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author | Patrick Williams <iawillia@us.ibm.com> | 2010-05-21 07:37:12 -0500 |
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committer | Patrick Williams <iawillia@us.ibm.com> | 2010-05-21 07:37:12 -0500 |
commit | b9652b36ff9bfa429ff3e9756e7e43f0da4ea1a7 (patch) | |
tree | 6e4ad709b3c9ad1cf45905d1c420751429284634 | |
parent | d9d7e6c7247aaf5d2721d08a365e9c51ec18c870 (diff) | |
download | talos-hostboot-b9652b36ff9bfa429ff3e9756e7e43f0da4ea1a7.tar.gz talos-hostboot-b9652b36ff9bfa429ff3e9756e7e43f0da4ea1a7.zip |
Move pagemgr to generic lock free structure.
-rw-r--r-- | src/include/kernel/pagemgr.H | 5 | ||||
-rw-r--r-- | src/include/util/lockfree/stack.H | 47 | ||||
-rw-r--r-- | src/kernel/pagemgr.C | 24 |
3 files changed, 53 insertions, 23 deletions
diff --git a/src/include/kernel/pagemgr.H b/src/include/kernel/pagemgr.H index 1d7193b22..b99cedff2 100644 --- a/src/include/kernel/pagemgr.H +++ b/src/include/kernel/pagemgr.H @@ -2,6 +2,7 @@ #define __KERNEL_PAGEMGR_H #include <stdint.h> +#include <util/lockfree/stack.H> /** @class PageManager * @brief Manages the allocation of memory pages. @@ -31,9 +32,9 @@ class PageManager struct page_t { - page_t* next_page; + page_t* next; }; - page_t* first_page[BUCKETS]; + Util::Lockfree::Stack<page_t> first_page[BUCKETS]; page_t* pop_bucket(size_t); void push_bucket(page_t*, size_t); diff --git a/src/include/util/lockfree/stack.H b/src/include/util/lockfree/stack.H new file mode 100644 index 000000000..8f884e072 --- /dev/null +++ b/src/include/util/lockfree/stack.H @@ -0,0 +1,47 @@ +#ifndef __UTIL_LOCKFREE_STACK_H +#define __UTIL_LOCKFREE_STACK_H + +#include <stddef.h> + +namespace Util +{ + namespace Lockfree + { + template <typename _T> + class Stack + { + public: + Stack() : head(NULL) {}; + + _T* pop(); + void push(_T*); + + private: + _T* head; + }; + + template <typename _T> + _T* Stack<_T>::pop() + { + _T * h = head; + if (NULL == h) return h; + if (!__sync_bool_compare_and_swap(&head, + h, + h->next)) + return pop(); + return h; + } + + template <typename _T> + void Stack<_T>::push(_T* p) + { + p->next = head; + if (!__sync_bool_compare_and_swap(&head, + p->next, + p)) + push(p); + } + } +} + +#endif diff --git a/src/kernel/pagemgr.C b/src/kernel/pagemgr.C index e5d9ec321..728222a05 100644 --- a/src/kernel/pagemgr.C +++ b/src/kernel/pagemgr.C @@ -33,10 +33,6 @@ PageManager::PageManager() length, (uint64_t)page); - // Clear page buckets. - for(int i = 0; i < BUCKETS; i++) - first_page[i] = NULL; - // Allocate pages to buckets. size_t page_length = BUCKETS-1; while(length > 0) @@ -44,8 +40,7 @@ PageManager::PageManager() while (length < (1 << page_length)) page_length--; - page->next_page = first_page[page_length]; - first_page[page_length] = page; + first_page[page_length].push(page); page = (page_t*)((uint64_t)page + (1 << page_length)*PAGESIZE); length -= (1 << page_length); } @@ -91,7 +86,7 @@ PageManager::page_t* PageManager::pop_bucket(size_t n) { if (n >= BUCKETS) return NULL; - page_t* p = first_page[n]; + page_t* p = first_page[n].pop(); if (NULL == p) { @@ -101,24 +96,11 @@ PageManager::page_t* PageManager::pop_bucket(size_t n) push_bucket((page_t*) (((uint64_t)p) + (PAGESIZE * (1 << n))), n); } - else - { - // This bucket appears to have items in it, allocate one. - if (!__sync_bool_compare_and_swap(&first_page[n], - p, - p->next_page)) - return pop_bucket(n); - } return p; } void PageManager::push_bucket(page_t* p, size_t n) { if (n >= BUCKETS) return; - - p->next_page = first_page[n]; - if (!__sync_bool_compare_and_swap(&first_page[n], - p->next_page, - p)) - push_bucket(p, n); + first_page[n].push(p); } |