From 621876ff446885d32922f34681790581c994f9a5 Mon Sep 17 00:00:00 2001 From: Chen Guo Date: Mon, 6 Dec 2010 00:15:42 -0800 Subject: sort: use mutexes, not spinlocks (avoid busy loop on blocked output) Running a command like this on a multi-core system sort < big-file | less would peg all processors at near 100% utilization. * src/sort.c: (struct merge_node) Change member lock to mutex. All uses changed. * tests/Makefile.am (XFAIL_TESTS): Remove definition, now that this test passes once again. I.e., the sort-spinlock-abuse test no longer fails. * NEWS (Bug reports): Mention this. Reported by DJ Lucas in http://debbugs.gnu.org/7489. --- src/sort.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'src') diff --git a/src/sort.c b/src/sort.c index a4c2cbf90..9cfc8144f 100644 --- a/src/sort.c +++ b/src/sort.c @@ -241,7 +241,7 @@ struct merge_node struct merge_node *parent; /* Parent node. */ unsigned int level; /* Level in merge tree. */ bool queued; /* Node is already in heap. */ - pthread_spinlock_t lock; /* Lock for node operations. */ + pthread_mutex_t lock; /* Lock for node operations. */ }; /* Priority queue of merge nodes. */ @@ -3157,7 +3157,7 @@ compare_nodes (void const *a, void const *b) static inline void lock_node (struct merge_node *node) { - pthread_spin_lock (&node->lock); + pthread_mutex_lock (&node->lock); } /* Unlock a merge tree NODE. */ @@ -3165,7 +3165,7 @@ lock_node (struct merge_node *node) static inline void unlock_node (struct merge_node *node) { - pthread_spin_unlock (&node->lock); + pthread_mutex_unlock (&node->lock); } /* Destroy merge QUEUE. */ @@ -3479,7 +3479,7 @@ sortlines (struct line *restrict lines, struct line *restrict dest, node.parent = parent; node.level = parent->level + 1; node.queued = false; - pthread_spin_init (&node.lock, PTHREAD_PROCESS_PRIVATE); + pthread_mutex_init (&node.lock, NULL); /* Calculate thread arguments. */ unsigned long int lo_threads = nthreads / 2; @@ -3515,7 +3515,7 @@ sortlines (struct line *restrict lines, struct line *restrict dest, merge_loop (queue, total_lines, tfp, temp_output); } - pthread_spin_destroy (&node.lock); + pthread_mutex_destroy (&node.lock); } /* Scan through FILES[NTEMPS .. NFILES-1] looking for a file that is @@ -3799,12 +3799,12 @@ sort (char * const *files, size_t nfiles, char const *output_file, node.parent = NULL; node.level = MERGE_END; node.queued = false; - pthread_spin_init (&node.lock, PTHREAD_PROCESS_PRIVATE); + pthread_mutex_init (&node.lock, NULL); sortlines (line, line, nthreads, buf.nlines, &node, true, &queue, tfp, temp_output); queue_destroy (&queue); - pthread_spin_destroy (&node.lock); + pthread_mutex_destroy (&node.lock); } else write_unique (line - 1, tfp, temp_output); -- cgit v1.2.3-54-g00ecf