-/*
+/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
+ *
* 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>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/oom.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 <ringbuffer/config.h>
+#include <ringbuffer/backend.h>
+#include <ringbuffer/frontend.h>
/**
* lib_ring_buffer_backend_allocate - allocate a channel buffer
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 (num_pages >= si_mem_available())
+ 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.
+ */
+ 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;
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)));
+ bufb->array = kvmalloc_node(ALIGN(sizeof(*bufb->array)
+ * num_subbuf_alloc,
+ 1 << INTERNODE_CACHE_SHIFT),
+ 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;
}
/* Allocate backend pages array elements */
for (i = 0; i < num_subbuf_alloc; i++) {
bufb->array[i] =
- kzalloc_node(ALIGN(
+ kvzalloc_node(ALIGN(
sizeof(struct lib_ring_buffer_backend_pages) +
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;
}
/* Allocate write-side subbuffer table */
- bufb->buf_wsb = kzalloc_node(ALIGN(
+ bufb->buf_wsb = kvzalloc_node(ALIGN(
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;
bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
/* Allocate subbuffer packet counter table */
- bufb->buf_cnt = kzalloc_node(ALIGN(
+ bufb->buf_cnt = kvzalloc_node(ALIGN(
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;
}
}
- /*
- * If kmalloc ever uses vmalloc underneath, make sure the buffer pages
- * will not fault.
- */
- wrapper_vmalloc_sync_all();
- kfree(pages);
+ clear_current_oom_origin();
+ vfree(pages);
return 0;
free_wsb:
- kfree(bufb->buf_wsb);
+ kvfree(bufb->buf_wsb);
free_array:
for (i = 0; (i < num_subbuf_alloc && bufb->array[i]); i++)
- kfree(bufb->array[i]);
+ kvfree(bufb->array[i]);
depopulate:
/* Free all allocated pages */
for (i = 0; (i < num_pages && pages[i]); i++)
__free_page(pages[i]);
- kfree(bufb->array);
+ kvfree(bufb->array);
array_error:
- kfree(pages);
+ vfree(pages);
pages_error:
+ clear_current_oom_origin();
+not_enough_pages:
return -ENOMEM;
}
if (chanb->extra_reader_sb)
num_subbuf_alloc++;
- kfree(bufb->buf_wsb);
- kfree(bufb->buf_cnt);
+ kvfree(bufb->buf_wsb);
+ kvfree(bufb->buf_cnt);
for (i = 0; i < num_subbuf_alloc; i++) {
for (j = 0; j < bufb->num_pages_per_subbuf; j++)
__free_page(pfn_to_page(bufb->array[i]->p[j].pfn));
- kfree(bufb->array[i]);
+ kvfree(bufb->array[i]);
}
- kfree(bufb->array);
+ kvfree(bufb->array);
bufb->allocated = 0;
}
chanb->start_tsc = config->cb.ring_buffer_clock_read(chan);
}
-#ifdef CONFIG_HOTPLUG_CPU
-/**
- * lib_ring_buffer_cpu_hp_callback - CPU hotplug callback
- * @nb: notifier block
- * @action: hotplug action to take
- * @hcpu: CPU number
- *
- * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
+/*
+ * No need to implement a "dead" callback to do a buffer switch here,
+ * because it will happen when tracing is stopped, or will be done by
+ * switch timer CPU DEAD callback.
+ * We don't free buffers when CPU go away, because it would make trace
+ * data vanish, which is unwanted.
*/
-static
-int lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
+int lttng_cpuhp_rb_backend_prepare(unsigned int cpu,
+ struct lttng_cpuhp_node *node)
{
- unsigned int cpu = (unsigned long)hcpu;
- struct channel_backend *chanb = container_of(nb, struct channel_backend,
- cpu_hp_notifier);
+ struct channel_backend *chanb = container_of(node,
+ struct channel_backend, cpuhp_prepare);
const struct lib_ring_buffer_config *config = &chanb->config;
struct lib_ring_buffer *buf;
int ret;
CHAN_WARN_ON(chanb, config->alloc == RING_BUFFER_ALLOC_GLOBAL);
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- buf = per_cpu_ptr(chanb->buf, cpu);
- ret = lib_ring_buffer_create(buf, chanb, cpu);
- if (ret) {
- printk(KERN_ERR
- "ring_buffer_cpu_hp_callback: cpu %d "
- "buffer creation failed\n", cpu);
- return NOTIFY_BAD;
- }
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- /* No need to do a buffer switch here, because it will happen
- * when tracing is stopped, or will be done by switch timer CPU
- * DEAD callback. */
- break;
+ buf = per_cpu_ptr(chanb->buf, cpu);
+ ret = lib_ring_buffer_create(buf, chanb, cpu);
+ if (ret) {
+ printk(KERN_ERR
+ "ring_buffer_cpu_hp_callback: cpu %d "
+ "buffer creation failed\n", cpu);
+ return ret;
}
- return NOTIFY_OK;
+ return 0;
}
-#endif
+EXPORT_SYMBOL_GPL(lttng_cpuhp_rb_backend_prepare);
/**
* channel_backend_init - initialize a channel backend
if (!chanb->buf)
goto free_cpumask;
- /*
- * In case of non-hotplug cpu, if the ring-buffer is allocated
- * in early initcall, it will not be notified of secondary cpus.
- * In that off case, we need to allocate for all possible cpus.
- */
-#ifdef CONFIG_HOTPLUG_CPU
- /*
- * buf->backend.allocated test takes care of concurrent CPU
- * hotplug.
- * Priority higher than frontend, so we create the ring buffer
- * before we start the timer.
- */
- chanb->cpu_hp_notifier.notifier_call =
- lib_ring_buffer_cpu_hp_callback;
- chanb->cpu_hp_notifier.priority = 5;
- register_hotcpu_notifier(&chanb->cpu_hp_notifier);
-
- get_online_cpus();
- 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();
-#else
- for_each_possible_cpu(i) {
- ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
- chanb, i);
- if (ret)
- goto free_bufs; /* cpu hotplug locked */
- }
-#endif
+ 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 {
chanb->buf = kzalloc(sizeof(struct lib_ring_buffer), GFP_KERNEL);
if (!chanb->buf)
free_bufs:
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
+ /*
+ * Teardown of lttng_rb_hp_prepare instance
+ * on "add" error is handled within cpu hotplug,
+ * no teardown to do from the caller.
+ */
for_each_possible_cpu(i) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chanb->buf, i);
+ struct lib_ring_buffer *buf =
+ per_cpu_ptr(chanb->buf, i);
if (!buf->backend.allocated)
continue;
lib_ring_buffer_free(buf);
}
-#ifdef CONFIG_HOTPLUG_CPU
- put_online_cpus();
-#endif
free_percpu(chanb->buf);
} else
kfree(chanb->buf);
{
const struct lib_ring_buffer_config *config = &chanb->config;
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- unregister_hotcpu_notifier(&chanb->cpu_hp_notifier);
+ if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
+ int ret;
+
+ ret = cpuhp_state_remove_instance(lttng_rb_hp_prepare,
+ &chanb->cpuhp_prepare.node);
+ WARN_ON(ret);
+ }
}
/**
+ (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 */
}
projects / lttng-modules.git / blobdiff