lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 30 Nov 2010 18:10:53 -0200
From:	Arnaldo Carvalho de Melo <acme@...radead.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>,
	Peter Zijlstra <peterz@...radead.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 08/11] perf session: Keep file mmaped instead of malloc/memcpy

From: Thomas Gleixner <tglx@...utronix.de>

Profiling perf with perf revealed that a large part of the processing time is
spent in malloc/memcpy/free in the sample ordering code. That code copies the
data from the mmap into malloc'ed memory. That's silly. We can keep the mmap
and just store the pointer in the queuing data structure. For 64 bit this is
not a problem as we map the whole file anyway. On 32bit we keep 8 maps around
and unmap the oldest before mmaping the next chunk of the file.

Performance gain: 2.95s -> 1.23s (Faktor 2.4)

Cc: Ingo Molnar <mingo@...e.hu>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>
LKML-Reference: <20101130163820.278787719@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/session.c |   27 +++++++++++----------------
 1 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 752577f..c989583 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -418,7 +418,6 @@ static void flush_sample_queue(struct perf_session *s,
 
 		os->last_flush = iter->timestamp;
 		list_del(&iter->list);
-		free(iter->event);
 		free(iter);
 	}
 
@@ -531,7 +530,6 @@ static int queue_sample_event(event_t *event, struct sample_data *data,
 	u64 timestamp = data->time;
 	struct sample_queue *new;
 
-
 	if (timestamp < s->ordered_samples.last_flush) {
 		printf("Warning: Timestamp below last timeslice flush\n");
 		return -EINVAL;
@@ -542,14 +540,7 @@ static int queue_sample_event(event_t *event, struct sample_data *data,
 		return -ENOMEM;
 
 	new->timestamp = timestamp;
-
-	new->event = malloc(event->header.size);
-	if (!new->event) {
-		free(new);
-		return -ENOMEM;
-	}
-
-	memcpy(new->event, event, event->header.size);
+	new->event = event;
 
 	__queue_sample_event(new, s);
 
@@ -747,12 +738,12 @@ int __perf_session__process_events(struct perf_session *session,
 				   u64 file_size, struct perf_event_ops *ops)
 {
 	u64 head, page_offset, file_offset, file_pos, progress_next;
-	int err, mmap_prot, mmap_flags;
+	int err, mmap_prot, mmap_flags, map_idx = 0;
 	struct ui_progress *progress;
 	size_t	page_size, mmap_size;
+	char *buf, *mmaps[8];
 	event_t *event;
 	uint32_t size;
-	char *buf;
 
 	perf_event_ops__fill_defaults(ops);
 
@@ -774,6 +765,8 @@ int __perf_session__process_events(struct perf_session *session,
 	if (mmap_size > file_size)
 		mmap_size = file_size;
 
+	memset(mmaps, 0, sizeof(mmaps));
+
 	mmap_prot  = PROT_READ;
 	mmap_flags = MAP_SHARED;
 
@@ -789,6 +782,8 @@ remap:
 		err = -errno;
 		goto out_err;
 	}
+	mmaps[map_idx] = buf;
+	map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
 	file_pos = file_offset + head;
 
 more:
@@ -801,10 +796,10 @@ more:
 		size = 8;
 
 	if (head + event->header.size >= mmap_size) {
-		int munmap_ret;
-
-		munmap_ret = munmap(buf, mmap_size);
-		assert(munmap_ret == 0);
+		if (mmaps[map_idx]) {
+			munmap(mmaps[map_idx], mmap_size);
+			mmaps[map_idx] = NULL;
+		}
 
 		page_offset = page_size * (head / page_size);
 		file_offset += page_offset;
-- 
1.6.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists