some cpus. when compiledCONFIG_NR_CPUS=255instead of 512It turns out that
generic_processor_info()==>phyid_set(apicid, phys_cpu_present_map)cause the problem.
phys_cpu_present_mapis withMAX_APICSbits. and pre-enabled system some cpus apic id > 255.the variable after
phys_cpu_present_mapmay get corrupted.... siliently...
ffffffff828e8420Bphys_cpu_present_mapffffffff828e8440Bapic_verbosityffffffff828e8444Blocal_apic_timer_c2_okffffffff828e8448Bdisable_apicffffffff828e844cBx2apic_modeffffffff828e8450Bx2apic_disabledffffffff828e8454Bnum_processors
...Actually
phys_cpu_present_mapis referenced via apic id, instead index. we should useMAX_LOCAL_APICinsteadMAX_APICIS. but that is another header.So just let
MAX_APICSequal toMAX_LOCAL_APICat this point. esp for 64 bit will be 32768 in all cases.Signed-off-by Yinghai Lu <[email protected]>--- arch/x86/include/asm/mpspec_def.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)Index:
linux-2.6/arch/x86/include/asm/mpspec_def.h
===================================================================arch/x86/include/asm/mpspec_def.h +0
-0@@ -17,11 +17,7 @@# define MAX_MPC_ENTRY 1024# define MAX_APICS 256
arch/x86/include/asm/mpspec_def.h line 23
Quoted 10 lines
arch/x86/include/asm/mpspec_def.h +1
-5#else -# if NR_CPUS <=255 -# define MAX_APICS 255 -# else -# define MAX_APICS 32768 -# endif +# define MAX_APICS 32768#endif /* Intel MP Floating Pointer Structure */
Please fix the real bug first: the lack of boundary checks when we set phys_cpu_present_map!
Then, once that bitmap op is not corrupting nearby variables silently but triggers a fail-safe logic instead (ignoring apics that go outside the supported range? printk-ing a warning?) can we think about upping the limit.
But even with the limit upping, please show (in the changelog) a before/after 'size vmlinux' comparison, to make sure that this rather drastic change of the limit does not waste unreasonable amounts of memory.
Thanks,
Ingo
Quoted 50 lines · Ingo Molnar
Quoted 47 lines · Yinghai Lu
Found one x2apic pre-enabled system,
x2apic_modesuddenly get corrupted after register some cpus. when compiledCONFIG_NR_CPUS=255instead of 512It turns out that
generic_processor_info()==>phyid_set(apicid, phys_cpu_present_map)cause the problem.
phys_cpu_present_mapis withMAX_APICSbits. and pre-enabled system some cpus apic id > 255.the variable after
phys_cpu_present_mapmay get corrupted.... siliently...
ffffffff828e8420Bphys_cpu_present_mapffffffff828e8440Bapic_verbosityffffffff828e8444Blocal_apic_timer_c2_okffffffff828e8448Bdisable_apicffffffff828e844cBx2apic_modeffffffff828e8450Bx2apic_disabledffffffff828e8454Bnum_processors
...Actually
phys_cpu_present_mapis referenced via apic id, instead index. we should useMAX_LOCAL_APICinsteadMAX_APICIS. but that is another header.So just let
MAX_APICSequal toMAX_LOCAL_APICat this point. esp for 64 bit will be 32768 in all cases.Signed-off-by Yinghai Lu <[email protected]>--- arch/x86/include/asm/mpspec_def.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)Index:
linux-2.6/arch/x86/include/asm/mpspec_def.h
===================================================================arch/x86/include/asm/mpspec_def.h +1
-5@@ -17,11 +17,7 @@# define MAX_MPC_ENTRY 1024# define MAX_APICS 256#else -# if NR_CPUS <=255 -# define MAX_APICS 255 -# else -# define MAX_APICS 32768 -# endif +# define MAX_APICS 32768#endif
Quoted 4 lines
arch/x86/include/asm/mpspec_def.h line 23
Quoted 1 line
arch/x86/include/asm/mpspec_def.h +0
-0/* Intel MP Floating Pointer Structure */ Please fix the real bug first: the lack of boundary checks when we set
phys_cpu_present_map!
real bug is that MAX_APICS and MAX_LOCAL_APIC using is messed up.
could be MAX_APICS is from 32bit, and MAX_LOCAL_APIC is from 64bit.
