Steven Rostedt (Google) 8208c266fe ring-buffer: Include dropped pages in counting dirty patches ... [ Upstream commit 31029a8b2c7e656a0289194ef16415050ae4c4ac ] The function ring_buffer_nr_dirty_pages() was created to find out how many pages are filled in the ring buffer. There's two running counters. One is incremented whenever a new page is touched (pages_touched) and the other is whenever a page is read (pages_read). The dirty count is the number touched minus the number read. This is used to determine if a blocked task should be woken up if the percentage of the ring buffer it is waiting for is hit. The problem is that it does not take into account dropped pages (when the new writes overwrite pages that were not read). And then the dirty pages will always be greater than the percentage. This makes the "buffer_percent" file inaccurate, as the number of dirty pages end up always being larger than the percentage, event when it's not and this causes user space to be woken up more than it wants to be. Add a new counter to keep track of lost pages, and include that in the accounting of dirty pages so that it is actually accurate. Link: https://lkml.kernel.org/r/20221021123013.55fb6055@gandalf.local.home Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-11-25 17:45:54 +01:00
..
blktrace.c	blktrace: Trace remapped requests correctly	2022-08-21 15:15:36 +02:00
bpf_trace.c	bpf: Remove config check to enable bpf support for branch records	2022-01-27 10:53:54 +01:00
bpf_trace.h	bpf: Use dedicated bpf_trace_printk event instead of trace_printk()	2020-07-13 16:55:49 -07:00
fgraph.c	fgraph: Initialize tracing_graph_pause at task creation	2021-02-10 09:29:16 +01:00
ftrace_internal.h	x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up	2020-05-12 18:24:34 -04:00
ftrace.c	ftrace: Fix null pointer dereference in ftrace_add_mod()	2022-11-25 17:45:48 +01:00
Kconfig	tracing/kprobes: Do the notrace functions check without kprobes on ftrace	2021-01-19 18:27:19 +01:00
kprobe_event_gen_test.c	tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()	2022-11-25 17:45:49 +01:00
Makefile	Kbuild updates for v5.9	2020-08-09 14:10:26 -07:00
power-traces.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
preemptirq_delay_test.c	tracing: Wait for preempt irq delay thread to execute	2020-05-11 17:00:34 -04:00
ring_buffer_benchmark.c	sched,tracing: Convert to sched_set_fifo()	2020-07-29 11:43:53 +02:00
ring_buffer.c	ring-buffer: Include dropped pages in counting dirty patches	2022-11-25 17:45:54 +01:00
rpm-traces.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
synth_event_gen_test.c	tracing: Fix memory leak in test_gen_synth_cmd() and test_empty_synth_event()	2022-11-25 17:45:49 +01:00
trace_benchmark.c	trace: Use pr_warn instead of pr_warning	2019-10-18 15:01:57 +02:00
trace_benchmark.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_boot.c	tracing/boot: Fix a hist trigger dependency for boot time tracing	2021-09-22 12:28:03 +02:00
trace_branch.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_clock.c	tracing: Do no increment trace_clock_global() by one	2021-06-23 14:42:50 +02:00
trace_dynevent.c	tracing: Delete repeated words in comments	2020-09-21 21:06:02 -04:00
trace_dynevent.h	tracing: Remove check_arg() callbacks from dynevent args	2020-02-01 13:09:23 -05:00
trace_entries.h	tracing: Make ftrace packed events have align of 1	2020-06-16 21:21:02 -04:00
trace_event_perf.c	Merge branch 'perf/urgent' into perf/core, to pick up fixes	2019-10-28 12:38:26 +01:00
trace_events_filter_test.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_events_filter.c	tracing: Add ustring operation to filtering string pointers	2022-03-08 19:09:31 +01:00
trace_events_hist.c	tracing/histograms: Fix memory leak problem	2022-07-21 21:19:59 +02:00
trace_events_inject.c	tracing: Initialize val to zero in parse_entry of inject code	2020-01-02 19:04:57 -05:00
trace_events_synth.c	tracing: Fix wild-memory-access in register_synth_event()	2022-11-25 17:45:49 +01:00
trace_events_trigger.c	tracing: Dump stacktrace trigger to the corresponding instance	2022-04-27 13:53:46 +02:00
trace_events.c	tracing: Have filter accept "common_cpu" to be consistent	2022-08-25 11:37:51 +02:00
trace_export.c	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
trace_functions_graph.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_functions.c	tracing: Have all levels of checks prevent recursion	2021-10-27 09:56:56 +02:00
trace_hwlat.c	tracing: Remove WARN_ON in start_thread()	2020-11-30 21:43:07 -05:00
trace_irqsoff.c	tracing: Use pause-on-trace with the latency tracers	2021-02-10 09:29:16 +01:00
trace_kdb.c	tracing: Rename trace_buffer to array_buffer	2020-01-13 13:19:38 -05:00
trace_kprobe_selftest.c	selftest/ftrace: Move kprobe selftest function to separate compile unit	2018-07-30 18:41:04 -04:00
trace_kprobe_selftest.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_kprobe.c	tracing: Fix return value of __setup handlers	2022-03-08 19:09:38 +01:00
trace_mmiotrace.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_nop.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
trace_output.c	tracing: Make the space reserved for the pid wider	2020-09-18 12:42:11 -04:00
trace_output.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_preemptirq.c	tracing: hold caller_addr to hardirq_{enable,disable}_ip	2022-09-23 14:16:58 +02:00
trace_printk.c	Updates for tracing and bootconfig:	2020-10-15 15:51:28 -07:00
trace_probe_tmpl.h	tracing/probe: Support user-space dereference	2019-05-25 23:04:42 -04:00
trace_probe.c	tracing/probes: Have kprobes and uprobes use $COMM too	2022-08-25 11:38:23 +02:00
trace_probe.h	tracing/probes: Reject events which have the same name of existing one	2021-09-22 12:28:00 +02:00
trace_sched_switch.c	tracing: Fix sched switch start/stop refcount racy updates	2020-01-30 09:46:10 -05:00
trace_sched_wakeup.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_selftest_dynamic.c	ftrace: Mark function tracer test functions noinline/noclone	2018-01-23 15:57:29 -05:00
trace_selftest.c	tracing: Disable ftrace selftests when any tracer is running	2020-12-30 11:54:28 +01:00
trace_seq.c	tracing: Remove unused TRACE_SEQ_BUF_USED	2020-01-21 18:39:54 -05:00
trace_stack.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_stat.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_stat.h	tracing: Use generic type for comparator function	2019-11-14 13:15:11 -05:00
trace_synth.h	tracing: Synthetic event field_pos is an index not a boolean	2021-07-28 14:35:45 +02:00
trace_syscalls.c	Tracing updates:	2020-02-06 07:12:11 +00:00
trace_uprobe.c	tracing/uprobe: Fix uprobe_perf_open probes iteration	2021-12-01 09:19:01 +01:00
trace.c	tracing/ring-buffer: Have polling block on watermark	2022-11-25 17:45:49 +01:00
trace.h	tracing: Fix pid filtering when triggers are attached	2021-12-01 09:19:01 +01:00
tracing_map.c	tracing: Fix a kmemleak false positive in tracing_map	2021-12-17 10:14:40 +01:00
tracing_map.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00