Merge r7346 from trunk

git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/3.3.x@7607 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scst/README

@@ -363,6 +363,10 @@ in/out in Makefile and scst.h:
    target attribute on the remote node. See below for more details.
    Disabled by default for safety.
 
+ - CONFIG_SCST_NO_TOTAL_MEM_CHECKS - disables checks of allocated
+   memory, see scst_max_cmd_mem below. Allows to avoid 2 global
+   variables on the fast path, hence get better multi-queue performance.
+
 HIGHMEM kernel configurations are fully supported, but not recommended
 for performance reasons, except for scst_user, where they are not
 supported, because this module deals with user supplied memory on a

scst/README_in-tree

@@ -253,6 +253,10 @@ your favorite kernel configuration Makefile target, e.g. "make xconfig":
    target attribute on the remote node. See below for more details.
    Disabled by default for safety.
 
+ - CONFIG_SCST_NO_TOTAL_MEM_CHECKS - disables checks of allocated
+   memory, see scst_max_cmd_mem below. Allows to avoid 2 global
+   variables on the fast path, hence get better multi-queue performance.
+
 HIGHMEM kernel configurations are fully supported, but not recommended
 for performance reasons.
 

scst/include/scst.h

@@ -30,6 +30,7 @@
 /** See README for description of those conditional defines **/
 #define CONFIG_SCST_DIF_INJECT_CORRUPTED_TAGS
 /* #define CONFIG_SCST_FORWARD_MODE_PASS_THROUGH */
+#define CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 
 #include <linux/types.h>
 #ifndef INSIDE_KERNEL_TREE

scst/src/scst_main.c

@@ -2746,9 +2746,14 @@ static int __init init_scst(void)
 		goto out_thread_free;
 #endif
 
+#ifdef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
+	PRINT_INFO("SCST version %s loaded successfully (global max mem for commands "
+		"ignored, per device %dMB)", SCST_VERSION_STRING, scst_max_dev_cmd_mem);
+#else
 	PRINT_INFO("SCST version %s loaded successfully (max mem for "
 		"commands %dMB, per device %dMB)", SCST_VERSION_STRING,
 		scst_max_cmd_mem, scst_max_dev_cmd_mem);
+#endif
 
 	scst_print_config();
 

scst/src/scst_mem.c

@@ -56,7 +56,9 @@ static struct lockdep_map scst_pool_dep_map =
 
 static struct sgv_pool *sgv_norm_clust_pool, *sgv_norm_pool, *sgv_dma_pool;
 
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 static atomic_t sgv_pages_total = ATOMIC_INIT(0);
+#endif
 
 /* Both read-only */
 static int sgv_hi_wmk;
@@ -70,7 +72,9 @@ static DEFINE_MUTEX(sgv_pools_mutex);
 static atomic_t sgv_releases_on_hiwmk = ATOMIC_INIT(0);
 static atomic_t sgv_releases_on_hiwmk_failed = ATOMIC_INIT(0);
 
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 static atomic_t sgv_other_total_alloc = ATOMIC_INIT(0);
+#endif
 
 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 23))
 static struct shrinker *sgv_shrinker;
@@ -182,7 +186,9 @@ static void __sgv_purge_from_cache(struct sgv_pool_obj *obj)
 	pool->inactive_cached_pages -= pages;
 	sgv_dec_cached_entries(pool, pages);
 
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	atomic_sub(pages, &sgv_pages_total);
+#endif
 
 	return;
 }
@@ -223,7 +229,11 @@ static int sgv_shrink_pool(struct sgv_pool *pool, int nr, int min_interval,
 	spin_lock_bh(&pool->sgv_pool_lock);
 
 	while (!list_empty(&pool->sorted_recycling_list) &&
+#ifdef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
+			true) {
+#else
 			(atomic_read(&sgv_pages_total) > sgv_lo_wmk)) {
+#endif
 		struct sgv_pool_obj *obj = list_first_entry(
 			&pool->sorted_recycling_list,
 			struct sgv_pool_obj, sorted_recycling_list_entry);
@@ -305,7 +315,9 @@ static unsigned long __sgv_can_be_shrunk(void)
 	spin_unlock_bh(&sgv_pools_lock);
 
 	res = max(0, inactive_pages - sgv_lo_wmk);
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	TRACE_MEM("Can free %ld (total %d)", res, atomic_read(&sgv_pages_total));
+#endif
 
