Fix: handle large number of pages or subbuffers per buffer

[lttng-modules.git] / lib / ringbuffer / ring_buffer_backend.c

diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c
index 83a6e39b4b2df692c955c6930f04d432e4a2c88a..27554a1e46b447464b81f48c48d02eb87906a490 100644 (file)
--- a/lib/ringbuffer/ring_buffer_backend.c
+++ b/lib/ringbuffer/ring_buffer_backend.c
@@ -27,11 +27,12 @@
 #include <linux/slab.h>
 #include <linux/cpu.h>
 #include <linux/mm.h>
+#include <linux/vmalloc.h>
 
-#include "../../wrapper/vmalloc.h"     /* for wrapper_vmalloc_sync_all() */
-#include "../../wrapper/ringbuffer/config.h"
-#include "../../wrapper/ringbuffer/backend.h"
-#include "../../wrapper/ringbuffer/frontend.h"
+#include <wrapper/vmalloc.h>   /* for wrapper_vmalloc_sync_all() */
+#include <wrapper/ringbuffer/config.h>
+#include <wrapper/ringbuffer/backend.h>
+#include <wrapper/ringbuffer/frontend.h>
 
 /**
  * lib_ring_buffer_backend_allocate - allocate a channel buffer
@@ -64,22 +65,23 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
                num_subbuf_alloc++;
        }
 
-       pages = kmalloc_node(ALIGN(sizeof(*pages) * num_pages,
+       pages = vmalloc_node(ALIGN(sizeof(*pages) * num_pages,
                                   1 << INTERNODE_CACHE_SHIFT),
-                       GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
+                       cpu_to_node(max(bufb->cpu, 0)));
        if (unlikely(!pages))
                goto pages_error;
 
        bufb->array = kmalloc_node(ALIGN(sizeof(*bufb->array)
                                         * num_subbuf_alloc,
                                  1 << INTERNODE_CACHE_SHIFT),
-                       GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
+                       GFP_KERNEL | __GFP_NOWARN,
+                       cpu_to_node(max(bufb->cpu, 0)));
        if (unlikely(!bufb->array))
                goto array_error;
 
        for (i = 0; i < num_pages; i++) {
                pages[i] = alloc_pages_node(cpu_to_node(max(bufb->cpu, 0)),
-                                           GFP_KERNEL | __GFP_ZERO, 0);
+                               GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, 0);
                if (unlikely(!pages[i]))
                        goto depopulate;
        }
@@ -93,7 +95,8 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
                                sizeof(struct lib_ring_buffer_backend_page)
                                * num_pages_per_subbuf,
                                1 << INTERNODE_CACHE_SHIFT),
-                               GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
+                               GFP_KERNEL | __GFP_NOWARN,
+                               cpu_to_node(max(bufb->cpu, 0)));
                if (!bufb->array[i])
                        goto free_array;
        }
@@ -103,7 +106,8 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
                                sizeof(struct lib_ring_buffer_backend_subbuffer)
                                * num_subbuf,
                                1 << INTERNODE_CACHE_SHIFT),
-                               GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
+                               GFP_KERNEL | __GFP_NOWARN,
+                               cpu_to_node(max(bufb->cpu, 0)));
        if (unlikely(!bufb->buf_wsb))
                goto free_array;
 
@@ -122,7 +126,8 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
                                sizeof(struct lib_ring_buffer_backend_counts)
                                * num_subbuf,
                                1 << INTERNODE_CACHE_SHIFT),
-                       GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0)));
+                       GFP_KERNEL | __GFP_NOWARN,
+                       cpu_to_node(max(bufb->cpu, 0)));
        if (unlikely(!bufb->buf_cnt))
                goto free_wsb;
 
@@ -145,7 +150,7 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
         * will not fault.
         */
        wrapper_vmalloc_sync_all();
-       kfree(pages);
+       vfree(pages);
        return 0;
 
 free_wsb:
@@ -159,7 +164,7 @@ depopulate:
                __free_page(pages[i]);
        kfree(bufb->array);
 array_error:
-       kfree(pages);
+       vfree(pages);
 pages_error:
        return -ENOMEM;
 }
@@ -422,6 +427,7 @@ free_bufs:
                }
 #ifdef CONFIG_HOTPLUG_CPU
                put_online_cpus();
+               unregister_hotcpu_notifier(&chanb->cpu_hp_notifier);
 #endif
                free_percpu(chanb->buf);
        } else
@@ -693,8 +699,7 @@ void _lib_ring_buffer_copy_from_user_inatomic(struct lib_ring_buffer_backend *bu
                                                        + (offset & ~PAGE_MASK),
                                                        src, pagecpy) != 0;
                if (ret > 0) {
-                       offset += (pagecpy - ret);
-                       len -= (pagecpy - ret);
+                       /* Copy failed. */
                        _lib_ring_buffer_memset(bufb, offset, 0, len, 0);
                        break; /* stop copy */
                }