[IA64] make uncached allocator more node aware

The uncached allocator has a function, uncached_get_new_chunk(), that needs
to be serialized on a per node basis. It also has a global variable,
allocated_granules, which should be defined on a per node basis and protected
by that serialization. Additionally, all error returns from functions called
(like ia64_pal_mc_drain()) should be handled appropriately.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Acked-by: Jes Sorenson <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/uncached.c b/arch/ia64/kernel/uncached.c
index 5f03b9e..4c73a67 100644 (file)
--- a/arch/ia64/kernel/uncached.c
+++ b/arch/ia64/kernel/uncached.c
@@ -32,32 +32,38 @@
 
 extern void __init efi_memmap_walk_uc(efi_freemem_callback_t, void *);
 
-#define MAX_UNCACHED_GRANULES  5
-static int allocated_granules;
+struct uncached_pool {
+       struct gen_pool *pool;
+       struct mutex add_chunk_mutex;   /* serialize adding a converted chunk */
+       int nchunks_added;              /* #of converted chunks added to pool */
+       atomic_t status;                /* smp called function's return status*/
+};
+
+#define MAX_CONVERTED_CHUNKS_PER_NODE  2
 
-struct gen_pool *uncached_pool[MAX_NUMNODES];
+struct uncached_pool uncached_pools[MAX_NUMNODES];
 
 
 static void uncached_ipi_visibility(void *data)
 {
        int status;
+       struct uncached_pool *uc_pool = (struct uncached_pool *)data;
 
        status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
        if ((status != PAL_VISIBILITY_OK) &&
            (status != PAL_VISIBILITY_OK_REMOTE_NEEDED))
-               printk(KERN_DEBUG "pal_prefetch_visibility() returns %i on "
-                      "CPU %i\n", status, raw_smp_processor_id());
+               atomic_inc(&uc_pool->status);
 }
 
 
 static void uncached_ipi_mc_drain(void *data)
 {
        int status;
+       struct uncached_pool *uc_pool = (struct uncached_pool *)data;
 
        status = ia64_pal_mc_drain();
-       if (status)
-               printk(KERN_WARNING "ia64_pal_mc_drain() failed with %i on "
-                      "CPU %i\n", status, raw_smp_processor_id());
+       if (status != PAL_STATUS_SUCCESS)
+               atomic_inc(&uc_pool->status);
 }
 
 
@@ -70,21 +76,34 @@ static void uncached_ipi_mc_drain(void *data)
  * This is accomplished by first allocating a granule of cached memory pages
  * and then converting them to uncached memory pages.
  */
-static int uncached_add_chunk(struct gen_pool *pool, int nid)
+static int uncached_add_chunk(struct uncached_pool *uc_pool, int nid)
 {
        struct page *page;
-       int status, i;
+       int status, i, nchunks_added = uc_pool->nchunks_added;
        unsigned long c_addr, uc_addr;
 
-       if (allocated_granules >= MAX_UNCACHED_GRANULES)
+       if (mutex_lock_interruptible(&uc_pool->add_chunk_mutex) != 0)
+               return -1;      /* interrupted by a signal */
+
+       if (uc_pool->nchunks_added > nchunks_added) {
+               /* someone added a new chunk while we were waiting */
+               mutex_unlock(&uc_pool->add_chunk_mutex);
+               return 0;
+       }
+
+       if (uc_pool->nchunks_added >= MAX_CONVERTED_CHUNKS_PER_NODE) {
+               mutex_unlock(&uc_pool->add_chunk_mutex);
                return -1;
+       }
 
        /* attempt to allocate a granule's worth of cached memory pages */
 
        page = alloc_pages_node(nid, GFP_KERNEL | __GFP_ZERO,
                                IA64_GRANULE_SHIFT-PAGE_SHIFT);
-       if (!page)
+       if (!page) {
+               mutex_unlock(&uc_pool->add_chunk_mutex);
                return -1;
+       }
 
        /* convert the memory pages from cached to uncached */
 
@@ -102,11 +121,14 @@ static int uncached_add_chunk(struct gen_pool *pool, int nid)
        flush_tlb_kernel_range(uc_addr, uc_adddr + IA64_GRANULE_SIZE);
 
        status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
-       if (!status) {
-               status = smp_call_function(uncached_ipi_visibility, NULL, 0, 1);
-               if (status)
+       if (status == PAL_VISIBILITY_OK_REMOTE_NEEDED) {
+               atomic_set(&uc_pool->status, 0);
+               status = smp_call_function(uncached_ipi_visibility, uc_pool,
+                                          0, 1);
+               if (status || atomic_read(&uc_pool->status))
                        goto failed;
-       }
+       } else if (status != PAL_VISIBILITY_OK)
+               goto failed;
 
        preempt_disable();
 
