From f6b3ec238d12c8cc6cc71490c6e3127988460349 Mon Sep 17 00:00:00 2001 From: Badari Pulavarty Date: Fri, 6 Jan 2006 00:10:38 -0800 Subject: [PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing store Here is the patch to implement madvise(MADV_REMOVE) - which frees up a given range of pages & its associated backing store. Current implementation supports only shmfs/tmpfs and other filesystems return -ENOSYS. "Some app allocates large tmpfs files, then when some task quits and some client disconnect, some memory can be released. However the only way to release tmpfs-swap is to MADV_REMOVE". - Andrea Arcangeli Databases want to use this feature to drop a section of their bufferpool (shared memory segments) - without writing back to disk/swap space. This feature is also useful for supporting hot-plug memory on UML. Concerns raised by Andrew Morton: - "We have no plan for holepunching! If we _do_ have such a plan (or might in the future) then what would the API look like? I think sys_holepunch(fd, start, len), so we should start out with that." - Using madvise is very weird, because people will ask "why do I need to mmap my file before I can stick a hole in it?" - None of the other madvise operations call into the filesystem in this manner. A broad question is: is this capability an MM operation or a filesytem operation? truncate, for example, is a filesystem operation which sometimes has MM side-effects. madvise is an mm operation and with this patch, it gains FS side-effects, only they're really, really significant ones." Comments: - Andrea suggested the fs operation too but then it's more efficient to have it as a mm operation with fs side effects, because they don't immediatly know fd and physical offset of the range. It's possible to fixup in userland and to use the fs operation but it's more expensive, the vmas are already in the kernel and we can use them. Short term plan & Future Direction: - We seem to need this interface only for shmfs/tmpfs files in the short term. We have to add hooks into the filesystem for correctness and completeness. This is what this patch does. - In the future, plan is to support both fs and mmap apis also. This also involves (other) filesystem specific functions to be implemented. - Current patch doesn't support VM_NONLINEAR - which can be addressed in the future. Signed-off-by: Badari Pulavarty Cc: Hugh Dickins Cc: Andrea Arcangeli Cc: Michael Kerrisk Cc: Ulrich Drepper Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-frv/mman.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-frv') diff --git a/include/asm-frv/mman.h b/include/asm-frv/mman.h index c684720dfbdd..8af4a41c255e 100644 --- a/include/asm-frv/mman.h +++ b/include/asm-frv/mman.h @@ -35,6 +35,7 @@ #define MADV_SEQUENTIAL 0x2 /* read-ahead aggressively */ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ +#define MADV_REMOVE 0x5 /* remove these pages & resources */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS -- cgit v1.2.2 From d3cb487149bd706aa6aeb02042332a450978dc1c Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 6 Jan 2006 00:11:20 -0800 Subject: [PATCH] atomic_long_t & include/asm-generic/atomic.h V2 Several counters already have the need to use 64 atomic variables on 64 bit platforms (see mm_counter_t in sched.h). We have to do ugly ifdefs to fall back to 32 bit atomic on 32 bit platforms. The VM statistics patch that I am working on will also make more extensive use of atomic64. This patch introduces a new type atomic_long_t by providing definitions in asm-generic/atomic.h that works similar to the c "long" type. Its 32 bits on 32 bit platforms and 64 bits on 64 bit platforms. Also cleans up the determination of the mm_counter_t in sched.h. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-frv/atomic.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-frv') diff --git a/include/asm-frv/atomic.h b/include/asm-frv/atomic.h index f6539ff569c5..3f54fea2b051 100644 --- a/include/asm-frv/atomic.h +++ b/include/asm-frv/atomic.h @@ -426,4 +426,5 @@ extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new); }) #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) +#include #endif /* _ASM_ATOMIC_H */ -- cgit v1.2.2 From 5c40f7f373889930d176a515ec375b60a70b5b49 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 6 Jan 2006 00:11:43 -0800 Subject: [PATCH] FRV: Implement futex operations for FRV The attached patch implements futex operations for the FRV architecture. The operations are applicable to both MMU and no-MMU modes; though the EFAULT handling will be a little bit of wasted space on the latter. Signed-off-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-frv/futex.h | 42 +----------------------------------------- 1 file changed, 1 insertion(+), 41 deletions(-) (limited to 'include/asm-frv') diff --git a/include/asm-frv/futex.h b/include/asm-frv/futex.h index 9feff4ce1424..fca9d90e32c9 100644 --- a/include/asm-frv/futex.h +++ b/include/asm-frv/futex.h @@ -7,47 +7,7 @@ #include #include -static inline int -futex_atomic_op_inuser (int encoded_op, int __user *uaddr) -{ - int op = (encoded_op >> 28) & 7; - int cmp = (encoded_op >> 24) & 15; - int oparg = (encoded_op << 8) >> 20; - int cmparg = (encoded_op << 20) >> 20; - int oldval = 0, ret; - if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) - oparg = 1 << oparg; - - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) - return -EFAULT; - - inc_preempt_count(); - - switch (op) { - case FUTEX_OP_SET: - case FUTEX_OP_ADD: - case FUTEX_OP_OR: - case FUTEX_OP_ANDN: - case FUTEX_OP_XOR: - default: - ret = -ENOSYS; - } - - dec_preempt_count(); - - if (!ret) { - switch (cmp) { - case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; - case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; - case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; - case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; - case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; - case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; - default: ret = -ENOSYS; - } - } - return ret; -} +extern int futex_atomic_op_inuser(int encoded_op, int __user *uaddr); #endif #endif -- cgit v1.2.2 From fef2b580eb50281ae1d2413ab340f677f6722281 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 6 Jan 2006 00:11:45 -0800 Subject: [PATCH] frv: improve signal handling The attached patch improves the signal handling: (1) It makes do_signal() static as it isn't called from anywhere outside of the arch code. (2) It removes the regs argument to all the static functions within that file, using __frame instead (which is the same thing held in a global register). Signed-off-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-frv/signal.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/asm-frv') diff --git a/include/asm-frv/signal.h b/include/asm-frv/signal.h index d407bde57eca..67366894780f 100644 --- a/include/asm-frv/signal.h +++ b/include/asm-frv/signal.h @@ -151,7 +151,6 @@ typedef struct sigaltstack { size_t ss_size; } stack_t; -extern int do_signal(struct pt_regs *regs, sigset_t *oldset); #define ptrace_signal_deliver(regs, cookie) do { } while (0) #ifdef __KERNEL__ -- cgit v1.2.2