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authorLinus Torvalds <torvalds@linux-foundation.org>2024-01-09 22:18:47 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-01-09 22:18:47 +0300
commitfb46e22a9e3863e08aef8815df9f17d0f4b9aede (patch)
tree83e052911fa8d8d90bcf9de2796e17e19040613f /samples
parentd30e51aa7b1f6fa7dd78d4598d1e4c047fcc3fb9 (diff)
parent5e0a760b44417f7cadd79de2204d6247109558a0 (diff)
downloadlinux-fb46e22a9e3863e08aef8815df9f17d0f4b9aede.tar.xz
Merge tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...
Diffstat (limited to 'samples')
-rw-r--r--samples/Kconfig6
-rw-r--r--samples/Makefile1
-rw-r--r--samples/cgroup/Makefile5
-rw-r--r--samples/cgroup/cgroup_event_listener.c83
-rw-r--r--samples/cgroup/memcg_event_listener.c330
5 files changed, 425 insertions, 0 deletions
diff --git a/samples/Kconfig b/samples/Kconfig
index b0ddf5f36738..b288d9991d27 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -285,6 +285,12 @@ config SAMPLE_KMEMLEAK
Build a sample program which have explicitly leaks memory to test
kmemleak
+config SAMPLE_CGROUP
+ bool "Build cgroup sample code"
+ depends on CGROUPS && CC_CAN_LINK && HEADERS_INSTALL
+ help
+ Build samples that demonstrate the usage of the cgroup API.
+
source "samples/rust/Kconfig"
endif # SAMPLES
diff --git a/samples/Makefile b/samples/Makefile
index 0a551c2b33f4..b85fa64390c5 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -3,6 +3,7 @@
subdir-$(CONFIG_SAMPLE_AUXDISPLAY) += auxdisplay
subdir-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs
+subdir-$(CONFIG_SAMPLE_CGROUP) += cgroup
obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs/
obj-$(CONFIG_SAMPLE_CONNECTOR) += connector/
obj-$(CONFIG_SAMPLE_FANOTIFY_ERROR) += fanotify/
diff --git a/samples/cgroup/Makefile b/samples/cgroup/Makefile
new file mode 100644
index 000000000000..526c8569707c
--- /dev/null
+++ b/samples/cgroup/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+userprogs-always-y += cgroup_event_listener memcg_event_listener
+
+userccflags += -I usr/include
diff --git a/samples/cgroup/cgroup_event_listener.c b/samples/cgroup/cgroup_event_listener.c
new file mode 100644
index 000000000000..3d70dc831a76
--- /dev/null
+++ b/samples/cgroup/cgroup_event_listener.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cgroup_event_listener.c - Simple listener of cgroup events
+ *
+ * Copyright (C) Kirill A. Shutemov <kirill@shutemov.name>
+ */
+
+#include <assert.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/eventfd.h>
+
+#define USAGE_STR "Usage: cgroup_event_listener <path-to-control-file> <args>"
+
+int main(int argc, char **argv)
+{
+ int efd = -1;
+ int cfd = -1;
+ int event_control = -1;
+ char event_control_path[PATH_MAX];
+ char line[LINE_MAX];
+ int ret;
+
+ if (argc != 3)
+ errx(1, "%s", USAGE_STR);
+
+ cfd = open(argv[1], O_RDONLY);
+ if (cfd == -1)
+ err(1, "Cannot open %s", argv[1]);
+
+ ret = snprintf(event_control_path, PATH_MAX, "%s/cgroup.event_control",
+ dirname(argv[1]));
+ if (ret >= PATH_MAX)
+ errx(1, "Path to cgroup.event_control is too long");
+
+ event_control = open(event_control_path, O_WRONLY);
+ if (event_control == -1)
+ err(1, "Cannot open %s", event_control_path);
+
+ efd = eventfd(0, 0);
+ if (efd == -1)
+ err(1, "eventfd() failed");
+
+ ret = snprintf(line, LINE_MAX, "%d %d %s", efd, cfd, argv[2]);
+ if (ret >= LINE_MAX)
+ errx(1, "Arguments string is too long");
+
+ ret = write(event_control, line, strlen(line) + 1);
+ if (ret == -1)
+ err(1, "Cannot write to cgroup.event_control");
+
+ while (1) {
+ uint64_t result;
+
+ ret = read(efd, &result, sizeof(result));
+ if (ret == -1) {
+ if (errno == EINTR)
+ continue;
+ err(1, "Cannot read from eventfd");
+ }
+ assert(ret == sizeof(result));
+
+ ret = access(event_control_path, W_OK);
+ if ((ret == -1) && (errno == ENOENT)) {
+ puts("The cgroup seems to have removed.");
+ break;
+ }
+
+ if (ret == -1)
+ err(1, "cgroup.event_control is not accessible any more");
+
+ printf("%s %s: crossed\n", argv[1], argv[2]);
+ }
+
+ return 0;
+}
diff --git a/samples/cgroup/memcg_event_listener.c b/samples/cgroup/memcg_event_listener.c
new file mode 100644
index 000000000000..a1667fe2489a
--- /dev/null
+++ b/samples/cgroup/memcg_event_listener.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * memcg_event_listener.c - Simple listener of memcg memory.events
+ *
+ * Copyright (c) 2023, SaluteDevices. All Rights Reserved.
