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* Merge branch 'x86-atomic-for-linus' of ↵Linus Torvalds2012-03-22
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/atomic changes from Ingo Molnar. * 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: atomic64 assembly improvements x86: Adjust asm constraints in atomic64 wrappers
| * x86: atomic64 assembly improvementsJan Beulich2012-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the "xchg" implementation, %ebx and %ecx don't need to be copied into %eax and %edx respectively (this is only necessary when desiring to only read the stored value). In the "add_unless" implementation, swapping the use of %ecx and %esi for passing arguments allows %esi to become an input only (i.e. permitting the register to be re-used to address the same object without reload). In "{add,sub}_return", doing the initial read64 through the passed in %ecx decreases a register dependency. In "inc_not_zero", a branch can be eliminated by or-ing together the two halves of the current (64-bit) value, and code size can be further reduced by adjusting the arithmetic slightly. v2: Undo the folding of "xchg" and "set". Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F19A2BC020000780006E0DC@nat28.tlf.novell.com Cc: Luca Barbieri <luca@luca-barbieri.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86: Adjust asm constraints in atomic64 wrappersJan Beulich2012-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Eric pointed out overly restrictive constraints in atomic64_set(), but there are issues throughout the file. In the cited case, %ebx and %ecx are inputs only (don't get changed by either of the two low level implementations). This was also the case elsewhere. Further in many cases early-clobber indicators were missing. Finally, the previous implementation rolled a custom alternative instruction macro from scratch, rather than using alternative_call() (which was introduced with the commit that the description of the change in question actually refers to). Adjusting has the benefit of not hiding referenced symbols from the compiler, which however requires them to be declared not just in the exporting source file (which, as a desirable side effect, in turn allows that exporting file to become a real 5-line stub). This patch does not eliminate the overly restrictive memory clobbers, however: Doing so would occasionally make the compiler set up a second register for accessing the memory object (to satisfy the added "m" constraint), and it's not clear which of the two non-optimal alternatives is better. v2: Re-do the declaration and exporting of the internal symbols. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F19A2A5020000780006E0D9@nat28.tlf.novell.com Cc: Luca Barbieri <luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2012-03-22
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/asm changes from Ingo Molnar * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Include probe_roms.h in probe_roms.c x86/32: Print control and debug registers for kerenel context x86: Tighten dependencies of CPU_SUP_*_32 x86/numa: Improve internode cache alignment x86: Fix the NMI nesting comments x86-64: Improve insn scheduling in SAVE_ARGS_IRQ x86-64: Fix CFI annotations for NMI nesting code bitops: Add missing parentheses to new get_order macro bitops: Optimise get_order() bitops: Adjust the comment on get_order() to describe the size==0 case x86/spinlocks: Eliminate TICKET_MASK x86-64: Handle byte-wise tail copying in memcpy() without a loop x86-64: Fix memcpy() to support sizes of 4Gb and above x86-64: Fix memset() to support sizes of 4Gb and above x86-64: Slightly shorten copy_page()
| * | x86: Include probe_roms.h in probe_roms.cJan Beulich2012-03-08
| | | | | | | | | | | | | | | | | | | | | | | | ... to ensure that declarations and definitions are in sync. Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F5888F902000078000770F1@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | x86/32: Print control and debug registers for kerenel contextJan Beulich2012-03-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While for a user mode register dump it may be reasonable to skip those (albeit x86-64 doesn't do so), for kernel mode dumps these should be printed to make sure all information possibly necessary for analysis is available. Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F58889202000078000770E7@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | x86: Tighten dependencies of CPU_SUP_*_32Jan Beulich2012-03-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building in support for either of these CPUs is pointless when e.g. M686 was selected (since such a kernel would use cmov instructions, which aren't available on these older CPUs). Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F58875A02000078000770E0@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | x86/numa: Improve internode cache alignmentAlex Shi2012-03-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently cache alignment among nodes in the kernel is still 128 bytes on x86 NUMA machines - we got that X86_INTERNODE_CACHE_SHIFT default from old P4 processors. But now most modern x86 CPUs use the same size: 64 bytes from L1 to last level L3. so let's remove the incorrect setting, and directly use the L1 cache size to do SMP cache line alignment. This patch saves some memory space on kernel data, and it also improves the cache locality of kernel data. The System.map is quite different with/without this change: before patch after patch ... 000000000000b000 d tlb_vector_| 000000000000b000 d tlb_vector 000000000000b080 d cpu_loops_p| 000000000000b040 d cpu_loops_ ... Signed-off-by: Alex Shi <alex.shi@intel.com> Cc: asit.k.mallick@intel.com Link: http://lkml.kernel.org/r/1330774047-18597-1-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'tip/x86/urgent' of ↵Ingo Molnar2012-02-28
| |\ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into x86/asm
| | * | x86: Fix the NMI nesting commentsSteven Rostedt2012-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the comments for the nesting NMI algorithm were stale and had some references to some prototypes that were first tried. I also updated the comments to be a little easier to understand the flow of the code. It definitely needs the documentation. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * | x86-64: Fix CFI annotations for NMI nesting codeJan Beulich2012-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The saving and restoring of %rdx wasn't annotated at all, and the jumping over sections where state gets partly restored wasn't handled either. Further, by folding the pushing of the previous frame in repeat_nmi into that which so far was immediately preceding restart_nmi (after moving the restore of %rdx ahead of that, since it doesn't get used anymore when pushing prior frames), annotations of the replicated frame creations can be made consistent too. v2: Fully fold repeat_nmi into the normal code flow (adding a single redundant instruction to the "normal" code path), thus retaining the special protection of all instructions between repeat_nmi and end_repeat_nmi. Link: http://lkml.kernel.org/r/4F478B630200007800074A31@nat28.tlf.novell.com Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | Merge branch 'linus' into x86/asmIngo Molnar2012-02-28
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | Sync up the latest NMI fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86-64: Improve insn scheduling in SAVE_ARGS_IRQJan Beulich2012-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In one case, use an address register that was computed earlier (and with a simpler instruction), thus reducing the risk of a stall. In the second case, eliminate a branch by using a conditional move (as is already done in call_softirq and xen_do_hypervisor_callback). Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F4788A50200007800074A26@nat28.tlf.novell.com Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | | | bitops: Add missing parentheses to new get_order macroJoerg Roedel2012-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new get_order macro introcuded in commit d66acc39c7cee323733c8503b9de1821a56dff7e does not use parentheses around all uses of the parameter n. This causes new compile warnings, for example in the amd_iommu_init.c function: drivers/iommu/amd_iommu_init.c:561:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] drivers/iommu/amd_iommu_init.c:561:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] Fix those warnings by adding the missing parentheses. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Link: http://lkml.kernel.org/r/1330088295-28732-1-git-send-email-joerg.roedel@amd.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | | | bitops: Optimise get_order()David Howells2012-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Optimise get_order() to use bit scanning instructions if such exist rather than a loop. Also, make it possible to use get_order() in static initialisations too by building it on top of ilog2() in the constant parameter case. This has been tested for i386 and x86_64 using the following userspace program, and for FRV by making appropriate substitutions for fls() and fls64(). It will abort if the case for get_order() deviates from the original except for the order of 0, for which get_order() produces an undefined result. This program tests both dynamic and static parameters. #include <stdlib.h> #include <stdio.h> #ifdef __x86_64__ #define BITS_PER_LONG 64 #else #define BITS_PER_LONG 32 #endif #define PAGE_SHIFT 12 typedef unsigned long long __u64, u64; typedef unsigned int __u32, u32; #define noinline __attribute__((noinline)) static inline int fls(int x) { int bitpos = -1; asm("bsrl %1,%0" : "+r" (bitpos) : "rm" (x)); return bitpos + 1; } static __always_inline int fls64(__u64 x) { #if BITS_PER_LONG == 64 long bitpos = -1; asm("bsrq %1,%0" : "+r" (bitpos) : "rm" (x)); return bitpos + 1; #else __u32 h = x >> 32, l = x; int bitpos = -1; asm("bsrl %1,%0 \n" "subl %2,%0 \n" "bsrl %3,%0 \n" : "+r" (bitpos) : "rm" (l), "i"(32), "rm" (h)); return bitpos + 33; #endif } static inline __attribute__((const)) int __ilog2_u32(u32 n) { return fls(n) - 1; } static inline __attribute__((const)) int __ilog2_u64(u64 n) { return fls64(n) - 1; } extern __attribute__((const, noreturn)) int ____ilog2_NaN(void); #define ilog2(n) \ ( \ __builtin_constant_p(n) ? ( \ (n) < 1 ? ____ilog2_NaN() : \ (n) & (1ULL << 63) ? 63 : \ (n) & (1ULL << 62) ? 62 : \ (n) & (1ULL << 61) ? 61 : \ (n) & (1ULL << 60) ? 60 : \ (n) & (1ULL << 59) ? 59 : \ (n) & (1ULL << 58) ? 58 : \ (n) & (1ULL << 57) ? 57 : \ (n) & (1ULL << 56) ? 56 : \ (n) & (1ULL << 55) ? 55 : \ (n) & (1ULL << 54) ? 54 : \ (n) & (1ULL << 53) ? 53 : \ (n) & (1ULL << 52) ? 52 : \ (n) & (1ULL << 51) ? 51 : \ (n) & (1ULL << 50) ? 50 : \ (n) & (1ULL << 49) ? 49 : \ (n) & (1ULL << 48) ? 48 : \ (n) & (1ULL << 47) ? 47 : \ (n) & (1ULL << 46) ? 46 : \ (n) & (1ULL << 45) ? 45 : \ (n) & (1ULL << 44) ? 44 : \ (n) & (1ULL << 43) ? 43 : \ (n) & (1ULL << 42) ? 42 : \ (n) & (1ULL << 41) ? 41 : \ (n) & (1ULL << 40) ? 40 : \ (n) & (1ULL << 39) ? 39 : \ (n) & (1ULL << 38) ? 38 : \ (n) & (1ULL << 37) ? 37 : \ (n) & (1ULL << 36) ? 36 : \ (n) & (1ULL << 35) ? 35 : \ (n) & (1ULL << 34) ? 34 : \ (n) & (1ULL << 33) ? 33 : \ (n) & (1ULL << 32) ? 32 : \ (n) & (1ULL << 31) ? 31 : \ (n) & (1ULL << 30) ? 30 : \ (n) & (1ULL << 29) ? 29 : \ (n) & (1ULL << 28) ? 28 : \ (n) & (1ULL << 27) ? 27 : \ (n) & (1ULL << 26) ? 26 : \ (n) & (1ULL << 25) ? 25 : \ (n) & (1ULL << 24) ? 24 : \ (n) & (1ULL << 23) ? 23 : \ (n) & (1ULL << 22) ? 22 : \ (n) & (1ULL << 21) ? 21 : \ (n) & (1ULL << 20) ? 20 : \ (n) & (1ULL << 19) ? 19 : \ (n) & (1ULL << 18) ? 18 : \ (n) & (1ULL << 17) ? 17 : \ (n) & (1ULL << 16) ? 16 : \ (n) & (1ULL << 15) ? 15 : \ (n) & (1ULL << 14) ? 14 : \ (n) & (1ULL << 13) ? 13 : \ (n) & (1ULL << 12) ? 12 : \ (n) & (1ULL << 11) ? 11 : \ (n) & (1ULL << 10) ? 10 : \ (n) & (1ULL << 9) ? 9 : \ (n) & (1ULL << 8) ? 8 : \ (n) & (1ULL << 7) ? 7 : \ (n) & (1ULL << 6) ? 6 : \ (n) & (1ULL << 5) ? 5 : \ (n) & (1ULL << 4) ? 4 : \ (n) & (1ULL << 3) ? 3 : \ (n) & (1ULL << 2) ? 2 : \ (n) & (1ULL << 1) ? 1 : \ (n) & (1ULL << 0) ? 0 : \ ____ilog2_NaN() \ ) : \ (sizeof(n) <= 4) ? \ __ilog2_u32(n) : \ __ilog2_u64(n) \ ) static noinline __attribute__((const)) int old_get_order(unsigned long size) { int order; size = (size - 1) >> (PAGE_SHIFT - 1); order = -1; do { size >>= 1; order++; } while (size); return order; } static noinline __attribute__((const)) int __get_order(unsigned long size) { int order; size--; size >>= PAGE_SHIFT; #if BITS_PER_LONG == 32 order = fls(size); #else order = fls64(size); #endif return order; } #define get_order(n) \ ( \ __builtin_constant_p(n) ? ( \ (n == 0UL) ? BITS_PER_LONG - PAGE_SHIFT : \ ((n < (1UL << PAGE_SHIFT)) ? 0 : \ ilog2((n) - 1) - PAGE_SHIFT + 1) \ ) : \ __get_order(n) \ ) #define order(N) \ { (1UL << N) - 1, get_order((1UL << N) - 1) }, \ { (1UL << N), get_order((1UL << N)) }, \ { (1UL << N) + 1, get_order((1UL << N) + 1) } struct order { unsigned long n, order; }; static const struct order order_table[] = { order(0), order(1), order(2), order(3), order(4), order(5), order(6), order(7), order(8), order(9), order(10), order(11), order(12), order(13), order(14), order(15), order(16), order(17), order(18), order(19), order(20), order(21), order(22), order(23), order(24), order(25), order(26), order(27), order(28), order(29), order(30), order(31), #if BITS_PER_LONG == 64 order(32), order(33), order(34), order(35), #endif { 0x2929 } }; void check(int loop, unsigned long n) { unsigned long old, new; printf("[%2d]: %09lx | ", loop, n); old = old_get_order(n); new = get_order(n); printf("%3ld, %3ld\n", old, new); if (n != 0 && old != new) abort(); } int main(int argc, char **argv) { const struct order *p; unsigned long n; int loop; for (loop = 0; loop <= BITS_PER_LONG - 1; loop++) { n = 1UL << loop; check(loop, n - 1); check(loop, n); check(loop, n + 1); } for (p = order_table; p->n != 0x2929; p++) { unsigned long old, new; old = old_get_order(p->n); new = p->order; printf("%09lx\t%3ld, %3ld\n", p->n, old, new); if (p->n != 0 && old != new) abort(); } return 0; } Disassembling the x86_64 version of the above code shows: 0000000000400510 <old_get_order>: 400510: 48 83 ef 01 sub $0x1,%rdi 400514: b8 ff ff ff ff mov $0xffffffff,%eax 400519: 48 c1 ef 0b shr $0xb,%rdi 40051d: 0f 1f 00 nopl (%rax) 400520: 83 c0 01 add $0x1,%eax 400523: 48 d1 ef shr %rdi 400526: 75 f8 jne 400520 <old_get_order+0x10> 400528: f3 c3 repz retq 40052a: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 0000000000400530 <__get_order>: 400530: 48 83 ef 01 sub $0x1,%rdi 400534: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax 40053b: 48 c1 ef 0c shr $0xc,%rdi 40053f: 48 0f bd c7 bsr %rdi,%rax 400543: 83 c0 01 add $0x1,%eax 400546: c3 retq 400547: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 40054e: 00 00 As can be seen, the new __get_order() function is simpler than the old_get_order() function. Signed-off-by: David Howells <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120220223928.16199.29548.stgit@warthog.procyon.org.uk Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | | bitops: Adjust the comment on get_order() to describe the size==0 caseDavid Howells2012-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adjust the comment on get_order() to note that the result of passing a size of 0 results in an undefined value. Signed-off-by: David Howells <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120220223917.16199.9416.stgit@warthog.procyon.org.uk Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | | x86/spinlocks: Eliminate TICKET_MASKJan Beulich2012-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The definition of it being questionable already (unnecessarily including a cast), and it being used in a single place that can be written shorter without it, remove this #define. Along the same lines, simplify __ticket_spin_is_locked()'s main expression, which was the more convoluted way because of needs that went away with the recent type changes by Jeremy. This is pure cleanup, no functional change intended. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F2C06020200007800071066@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86-64: Handle byte-wise tail copying in memcpy() without a loopJan Beulich2012-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While hard to measure, reducing the number of possibly/likely mis-predicted branches can generally be expected to be slightly better. Other than apparent at the first glance, this also doesn't grow the function size (the alignment gap to the next function just gets smaller). Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/4F218584020000780006F422@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86-64: Fix memcpy() to support sizes of 4Gb and aboveJan Beulich2012-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While currently there doesn't appear to be any reachable in-tree case where such large memory blocks may be passed to memcpy(), we already had hit the problem in our Xen kernels. Just like done recently for mmeset(), rather than working around it, prevent others from falling into the same trap by fixing this long standing limitation. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/4F21846F020000780006F3FA@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86-64: Fix memset() to support sizes of 4Gb and aboveJan Beulich2012-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While currently there doesn't appear to be any reachable in-tree case where such large memory blocks may be passed to memset() (alloc_bootmem() being the primary non-reachable one, as it gets called with suitably large sizes in FLATMEM configurations), we have recently hit the problem a second time in our Xen kernels. Rather than working around it a second time, prevent others from falling into the same trap by fixing this long standing limitation. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/4F05D992020000780006AA09@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86-64: Slightly shorten copy_page()Jan Beulich2012-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | %r13 got saved and restored without ever getting touched, so there's no need to do so. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/4F05D9F9020000780006AA0D@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds2012-03-22
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first batch of patches from Andrew Morton: "A few misc things and all the MM queue" * emailed from Andrew Morton <akpm@linux-foundation.org>: (92 commits) memcg: avoid THP split in task migration thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE memcg: clean up existing move charge code mm/memcontrol.c: remove unnecessary 'break' in mem_cgroup_read() mm/memcontrol.c: remove redundant BUG_ON() in mem_cgroup_usage_unregister_event() mm/memcontrol.c: s/stealed/stolen/ memcg: fix performance of mem_cgroup_begin_update_page_stat() memcg: remove PCG_FILE_MAPPED memcg: use new logic for page stat accounting memcg: remove PCG_MOVE_LOCK flag from page_cgroup memcg: simplify move_account() check memcg: remove EXPORT_SYMBOL(mem_cgroup_update_page_stat) memcg: kill dead prev_priority stubs memcg: remove PCG_CACHE page_cgroup flag memcg: let css_get_next() rely upon rcu_read_lock() cgroup: revert ss_id_lock to spinlock idr: make idr_get_next() good for rcu_read_lock() memcg: remove unnecessary thp check in page stat accounting memcg: remove redundant returns memcg: enum lru_list lru ...
| * | | | | memcg: avoid THP split in task migrationNaoya Horiguchi2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we can't do task migration among memory cgroups without THP split, which means processes heavily using THP experience large overhead in task migration. This patch introduces the code for moving charge of THP and makes THP more valuable. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGENaoya Horiguchi2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These macros will be used in a later patch, where all usages are expected to be optimized away without #ifdef CONFIG_TRANSPARENT_HUGEPAGE. But to detect unexpected usages, we convert the existing BUG() to BUILD_BUG(). [akpm@linux-foundation.org: fix build in mm/pgtable-generic.c] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: clean up existing move charge codeNaoya Horiguchi2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Replace lengthy function name is_target_pte_for_mc() with a shorter one in order to avoid ugly line breaks. - explicitly use MC_TARGET_* instead of simply using integers. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Hillf Danton <dhillf@gmail.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm/memcontrol.c: remove unnecessary 'break' in mem_cgroup_read()Jeff Liu2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm/memcontrol.c: remove redundant BUG_ON() in ↵Anton Vorontsov2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mem_cgroup_usage_unregister_event() In the following code: if (type == _MEM) thresholds = &memcg->thresholds; else if (type == _MEMSWAP) thresholds = &memcg->memsw_thresholds; else BUG(); BUG_ON(!thresholds); The BUG_ON() seems redundant. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm/memcontrol.c: s/stealed/stolen/Andrew Morton2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A grammatical fix. Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: fix performance of mem_cgroup_begin_update_page_stat()KAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mem_cgroup_begin_update_page_stat() should be very fast because it's called very frequently. Now, it needs to look up page_cgroup and its memcg....this is slow. This patch adds a global variable to check "any memcg is moving or not". With this, the caller doesn't need to visit page_cgroup and memcg. Here is a test result. A test program makes page faults onto a file, MAP_SHARED and makes each page's page_mapcount(page) > 1, and free the range by madvise() and page fault again. This program causes 26214400 times of page fault onto a file(size was 1G.) and shows shows the cost of mem_cgroup_begin_update_page_stat(). Before this patch for mem_cgroup_begin_update_page_stat() [kamezawa@bluextal test]$ time ./mmap 1G real 0m21.765s user 0m5.999s sys 0m15.434s 27.46% mmap mmap [.] reader 21.15% mmap [kernel.kallsyms] [k] page_fault 9.17% mmap [kernel.kallsyms] [k] filemap_fault 2.96% mmap [kernel.kallsyms] [k] __do_fault 2.83% mmap [kernel.kallsyms] [k] __mem_cgroup_begin_update_page_stat After this patch [root@bluextal test]# time ./mmap 1G real 0m21.373s user 0m6.113s sys 0m15.016s In usual path, calls to __mem_cgroup_begin_update_page_stat() goes away. Note: we may be able to remove this optimization in future if we can get pointer to memcg directly from struct page. [akpm@linux-foundation.org: don't return a void] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Greg Thelen <gthelen@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: remove PCG_FILE_MAPPEDKAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the new lock scheme for updating memcg's page stat, we don't need a flag PCG_FILE_MAPPED which was duplicated information of page_mapped(). [hughd@google.com: cosmetic fix] [hughd@google.com: add comment to MEM_CGROUP_CHARGE_TYPE_MAPPED case in __mem_cgroup_uncharge_common()] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Greg Thelen <gthelen@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: use new logic for page stat accountingKAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, page-stat-per-memcg is recorded into per page_cgroup flag by duplicating page's status into the flag. The reason is that memcg has a feature to move a page from a group to another group and we have race between "move" and "page stat accounting", Under current logic, assume CPU-A and CPU-B. CPU-A does "move" and CPU-B does "page stat accounting". When CPU-A goes 1st, CPU-A CPU-B update "struct page" info. move_lock_mem_cgroup(memcg) see pc->flags copy page stat to new group overwrite pc->mem_cgroup. move_unlock_mem_cgroup(memcg) move_lock_mem_cgroup(mem) set pc->flags update page stat accounting move_unlock_mem_cgroup(mem) stat accounting is guarded by move_lock_mem_cgroup() and "move" logic (CPU-A) doesn't see changes in "struct page" information. But it's costly to have the same information both in 'struct page' and 'struct page_cgroup'. And, there is a potential problem. For example, assume we have PG_dirty accounting in memcg. PG_..is a flag for struct page. PCG_ is a flag for struct page_cgroup. (This is just an example. The same problem can be found in any kind of page stat accounting.) CPU-A CPU-B TestSet PG_dirty (delay) TestClear PG_dirty if (TestClear(PCG_dirty)) memcg->nr_dirty-- if (TestSet(PCG_dirty)) memcg->nr_dirty++ Here, memcg->nr_dirty = +1, this is wrong. This race was reported by Greg Thelen <gthelen@google.com>. Now, only FILE_MAPPED is supported but fortunately, it's serialized by page table lock and this is not real bug, _now_, If this potential problem is caused by having duplicated information in struct page and struct page_cgroup, we may be able to fix this by using original 'struct page' information. But we'll have a problem in "move account" Assume we use only PG_dirty. CPU-A CPU-B TestSet PG_dirty (delay) move_lock_mem_cgroup() if (PageDirty(page)) new_memcg->nr_dirty++ pc->mem_cgroup = new_memcg; move_unlock_mem_cgroup() move_lock_mem_cgroup() memcg = pc->mem_cgroup new_memcg->nr_dirty++ accounting information may be double-counted. This was original reason to have PCG_xxx flags but it seems PCG_xxx has another problem. I think we need a bigger lock as move_lock_mem_cgroup(page) TestSetPageDirty(page) update page stats (without any checks) move_unlock_mem_cgroup(page) This fixes both of problems and we don't have to duplicate page flag into page_cgroup. Please note: move_lock_mem_cgroup() is held only when there are possibility of "account move" under the system. So, in most path, status update will go without atomic locks. This patch introduces mem_cgroup_begin_update_page_stat() and mem_cgroup_end_update_page_stat() both should be called at modifying 'struct page' information if memcg takes care of it. as mem_cgroup_begin_update_page_stat() modify page information mem_cgroup_update_page_stat() => never check any 'struct page' info, just update counters. mem_cgroup_end_update_page_stat(). This patch is slow because we need to call begin_update_page_stat()/ end_update_page_stat() regardless of accounted will be changed or not. A following patch adds an easy optimization and reduces the cost. [akpm@linux-foundation.org: s/lock/locked/] [hughd@google.com: fix deadlock by avoiding stat lock when anon] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Greg Thelen <gthelen@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: remove PCG_MOVE_LOCK flag from page_cgroupKAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PCG_MOVE_LOCK is used for bit spinlock to avoid race between overwriting pc->mem_cgroup and page statistics accounting per memcg. This lock helps to avoid the race but the race is very rare because moving tasks between cgroup is not a usual job. So, it seems using 1bit per page is too costly. This patch changes this lock as per-memcg spinlock and removes PCG_MOVE_LOCK. If smaller lock is required, we'll be able to add some hashes but I'd like to start from this. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: simplify move_account() checkKAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In memcg, for avoiding take-lock-irq-off at accessing page_cgroup, a logic, flag + rcu_read_lock(), is used. This works as following CPU-A CPU-B rcu_read_lock() set flag if(flag is set) take heavy lock do job. synchronize_rcu() rcu_read_unlock() take heavy lock. In recent discussion, it's argued that using per-cpu value for this flag just complicates the code because 'set flag' is very rare. This patch changes 'flag' implementation from percpu to atomic_t. This will be much simpler. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: remove EXPORT_SYMBOL(mem_cgroup_update_page_stat)KAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As described in the log, I guess EXPORT was for preparing dirty accounting. But _now_, we don't need to export this. Remove this for now. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: kill dead prev_priority stubsKonstantin Khlebnikov2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code was removed in 25edde033291 ("vmscan: kill prev_priority completely") Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: remove PCG_CACHE page_cgroup flagKAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We record 'the page is cache' with the PCG_CACHE bit in page_cgroup. Here, "CACHE" means anonymous user pages (and SwapCache). This doesn't include shmem. Considering callers, at charge/uncharge, the caller should know what the page is and we don't need to record it by using one bit per page. This patch removes PCG_CACHE bit and make callers of mem_cgroup_charge_statistics() to specify what the page is. About page migration: Mapping of the used page is not touched during migra tion (see page_remove_rmap) so we can rely on it and push the correct charge type down to __mem_cgroup_uncharge_common from end_migration for unused page. The force flag was misleading was abused for skipping the needless page_mapped() / PageCgroupMigration() check, as we know the unused page is no longer mapped and cleared the migration flag just a few lines up. But doing the checks is no biggie and it's not worth adding another flag just to skip them. [akpm@linux-foundation.org: checkpatch fixes] [hughd@google.com: fix PageAnon uncharging] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Cc: Ying Han <yinghan@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: let css_get_next() rely upon rcu_read_lock()Hugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove lock and unlock around css_get_next()'s call to idr_get_next(). memcg iterators (only users of css_get_next) already did rcu_read_lock(), and its comment demands that; but add a WARN_ON_ONCE to make sure of it. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | cgroup: revert ss_id_lock to spinlockHugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c1e2ee2dc436 ("memcg: replace ss->id_lock with a rwlock") has now been seen to cause the unfair behavior we should have expected from converting a spinlock to an rwlock: softlockup in cgroup_mkdir(), whose get_new_cssid() is waiting for the wlock, while there are 19 tasks using the rlock in css_get_next() to get on with their memcg workload (in an artificial test, admittedly). Yet lib/idr.c was made suitable for RCU way back: revert that commit, restoring ss->id_lock to a spinlock. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | idr: make idr_get_next() good for rcu_read_lock()Hugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make one small adjustment to idr_get_next(): take the height from the top layer (stable under RCU) instead of from the root (unprotected by RCU), as idr_find() does: so that it can be used with RCU locking. Copied comment on RCU locking from idr_find(). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: remove unnecessary thp check in page stat accountingKAMEZAWA Hiroyuki2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e94c8a9cbce1 ("memcg: make mem_cgroup_split_huge_fixup() more efficient") removed move_lock_page_cgroup(). So we do not have to check PageTransHuge in mem_cgroup_update_page_stat() and fallback into the locked accounting because both move_account() and thp split are done with compound_lock so they cannot race. The race between update vs. move is protected by mem_cgroup_stealed. PageTransHuge pages shouldn't appear in this code path currently because we are tracking only file pages at the moment but later we are planning to track also other pages (e.g. mlocked ones). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Acked-by: Ying Han<yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: remove redundant returnsHugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove redundant returns from ends of functions, and one blank line. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: enum lru_list lruHugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly we use "enum lru_list lru": change those few "l"s to "lru"s. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: lru_size instead of MEM_CGROUP_ZSTATHugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I never understood why we need a MEM_CGROUP_ZSTAT(mz, idx) macro to obscure the LRU counts. For easier searching? So call it lru_size rather than bare count (lru_length sounds better, but would be wrong, since each huge page raises lru_size hugely). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: replace mem and mem_cont stragglersHugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace mem and mem_cont stragglers in memcontrol.c by memcg. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | memcg: replace MEM_CONT by MEM_RES_CTLRHugh Dickins2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct an #endif comment in memcontrol.h from MEM_CONT to MEM_RES_CTLR. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | swap: don't do discard if no discard option addedShaohua Li2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When swapon() was not passed the SWAP_FLAG_DISCARD option, sys_swapon() will still perform a discard operation. This can cause problems if discard is slow or buggy. Reverse the order of the check so that a discard operation is performed only if the sys_swapon() caller is attempting to enable discard. Signed-off-by: Shaohua Li <shli@fusionio.com> Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de> Tested-by: Holger Kiehl <Holger.Kiehl@dwd.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mm: forbid lumpy-reclaim in shrink_active_list()Konstantin Khlebnikov2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reset the reclaim mode in shrink_active_list() to RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC. (sync/async sign is used only in shrink_page_list and does not affect shrink_active_list) Currenly shrink_active_list() sometimes works in lumpy-reclaim mode, if RECLAIM_MODE_LUMPYRECLAIM is left over from an earlier shrink_inactive_list(). Meanwhile, in age_active_anon() sc->reclaim_mode is totally zero. So the current behavior is too complex and confusing, and this looks like bug. In general, shrink_active_list() populates the inactive list for the next shrink_inactive_list(). Lumpy shring_inactive_list() isolates pages around the chosen one from both the active and inactive lists. So, there is no reason for lumpy isolation in shrink_active_list(). See also: https://lkml.org/lkml/2012/3/15/583 Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Proposed-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | mmap.c: fix comment for __insert_vm_struct()Kautuk Consul2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment above __insert_vm_struct seems to suggest that this function is also going to link the VMA with the anon_vma, but this is not true. This function only links the VMA to the mm->mm_rb tree and the mm->mmap linked list. [akpm@linux-foundation.org: improve comment layout and text] Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | numa_emulation: fix cpumask_of_node()Andrea Arcangeli2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without this fix the cpumask_of_node() for a fake=numa=2 is: cpumask 0 ff cpumask 1 ff with the fix it's correct and it's set to: cpumask 0 55 cpumask 1 aa Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Johannes Weiner <jweiner@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | page_alloc: remove unused find_zone_movable_pfns_for_nodes() argumentKautuk Consul2012-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_zone_movable_pfns_for_nodes() does not use its argument. Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>