diff options
Diffstat (limited to 'package/mpatrol/mpatrol-unwindcache.patch')
| -rw-r--r-- | package/mpatrol/mpatrol-unwindcache.patch | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/package/mpatrol/mpatrol-unwindcache.patch b/package/mpatrol/mpatrol-unwindcache.patch new file mode 100644 index 000000000..3234d5c81 --- /dev/null +++ b/package/mpatrol/mpatrol-unwindcache.patch @@ -0,0 +1,208 @@ +Patch to improve MIPS call stack unwind performance by caching the results +of code reading. +by Dan Howell <dahowell@directv.com> + +diff -urN mpatrol-uclibc/src/stack.c mpatrol-unwindcache/src/stack.c +--- mpatrol-uclibc/src/stack.c 2006-06-22 15:39:04.000000000 -0700 ++++ mpatrol-unwindcache/src/stack.c 2006-06-22 15:42:20.000000000 -0700 +@@ -68,6 +68,7 @@ + #define ucontext asm_ucontext + #include <asm/ucontext.h> + #undef ucontext ++#include "heap.h" + #endif /* ARCH */ + #endif /* SYSTEM */ + #endif /* TARGET */ +@@ -280,6 +281,136 @@ + + #if !MP_BUILTINSTACK_SUPPORT && !MP_LIBRARYSTACK_SUPPORT + #if TARGET == TARGET_UNIX && ARCH == ARCH_MIPS ++/* Set up a tree to cache the results of code searching to determine the ++ location of the return address for each code point encountered. */ ++ ++/* An unwind node belongs to a binary search tree of nodes, ordered by ++ * code address, and contains call stack unwinding details for a given ++ * code address. An internal index node stores details of a single memory ++ * block allocated for unwind node slots. ++ */ ++typedef union unwindnode ++{ ++ struct ++ { ++ treenode node; /* internal tree node */ ++ void *block; /* pointer to block of memory */ ++ size_t size; /* size of block of memory */ ++ } ++ index; ++ struct ++ { ++ treenode node; /* tree node */ ++ long p; /* return address offset in the stack */ ++ long m; /* frame pointer offset in stack */ ++ long s; /* stack pointer offset from previous frame */ ++ unsigned long a; /* flags */ ++ } ++ data; ++} ++unwindnode; ++ ++/* An unwindhead holds the table of address node slots as well as the ++ * internal list of memory blocks allocated for address node slots. ++ */ ++typedef struct unwindhead ++{ ++ heaphead heap; /* pointer to heap */ ++ slottable table; /* table of address nodes */ ++ treeroot itree; /* internal list of memory blocks */ ++ treeroot dtree; /* tree for sorting */ ++ size_t size; /* memory used by internal blocks */ ++ char init; /* initialization flag */ ++} ++unwindhead; ++ ++static unwindhead unwindcache; ++ ++/* Initialise the fields of an unwindhead so that there are no allocated, ++ * freed or free blocks. ++ */ ++ ++static ++void ++newunwindcache(void) ++{ ++ struct { char x; unwindnode y; } z; ++ long n; ++ ++ __mp_newheap(&unwindcache.heap); ++ /* Determine the minimum alignment for an unwind node on this ++ * system and force the alignment to be a power of two. This ++ * information is used when initialising the slot table. ++ */ ++ n = (char *) &z.y - &z.x; ++ __mp_newslots(&unwindcache.table, sizeof(unwindnode), __mp_poweroftwo(n)); ++ __mp_newtree(&unwindcache.itree); ++ __mp_newtree(&unwindcache.dtree); ++ unwindcache.size = 0; ++ unwindcache.init = 1; ++} ++ ++ ++/* Forget all unwind information. ++ */ ++ ++static ++void ++deleteunwindcache(void) ++{ ++ /* We don't need to explicitly free any memory as this is dealt with ++ * at a lower level by the heap manager. ++ */ ++ __mp_deleteheap(&unwindcache.heap); ++ unwindcache.table.free = NULL; ++ unwindcache.table.size = 0; ++ __mp_newtree(&unwindcache.itree); ++ __mp_newtree(&unwindcache.dtree); ++ unwindcache.size = 0; ++ unwindcache.init = 0; ++} ++ ++ ++/* Allocate a new unwind node. ++ */ ++ ++static ++unwindnode * ++getunwindnode(void) ++{ ++ unwindnode *n; ++ heapnode *p; ++ ++ /* If we have no more allocation node slots left then we must allocate ++ * some more memory for them. An extra MP_ALLOCFACTOR pages of memory ++ * should suffice. ++ */ ++ if ((n = (unwindnode *) __mp_getslot(&unwindcache.table)) == NULL) ++ { ++ if ((p = __mp_heapalloc(&unwindcache.heap, unwindcache.heap.memory.page * MP_ALLOCFACTOR, ++ unwindcache.table.entalign, 1)) == NULL) ++ return NULL; ++ __mp_initslots(&unwindcache.table, p->block, p->size); ++ n = (unwindnode *) __mp_getslot(&unwindcache.table); ++ __mp_treeinsert(&unwindcache.itree, &n->index.node, (unsigned long) p->block); ++ n->index.block = p->block; ++ n->index.size = p->size; ++ unwindcache.size += p->size; ++ n = (unwindnode *) __mp_getslot(&unwindcache.table); ++ } ++ return n; ++} ++ ++/* Search for the unwind node associated with a given address. ++ */ ++static ++unwindnode * ++findunwindnode(unsigned long p) ++{ ++ return (unwindnode *) __mp_search(unwindcache.dtree.root, p); ++} ++ ++ + /* Determine the stack pointer and return address of the previous stack frame + * by performing code reading. + */ +@@ -289,8 +420,9 @@ + unwind(frameinfo *f) + { + long p, m, s; +- unsigned long a, i, q, t, b, r; ++ unsigned long a, i, q, t, b, r, k; + unsigned short l, u; ++ unwindnode *n = NULL; + + s = -1; + p = m = 0; +@@ -322,7 +454,23 @@ + #endif + /* Save initial code-reading starting point. + */ +- r = f->ra; ++ r = k = f->ra; ++ /* Create the cache if not yet created. ++ */ ++ if (!unwindcache.init) ++ { ++ newunwindcache(); ++ __mp_atexit(deleteunwindcache); ++ } ++ if ((n = findunwindnode(f->ra)) != NULL) ++ { ++ /* We've been here before, so get the cached information. ++ */ ++ p = n->data.p; ++ m = n->data.m; ++ s = n->data.s; ++ a = n->data.a; ++ } + /* Search for the return address offset in the stack frame. + */ + while (!((a & RA_OFFSET) && (a & SP_OFFSET)) && (f->ra < q)) +@@ -478,6 +626,19 @@ + return 1; + } + #endif ++ if (n == NULL) ++ { ++ if ((n = getunwindnode()) != NULL) ++ { ++ /* Cache the information we just got in the tree. ++ */ ++ n->data.p = p; ++ n->data.m = m; ++ n->data.s = s; ++ n->data.a = a; ++ __mp_treeinsert(&unwindcache.dtree, &n->data.node, k); ++ } ++ } + if (a & SP_IN_FP) + f->sp = f->fp; + if (m > 0) |