Namespace kernel version macros

[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 3efa1d12ecb6bc6cffc12ffadd321934a55d95de..a49bb79bc7885d7a4440760df2323d7f7e531030 100644 (file)
--- a/lib/ringbuffer/ring_buffer_backend.c
+++ b/lib/ringbuffer/ring_buffer_backend.c
@@ -1,21 +1,8 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 OR LGPL-2.1)
+ *
  * ring_buffer_backend.c
  *
  * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <linux/stddef.h>
@@ -29,7 +16,8 @@
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 
-#include <wrapper/vmalloc.h>   /* for wrapper_vmalloc_sync_all() */
+#include <wrapper/mm.h>
+#include <wrapper/vmalloc.h>   /* for wrapper_vmalloc_sync_mappings() */
 #include <wrapper/ringbuffer/config.h>
 #include <wrapper/ringbuffer/backend.h>
 #include <wrapper/ringbuffer/frontend.h>
@@ -56,6 +44,25 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
        unsigned long i;
 
        num_pages = size >> PAGE_SHIFT;
+
+       /*
+        * Verify that there is enough free pages available on the system for
+        * the current allocation request.
+        * wrapper_check_enough_free_pages uses si_mem_available() if available
+        * and returns if there should be enough free pages based on the
+        * current estimate.
+        */
+       if (!wrapper_check_enough_free_pages(num_pages))
+               goto not_enough_pages;
+
+       /*
+        * Set the current user thread as the first target of the OOM killer.
+        * If the estimate received by si_mem_available() was off, and we do
+        * end up running out of memory because of this buffer allocation, we
+        * want to kill the offending app first.
+        */
+       wrapper_set_current_oom_origin();
+
        num_pages_per_subbuf = num_pages >> get_count_order(num_subbuf);
        subbuf_size = chanb->subbuf_size;
        num_subbuf_alloc = num_subbuf;
@@ -149,7 +156,8 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
         * If kmalloc ever uses vmalloc underneath, make sure the buffer pages
         * will not fault.
         */
-       wrapper_vmalloc_sync_all();
+       wrapper_vmalloc_sync_mappings();
+       wrapper_clear_current_oom_origin();
        vfree(pages);
        return 0;
 
@@ -166,6 +174,8 @@ depopulate:
 array_error:
        vfree(pages);
 pages_error:
+       wrapper_clear_current_oom_origin();
+not_enough_pages:
        return -ENOMEM;
 }
 
@@ -249,7 +259,7 @@ void channel_backend_reset(struct channel_backend *chanb)
        chanb->start_tsc = config->cb.ring_buffer_clock_read(chan);
 }
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
 
 /*
  * No need to implement a "dead" callback to do a buffer switch here,
@@ -281,7 +291,7 @@ int lttng_cpuhp_rb_backend_prepare(unsigned int cpu,
 }
 EXPORT_SYMBOL_GPL(lttng_cpuhp_rb_backend_prepare);
 
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 
 #ifdef CONFIG_HOTPLUG_CPU
 
@@ -331,7 +341,7 @@ int lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
 
 #endif
 
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 
 /**
  * channel_backend_init - initialize a channel backend
@@ -409,13 +419,13 @@ int channel_backend_init(struct channel_backend *chanb,
                if (!chanb->buf)
                        goto free_cpumask;
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
                chanb->cpuhp_prepare.component = LTTNG_RING_BUFFER_BACKEND;
                ret = cpuhp_state_add_instance(lttng_rb_hp_prepare,
                        &chanb->cpuhp_prepare.node);
                if (ret)
                        goto free_bufs;
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 
                {
                        /*
@@ -452,7 +462,7 @@ int channel_backend_init(struct channel_backend *chanb,
                        }
 #endif
                }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
        } else {
                chanb->buf = kzalloc(sizeof(struct lib_ring_buffer), GFP_KERNEL);
                if (!chanb->buf)
@@ -467,16 +477,18 @@ int channel_backend_init(struct channel_backend *chanb,
 
 free_bufs:
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-               ret = cpuhp_state_remove_instance(lttng_rb_hp_prepare,
-                               &chanb->cpuhp_prepare.node);
-               WARN_ON(ret);
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
+               /*
+                * Teardown of lttng_rb_hp_prepare instance
+                * on "add" error is handled within cpu hotplug,
+                * no teardown to do from the caller.
+                */
+#else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 #ifdef CONFIG_HOTPLUG_CPU
                put_online_cpus();
                unregister_hotcpu_notifier(&chanb->cpu_hp_notifier);
 #endif
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
                for_each_possible_cpu(i) {
                        struct lib_ring_buffer *buf =
                                per_cpu_ptr(chanb->buf, i);
@@ -505,15 +517,15 @@ void channel_backend_unregister_notifiers(struct channel_backend *chanb)
        const struct lib_ring_buffer_config *config = &chanb->config;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0))
                int ret;
 
                ret = cpuhp_state_remove_instance(lttng_rb_hp_prepare,
                                &chanb->cpuhp_prepare.node);
                WARN_ON(ret);
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
                unregister_hotcpu_notifier(&chanb->cpu_hp_notifier);
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
        }
 }