fix: cpu/hotplug: Remove deprecated CPU-hotplug functions. (v5.15)

[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 9d199e516aacbaf009538faf394671113e18bf70..94bdc10780ef850844a8d4dff4b7c141bf901da1 100644 (file)
--- a/lib/ringbuffer/ring_buffer_backend.c
+++ b/lib/ringbuffer/ring_buffer_backend.c
@@ -12,11 +12,12 @@
 #include <linux/delay.h>
 #include <linux/errno.h>
 #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/cpu.h>
+#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>
@@ -43,6 +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;
@@ -136,7 +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;
 
@@ -153,6 +174,8 @@ depopulate:
 array_error:
        vfree(pages);
 pages_error:
+       wrapper_clear_current_oom_origin();
+not_enough_pages:
        return -ENOMEM;
 }
 
@@ -236,7 +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,
@@ -268,7 +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
 
@@ -318,7 +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
@@ -396,13 +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)) */
 
                {
                        /*
@@ -422,14 +445,14 @@ int channel_backend_init(struct channel_backend *chanb,
                        chanb->cpu_hp_notifier.priority = 5;
                        register_hotcpu_notifier(&chanb->cpu_hp_notifier);
 
-                       get_online_cpus();
+                       lttng_cpus_read_lock();
                        for_each_online_cpu(i) {
                                ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
                                                         chanb, i);
                                if (ret)
                                        goto free_bufs; /* cpu hotplug locked */
                        }
-                       put_online_cpus();
+                       lttng_cpus_read_unlock();
 #else
                        for_each_possible_cpu(i) {
                                ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
@@ -439,7 +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)
@@ -454,18 +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))
+#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 (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
+#else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,10,0)) */
 #ifdef CONFIG_HOTPLUG_CPU
-               put_online_cpus();
+               lttng_cpus_read_unlock();
                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);
@@ -494,15 +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)) */
        }
 }