Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ring-buffer: Export buffer_data_page and macros
In preparation for allowing the writing of ring-buffer compliant pages
outside of ring_buffer.c, move buffer_data_page and timestamps encoding
macros into the publicly available ring_buffer_types.h.
Link: https://patch.msgid.link/20260309162516.2623589-13-vdonnefort@google.com
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
authored by
Vincent Donnefort
and committed by
Steven Rostedt (Google)
93ae1b76
5f3efd1d
+42
-35
+41
include/linux/ring_buffer_types.h
+41
include/linux/ring_buffer_types.h
···
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_RING_BUFFER_TYPES_H
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#define _LINUX_RING_BUFFER_TYPES_H
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#include <asm/local.h>
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#define TS_SHIFT 27
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#define TS_MASK ((1ULL << TS_SHIFT) - 1)
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#define TS_DELTA_TEST (~TS_MASK)
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/*
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* We need to fit the time_stamp delta into 27 bits.
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*/
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static inline bool test_time_stamp(u64 delta)
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{
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return !!(delta & TS_DELTA_TEST);
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}
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#define BUF_PAGE_HDR_SIZE offsetof(struct buffer_data_page, data)
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#define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array))
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#define RB_ALIGNMENT 4U
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#define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
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#define RB_EVNT_MIN_SIZE 8U /* two 32bit words */
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#ifndef CONFIG_HAVE_64BIT_ALIGNED_ACCESS
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# define RB_FORCE_8BYTE_ALIGNMENT 0
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# define RB_ARCH_ALIGNMENT RB_ALIGNMENT
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#else
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# define RB_FORCE_8BYTE_ALIGNMENT 1
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# define RB_ARCH_ALIGNMENT 8U
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#endif
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#define RB_ALIGN_DATA __aligned(RB_ARCH_ALIGNMENT)
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struct buffer_data_page {
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u64 time_stamp; /* page time stamp */
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local_t commit; /* write committed index */
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unsigned char data[] RB_ALIGN_DATA; /* data of buffer page */
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};
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#endif
+1
-35
kernel/trace/ring_buffer.c
+1
-35
kernel/trace/ring_buffer.c
···
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*
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* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
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*/
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#include <linux/ring_buffer_types.h>
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#include <linux/sched/isolation.h>
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#include <linux/trace_recursion.h>
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#include <linux/trace_events.h>
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/* Used for individual buffers (after the counter) */
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#define RB_BUFFER_OFF (1 << 20)
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#define BUF_PAGE_HDR_SIZE offsetof(struct buffer_data_page, data)
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#define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array))
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#define RB_ALIGNMENT 4U
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#define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
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#define RB_EVNT_MIN_SIZE 8U /* two 32bit words */
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#ifndef CONFIG_HAVE_64BIT_ALIGNED_ACCESS
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# define RB_FORCE_8BYTE_ALIGNMENT 0
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# define RB_ARCH_ALIGNMENT RB_ALIGNMENT
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#else
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# define RB_FORCE_8BYTE_ALIGNMENT 1
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# define RB_ARCH_ALIGNMENT 8U
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#endif
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#define RB_ALIGN_DATA __aligned(RB_ARCH_ALIGNMENT)
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/* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */
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#define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX
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···
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#define for_each_online_buffer_cpu(buffer, cpu) \
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for_each_cpu_and(cpu, buffer->cpumask, cpu_online_mask)
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#define TS_SHIFT 27
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#define TS_MASK ((1ULL << TS_SHIFT) - 1)
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#define TS_DELTA_TEST (~TS_MASK)
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static u64 rb_event_time_stamp(struct ring_buffer_event *event)
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{
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u64 ts;
···
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#define RB_MISSED_STORED (1 << 30)
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#define RB_MISSED_MASK (3 << 30)
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struct buffer_data_page {
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u64 time_stamp; /* page time stamp */
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local_t commit; /* write committed index */
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unsigned char data[] RB_ALIGN_DATA; /* data of buffer page */
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};
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struct buffer_data_read_page {
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unsigned order; /* order of the page */
···
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rb_init_page(dpage);
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return dpage;
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}
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/*
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* We need to fit the time_stamp delta into 27 bits.
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*/
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static inline bool test_time_stamp(u64 delta)
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{
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return !!(delta & TS_DELTA_TEST);
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}
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struct rb_irq_work {