Quoted 4 lines
Then, once that bitmap op is not corrupting nearby variables silently but triggers a fail-safe logic instead (ignoring apics that go outside the supported range? printk-ing a warning?) can we think about upping the limit.
Using MAX_APICS and MAX_LOCAL_APIC at same time cause confusing.
We should just use MAX_LOCAL_APIC instead.
If MAX_APICS is not just for apic entries number, we don't need it. NR_CPUS or nr_cpu_ids will do the check for us.
Quoted 4 lines
But even with the limit upping, please show (in the changelog) a before/after 'size vmlinux' comparison, to make sure that this rather drastic change of the limit does not waste unreasonable amounts of memory.
about 4k for 64bit when NR_CPUS=255.
please check if you like following patch instead. or just keep MAX_APICS == MAX_LOCAL_APIC
[PATCH] x86: Remove MAX_APICS
Found one x2apic pre-enabled system, x2apic_mode suddenly get corrupted after register some cpus. when compiled CONFIG_NR_CPUS=255 instead of 512
It turns out that generic_processor_info() ==> phyid_set(apicid, phys_cpu_present_map) cause the problem.
phys_cpu_present_map is with MAX_APICS bits. and pre-enabled system some cpus apic id > 255.
the variable after phys_cpu_present_map may get corrupted.... siliently...
ffffffff828e8420 B phys_cpu_present_mapffffffff828e8440 B apic_verbosityffffffff828e8444 B local_apic_timer_c2_okffffffff828e8448 B disable_apicffffffff828e844c B x2apic_modeffffffff828e8450 B x2apic_disabledffffffff828e8454 B num_processors
...
Actually phys_cpu_present_map is referenced via apic id, instead index. We should use MAX_LOCAL_APIC instead MAX_APICS.
For 64 bit will be 32768 in all cases.
text data bss dec hex filename
21696943 4193748 12791808 38682499 24e3f83 vmlinux.after
21696943 4193748 12787712 38678403 24e2f83 vmlinux.before
bss will increase 4k bytes
no change for 32bit.
Finally could remove MAX_APCIS that causes confusing.
--- arch/x86/include/asm/mpspec.h | 29 +++++++++++------------------ arch/x86/include/asm/mpspec_def.h | 7 ------- arch/x86/kernel/acpi/boot.c | 6 +++--- arch/x86/kernel/apic/io_apic.c | 3 ++- arch/x86/platform/sfi/sfi.c | 4 ++-- arch/x86/platform/visws/visws_quirks.c | 2 +- 6 files changed, 19 insertions(+), 32 deletions(-)
arch/x86/include/asm/mpspec.h +11 -18
@@ -5,6 +5,7 @@#include <asm/mpspec_def.h> #include <asm/x86_init.h> +#include <asm/apicdef.h> extern int apic_version[];extern int pic_mode;
@@ -107,7 +108,7 @@ extern int mp_register_gsi(struct device int active_high_low);#endif /* CONFIG_ACPI */ -#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_APICS) +#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_LOCAL_APIC)struct physid_mask {unsigned long mask[PHYSID_ARRAY_SIZE ];
@@ -122,31 +123,31 @@ typedef struct physid_mask physid_mask_t test_and_set_bit(physid, (map).mask)#define physids_and (dst, src1, src2) \ - bitmap_and((dst).mask, (src1).mask, (src2).mask, MAX_APICS) + bitmap_and((dst).mask, (src1).mask, (src2).mask, MAX_LOCAL_APIC)#define physids_or (dst, src1, src2) \ - bitmap_or((dst).mask, (src1).mask, (src2).mask, MAX_APICS) + bitmap_or((dst).mask, (src1).mask, (src2).mask, MAX_LOCAL_APIC)#define physids_clear (map) \ - bitmap_zero((map).mask, MAX_APICS) + bitmap_zero((map).mask, MAX_LOCAL_APIC)#define physids_complement (dst, src) \ - bitmap_complement((dst).mask, (src).mask, MAX_APICS) + bitmap_complement((dst).mask, (src).mask, MAX_LOCAL_APIC)#define physids_empty (map) \ - bitmap_empty((map).mask, MAX_APICS) + bitmap_empty((map).mask, MAX_LOCAL_APIC)#define physids_equal (map1, map2) \ - bitmap_equal((map1).mask, (map2).mask, MAX_APICS) + bitmap_equal((map1).mask, (map2).mask, MAX_LOCAL_APIC)#define physids_weight (map) \ - bitmap_weight((map).mask, MAX_APICS) + bitmap_weight((map).mask, MAX_LOCAL_APIC)#define physids_shift_right (d, s, n) \ - bitmap_shift_right((d).mask, (s).mask, n, MAX_APICS) + bitmap_shift_right((d).mask, (s).mask, n, MAX_LOCAL_APIC)#define physids_shift_left (d, s, n) \ - bitmap_shift_left((d).mask, (s).mask, n, MAX_APICS) + bitmap_shift_left((d).mask, (s).mask, n, MAX_LOCAL_APIC)static inline unsigned long physids_coerce (physid_mask_t *map) {
@@ -159,14 +160,6 @@ static inline void physids_promote(unsig map->mask[0 ] = physids; } -/* Note: will create very large stack frames if physid_mask_t is big */ -#define physid_mask_of_physid (physid) \ - ({ \ - physid_mask_t __physid_mask = PHYSID_MASK_NONE; \ - physid_set(physid, __physid_mask); \ - __physid_mask; \ - }) -static inline void physid_set_mask_of_physid (int physid,physid_mask_t *map) {physids_clear (*map);
arch/x86/include/asm/mpspec_def.h +0 -7
@@ -15,13 +15,6 @@#ifdef CONFIG_X86_32 # define MAX_MPC_ENTRY 1024 -# define MAX_APICS 256 -#else -# if NR_CPUS <=255 -# define MAX_APICS 255 -# else -# define MAX_APICS 32768 -# endif #endif /* Intel MP Floating Pointer Structure */
arch/x86/kernel/acpi/boot.c +3 -3
@@ -903,13 +903,13 @@ static int __init acpi_parse_madt_lapic_register_lapic_address (acpi_lapic_addr); count =acpi_table_parse_madt (ACPI_MADT_TYPE_LOCAL_SAPIC , - acpi_parse_sapic,MAX_APICS ); + acpi_parse_sapic,MAX_LOCAL_APIC );if (!count) { x2count =acpi_table_parse_madt (ACPI_MADT_TYPE_LOCAL_X2APIC , - acpi_parse_x2apic,MAX_APICS ); + acpi_parse_x2apic,MAX_LOCAL_APIC ); count =acpi_table_parse_madt (ACPI_MADT_TYPE_LOCAL_APIC , - acpi_parse_lapic,MAX_APICS ); + acpi_parse_lapic,MAX_LOCAL_APIC ); }if (!count && !x2count) { printk(KERN_ERR PREFIX "No LAPIC entries present\n");
arch/x86/kernel/apic/io_apic.c +2 -1
@@ -4087,7 +4087,8 @@ void __init pre_init_apic_IRQ0(void)printk (KERN_INFO "Early APIC setup for system timer0\n" );#ifndef CONFIG_SMP - phys_cpu_present_map =physid_mask_of_physid (boot_cpu_physical_apicid); +physid_set_mask_of_physid (boot_cpu_physical_apicid, + &phys_cpu_present_map);#endif /* Make sure the irq descriptor is set up */ cfg =alloc_irq_and_cfg_at (0 ,0 );
arch/x86/platform/sfi/sfi.c +2 -2
@@ -37,9 +37,9 @@ static unsigned long sfi_lapic_addr __in/* All CPUs enumerated by SFI must be present and enabled */ static void __cpuinit mp_sfi_register_lapic (u8 id) { -if (MAX_APICS - id <=0 ) { +if (MAX_LOCAL_APIC - id <=0 ) {pr_warning ("Processor #%d invalid (max %d)\n" , - id,MAX_APICS ); + id,MAX_LOCAL_APIC );return ; }
arch/x86/platform/visws/visws_quirks.c +1 -1
@@ -171,7 +171,7 @@ static void __init MP_processor_info(str ver = m->apicver;if ((ver >=0x14 && m->apicid >=0xff ) || m->apicid >=0xf ) {printk (KERN_ERR "Processor #%d INVALID. (Max ID: %d).\n" , - m->apicid,MAX_APICS ); + m->apicid,MAX_LOCAL_APIC );return ; }
Quoted 6 lines · Yinghai Lu
Quoted 2 lines
Please fix the real bug first: the lack of boundary checks when we set
phys_cpu_present_map!real bug is that
MAX_APICSandMAX_LOCAL_APICusing is messed up.could be
MAX_APICSis from 32bit, andMAX_LOCAL_APICis from 64bit.