@@ -120,20 +142,24 @@ static int uncached_add_chunk(struct gen_pool *pool, int nid)
 
        preempt_enable();
 
-       ia64_pal_mc_drain();
-       status = smp_call_function(uncached_ipi_mc_drain, NULL, 0, 1);
-       if (status)
+       status = ia64_pal_mc_drain();
+       if (status != PAL_STATUS_SUCCESS)
+               goto failed;
+       atomic_set(&uc_pool->status, 0);
+       status = smp_call_function(uncached_ipi_mc_drain, uc_pool, 0, 1);
+       if (status || atomic_read(&uc_pool->status))
                goto failed;
 
        /*
         * The chunk of memory pages has been converted to uncached so now we
         * can add it to the pool.
         */
-       status = gen_pool_add(pool, uc_addr, IA64_GRANULE_SIZE, nid);
+       status = gen_pool_add(uc_pool->pool, uc_addr, IA64_GRANULE_SIZE, nid);
        if (status)
                goto failed;
 
-       allocated_granules++;
+       uc_pool->nchunks_added++;
+       mutex_unlock(&uc_pool->add_chunk_mutex);
        return 0;
 
        /* failed to convert or add the chunk so give it back to the kernel */
@@ -142,6 +168,7 @@ failed:
                ClearPageUncached(&page[i]);
 
        free_pages(c_addr, IA64_GRANULE_SHIFT-PAGE_SHIFT);
+       mutex_unlock(&uc_pool->add_chunk_mutex);
        return -1;
 }
 
@@ -158,7 +185,7 @@ failed:
 unsigned long uncached_alloc_page(int starting_nid)
 {
        unsigned long uc_addr;
-       struct gen_pool *pool;
+       struct uncached_pool *uc_pool;
        int nid;
 
        if (unlikely(starting_nid >= MAX_NUMNODES))
@@ -171,14 +198,14 @@ unsigned long uncached_alloc_page(int starting_nid)
        do {
                if (!node_online(nid))
                        continue;
-               pool = uncached_pool[nid];
-               if (pool == NULL)
+               uc_pool = &uncached_pools[nid];
+               if (uc_pool->pool == NULL)
                        continue;
                do {
-                       uc_addr = gen_pool_alloc(pool, PAGE_SIZE);
+                       uc_addr = gen_pool_alloc(uc_pool->pool, PAGE_SIZE);
                        if (uc_addr != 0)
                                return uc_addr;
-               } while (uncached_add_chunk(pool, nid) == 0);
+               } while (uncached_add_chunk(uc_pool, nid) == 0);
 
        } while ((nid = (nid + 1) % MAX_NUMNODES) != starting_nid);
 
@@ -197,7 +224,7 @@ EXPORT_SYMBOL(uncached_alloc_page);
 void uncached_free_page(unsigned long uc_addr)
 {
        int nid = paddr_to_nid(uc_addr - __IA64_UNCACHED_OFFSET);
-       struct gen_pool *pool = uncached_pool[nid];
+       struct gen_pool *pool = uncached_pools[nid].pool;
 
        if (unlikely(pool == NULL))
                return;
@@ -224,7 +251,7 @@ static int __init uncached_build_memmap(unsigned long uc_start,
                                        unsigned long uc_end, void *arg)
 {
        int nid = paddr_to_nid(uc_start - __IA64_UNCACHED_OFFSET);
-       struct gen_pool *pool = uncached_pool[nid];
+       struct gen_pool *pool = uncached_pools[nid].pool;
        size_t size = uc_end - uc_start;
 
        touch_softlockup_watchdog();
@@ -242,7 +269,8 @@ static int __init uncached_init(void)
        int nid;
 
        for_each_online_node(nid) {
-               uncached_pool[nid] = gen_pool_create(PAGE_SHIFT, nid);
+               uncached_pools[nid].pool = gen_pool_create(PAGE_SHIFT, nid);
+               mutex_init(&uncached_pools[nid].add_chunk_mutex);
        }
 
        efi_memmap_walk_uc(uncached_build_memmap, NULL);