 	TRACE_EXIT_RES(res);
 	return res;
@@ -790,6 +802,7 @@ static void sgv_put_obj(struct sgv_pool_obj *obj)
 static int sgv_hiwmk_check(int pages_to_alloc)
 {
 	int res = 0;
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	int pages = pages_to_alloc;
 
 	pages += atomic_read(&sgv_pages_total);
@@ -820,16 +833,18 @@ static int sgv_hiwmk_check(int pages_to_alloc)
 out_unlock:
 	TRACE_MEM("pages_to_alloc %d, new total %d", pages_to_alloc,
 		atomic_read(&sgv_pages_total));
-
+#endif
 	return res;
 }
 
 /* No locks */
 static void sgv_hiwmk_uncheck(int pages)
 {
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	atomic_sub(pages, &sgv_pages_total);
 	TRACE_MEM("pages %d, new total %d", pages,
 		atomic_read(&sgv_pages_total));
+#endif
 	return;
 }
 
@@ -1246,7 +1261,9 @@ struct scatterlist *scst_alloc_sg(int size, gfp_t gfp_mask, int *count)
 
 	TRACE_ENTRY();
 
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	atomic_inc(&sgv_other_total_alloc);
+#endif
 
 	if (unlikely(sgv_hiwmk_check(pages) != 0)) {
 		if (!no_fail) {
@@ -1945,6 +1962,7 @@ int sgv_procinfo_show(struct seq_file *seq, void *v)
 	}
 	spin_unlock_bh(&sgv_pools_lock);
 
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	seq_printf(seq, "%-42s %d/%d\n%-42s %d/%d\n%-42s %d/%d\n\n",
 		"Inactive/active pages", inactive_pages,
 		atomic_read(&sgv_pages_total) - inactive_pages,
@@ -1952,6 +1970,7 @@ int sgv_procinfo_show(struct seq_file *seq, void *v)
 		"Hi watermark releases/failures",
 		atomic_read(&sgv_releases_on_hiwmk),
 		atomic_read(&sgv_releases_on_hiwmk_failed));
+#endif
 
 	seq_printf(seq, "%-30s %-11s %-11s %-11s %-11s", "Name", "Hit", "Total",
 		"% merged", "Cached (P/I/O)");
@@ -1962,8 +1981,10 @@ int sgv_procinfo_show(struct seq_file *seq, void *v)
 	}
 	mutex_unlock(&sgv_pools_mutex);
 
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	seq_printf(seq, "\n%-42s %-11d\n", "other",
 		atomic_read(&sgv_other_total_alloc));
+#endif
 
 	TRACE_EXIT();
 	return 0;
@@ -2070,6 +2091,9 @@ static ssize_t sgv_sysfs_global_stat_show(struct kobject *kobj,
 	}
 	spin_unlock_bh(&sgv_pools_lock);
 
+#ifdef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
+	res = sprintf(buf, "%-42s %d\n", "Inactive pages", inactive_pages);
+#else
 	res = sprintf(buf, "%-42s %d/%d\n%-42s %d/%d\n%-42s %d/%d\n"
 		"%-42s %-11d\n",
 		"Inactive/active pages", inactive_pages,
@@ -2079,6 +2103,7 @@ static ssize_t sgv_sysfs_global_stat_show(struct kobject *kobj,
 		atomic_read(&sgv_releases_on_hiwmk),
 		atomic_read(&sgv_releases_on_hiwmk_failed),
 		"Other allocs", atomic_read(&sgv_other_total_alloc));
+#endif
 
 	TRACE_EXIT();
 	return res;
@@ -2091,7 +2116,9 @@ static ssize_t sgv_sysfs_global_stat_reset(struct kobject *kobj,
 
 	atomic_set(&sgv_releases_on_hiwmk, 0);
 	atomic_set(&sgv_releases_on_hiwmk_failed, 0);
+#ifndef CONFIG_SCST_NO_TOTAL_MEM_CHECKS
 	atomic_set(&sgv_other_total_alloc, 0);
+#endif
 
 	PRINT_INFO("%s", "Global SGV pool statistics reset");