Indeed - nice patch!
Thanks,
Ingo
[tip:x86/apic] x86: Fix APIC ID sizing bug on larger systems, clean up MAX_APICS confusion
In reply to Yinghai LuCommit-ID: cb2ded37fd2e1039f96c8c892da024a8f033add5 Gitweb: http://git.kernel.org/tip/cb2ded37fd2e1039f96c8c892da024a8f033add5 Author: Yinghai Lu <[email protected]> AuthorDate: Tue, 4 Jan 2011 16:38:52 -0800 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 5 Jan 2011 14:09:23 +0100
x86: Fix APIC ID sizing bug on larger systems, clean up MAX_APICS confusion
Found one x2apic pre-enabled system, x2apic_mode suddenly get corrupted after register some cpus, when compiled CONFIG_NR_CPUS=255 instead of 512.
It turns out that generic_processor_info() ==> phyid_set(apicid, phys_cpu_present_map) causes the problem.
phys_cpu_present_map is sized by MAX_APICS bits, and pre-enabled system some cpus have an apic id > 255.
The variable after phys_cpu_present_map may get corrupted silently:
ffffffff828e8420 B phys_cpu_present_map
ffffffff828e8440 B apic_verbosity
ffffffff828e8444 B local_apic_timer_c2_ok
ffffffff828e8448 B disable_apic
ffffffff828e844c B x2apic_mode
ffffffff828e8450 B x2apic_disabled
ffffffff828e8454 B num_processors
...
Actually phys_cpu_present_map is referenced via apic id, instead index. We should use MAX_LOCAL_APIC instead MAX_APICS.
For 64-bit it will be 32768 in all cases. BSS will increase by 4k bytes on 64-bit:
text data bss dec filename 21696943 4193748 12787712 38678403 vmlinux.before 21696943 4193748 12791808 38682499 vmlinux.after
No change on 32bit.
Finally we can remove MAX_APCIS that was rather confusing.
LKML-Reference: <[email protected]>
--- arch/x86/include/asm/mpspec.h | 29 +++++++++++------------------ arch/x86/include/asm/mpspec_def.h | 7 ------- arch/x86/kernel/acpi/boot.c | 6 +++--- arch/x86/kernel/apic/io_apic.c | 3 ++- arch/x86/platform/sfi/sfi.c | 4 ++-- arch/x86/platform/visws/visws_quirks.c | 2 +- 6 files changed, 19 insertions(+), 32 deletions(-)
arch/x86/include/asm/mpspec.h +11 -18
@@ -5,6 +5,7 @@#include <asm/mpspec_def.h> #include <asm/x86_init.h> +#include <asm/apicdef.h> extern int apic_version[];extern int pic_mode;
@@ -107,7 +108,7 @@ extern int mp_register_gsi(struct device *dev, u32 gsi, int edge_level, int active_high_low);#endif /* CONFIG_ACPI */ -#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_APICS) +#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_LOCAL_APIC)struct physid_mask {unsigned long mask[PHYSID_ARRAY_SIZE ];
@@ -122,31 +123,31 @@ typedef struct physid_mask physid_mask_t; test_and_set_bit(physid, (map).mask)#define physids_and (dst, src1, src2) \ - bitmap_and((dst).mask, (src1).mask, (src2).mask, MAX_APICS) + bitmap_and((dst).mask, (src1).mask, (src2).mask, MAX_LOCAL_APIC)#define physids_or (dst, src1, src2) \ - bitmap_or((dst).mask, (src1).mask, (src2).mask, MAX_APICS) + bitmap_or((dst).mask, (src1).mask, (src2).mask, MAX_LOCAL_APIC)#define physids_clear (map) \ - bitmap_zero((map).mask, MAX_APICS) + bitmap_zero((map).mask, MAX_LOCAL_APIC)#define physids_complement (dst, src) \ - bitmap_complement((dst).mask, (src).mask, MAX_APICS) + bitmap_complement((dst).mask, (src).mask, MAX_LOCAL_APIC)#define physids_empty (map) \ - bitmap_empty((map).mask, MAX_APICS) + bitmap_empty((map).mask, MAX_LOCAL_APIC)#define physids_equal (map1, map2) \ - bitmap_equal((map1).mask, (map2).mask, MAX_APICS) + bitmap_equal((map1).mask, (map2).mask, MAX_LOCAL_APIC)#define physids_weight (map) \ - bitmap_weight((map).mask, MAX_APICS) + bitmap_weight((map).mask, MAX_LOCAL_APIC)#define physids_shift_right (d, s, n) \ - bitmap_shift_right((d).mask, (s).mask, n, MAX_APICS) + bitmap_shift_right((d).mask, (s).mask, n, MAX_LOCAL_APIC)#define physids_shift_left (d, s, n) \ - bitmap_shift_left((d).mask, (s).mask, n, MAX_APICS) + bitmap_shift_left((d).mask, (s).mask, n, MAX_LOCAL_APIC)static inline unsigned long physids_coerce (physid_mask_t *map) {
@@ -159,14 +160,6 @@ static inline void physids_promote(unsigned long physids, physid_mask_t *map) map->mask[0 ] = physids; } -/* Note: will create very large stack frames if physid_mask_t is big */ -#define physid_mask_of_physid (physid) \ - ({ \ - physid_mask_t __physid_mask = PHYSID_MASK_NONE; \ - physid_set(physid, __physid_mask); \ - __physid_mask; \ - }) -static inline void physid_set_mask_of_physid (int physid,physid_mask_t *map) {physids_clear (*map);
arch/x86/include/asm/mpspec_def.h +0 -7
@@ -15,13 +15,6 @@#ifdef CONFIG_X86_32 # define MAX_MPC_ENTRY 1024 -# define MAX_APICS 256 -#else -# if NR_CPUS <=255 -# define MAX_APICS 255 -# else -# define MAX_APICS 32768 -# endif #endif /* Intel MP Floating Pointer Structure */
arch/x86/kernel/acpi/boot.c +3 -3
@@ -915,13 +915,13 @@ static int __init acpi_parse_madt_lapic_entries(void)acpi_register_lapic_address (acpi_lapic_addr); count =acpi_table_parse_madt (ACPI_MADT_TYPE_LOCAL_SAPIC , - acpi_parse_sapic,MAX_APICS ); + acpi_parse_sapic,MAX_LOCAL_APIC );if (!count) { x2count =acpi_table_parse_madt (ACPI_MADT_TYPE_LOCAL_X2APIC , - acpi_parse_x2apic,MAX_APICS ); + acpi_parse_x2apic,MAX_LOCAL_APIC ); count =acpi_table_parse_madt (ACPI_MADT_TYPE_LOCAL_APIC , - acpi_parse_lapic,MAX_APICS ); + acpi_parse_lapic,MAX_LOCAL_APIC ); }if (!count && !x2count) { printk(KERN_ERR PREFIX "No LAPIC entries present\n");
arch/x86/kernel/apic/io_apic.c +2 -1
@@ -4109,7 +4109,8 @@ void __init pre_init_apic_IRQ0(void)printk (KERN_INFO "Early APIC setup for system timer0\n" );#ifndef CONFIG_SMP - phys_cpu_present_map =physid_mask_of_physid (boot_cpu_physical_apicid); +physid_set_mask_of_physid (boot_cpu_physical_apicid, + &phys_cpu_present_map);#endif /* Make sure the irq descriptor is set up */ cfg =alloc_irq_and_cfg_at (0 ,0 );
arch/x86/platform/sfi/sfi.c +2 -2
@@ -48,9 +48,9 @@ static void __init mp_sfi_register_lapic_address(unsigned long address)/* All CPUs enumerated by SFI must be present and enabled */ static void __cpuinit mp_sfi_register_lapic (u8 id) { -if (MAX_APICS - id <=0 ) { +if (MAX_LOCAL_APIC - id <=0 ) {pr_warning ("Processor #%d invalid (max %d)\n" , - id,MAX_APICS ); + id,MAX_LOCAL_APIC );return ; }
arch/x86/platform/visws/visws_quirks.c +1 -1
@@ -171,7 +171,7 @@ static void __init MP_processor_info(struct mpc_cpu *m) ver = m->apicver;if ((ver >=0x14 && m->apicid >=0xff ) || m->apicid >=0xf ) {printk (KERN_ERR "Processor #%d INVALID. (Max ID: %d).\n" , - m->apicid,MAX_APICS ); + m->apicid,MAX_LOCAL_APIC );return ; }