+ *
+ * Author: Dmitry Rokosov <ddrokosov@salutedevices.com>
+ */
+
+#include <err.h>
+#include <errno.h>
+#include <limits.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/inotify.h>
+#include <unistd.h>
+
+#define MEMCG_EVENTS "memory.events"
+
+/* Size of buffer to use when reading inotify events */
+#define INOTIFY_BUFFER_SIZE 8192
+
+#define INOTIFY_EVENT_NEXT(event, length) ({ \
+ (length) -= sizeof(*(event)) + (event)->len; \
+ (event)++; \
+})
+
+#define INOTIFY_EVENT_OK(event, length) ((length) >= (ssize_t)sizeof(*(event)))
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
+
+struct memcg_counters {
+ long low;
+ long high;
+ long max;
+ long oom;
+ long oom_kill;
+ long oom_group_kill;
+};
+
+struct memcg_events {
+ struct memcg_counters counters;
+ char path[PATH_MAX];
+ int inotify_fd;
+ int inotify_wd;
+};
+
+static void print_memcg_counters(const struct memcg_counters *counters)
+{
+ printf("MEMCG events:\n");
+ printf("\tlow: %ld\n", counters->low);
+ printf("\thigh: %ld\n", counters->high);
+ printf("\tmax: %ld\n", counters->max);
+ printf("\toom: %ld\n", counters->oom);
+ printf("\toom_kill: %ld\n", counters->oom_kill);
+ printf("\toom_group_kill: %ld\n", counters->oom_group_kill);
+}
+
+static int get_memcg_counter(char *line, const char *name, long *counter)
+{
+ size_t len = strlen(name);
+ char *endptr;
+ long tmp;
+
+ if (memcmp(line, name, len)) {
+ warnx("Counter line %s has wrong name, %s is expected",
+ line, name);
+ return -EINVAL;
+ }
+
+ /* skip the whitespace delimiter */
+ len += 1;
+
+ errno = 0;
+ tmp = strtol(&line[len], &endptr, 10);
+ if (((tmp == LONG_MAX || tmp == LONG_MIN) && errno == ERANGE) ||
+ (errno && !tmp)) {
+ warnx("Failed to parse: %s", &line[len]);
+ return -ERANGE;
+ }
+
+ if (endptr == &line[len]) {
+ warnx("Not digits were found in line %s", &line[len]);
+ return -EINVAL;
+ }
+
+ if (!(*endptr == '\0' || (*endptr == '\n' && *++endptr == '\0'))) {
+ warnx("Further characters after number: %s", endptr);
+ return -EINVAL;
+ }
+
+ *counter = tmp;
+
+ return 0;
+}
+
+static int read_memcg_events(struct memcg_events *events, bool show_diff)
+{
+ FILE *fp = fopen(events->path, "re");
+ size_t i;
+ int ret = 0;
+ bool any_new_events = false;
+ char *line = NULL;
+ size_t len = 0;
+ struct memcg_counters new_counters;
+ struct memcg_counters *counters = &events->counters;
+ struct {
+ const char *name;
+ long *new;
+ long *old;
+ } map[] = {
+ {
+ .name = "low",
+ .new = &new_counters.low,
+ .old = &counters->low,
+ },
+ {
+ .name = "high",
+ .new = &new_counters.high,
+ .old = &counters->high,
+ },
+ {
+ .name = "max",
+ .new = &new_counters.max,
+ .old = &counters->max,
+ },
+ {
+ .name = "oom",
+ .new = &new_counters.oom,
+ .old = &counters->oom,
+ },
+ {
+ .name = "oom_kill",
+ .new = &new_counters.oom_kill,
+ .old = &counters->oom_kill,
+ },
+ {
+ .name = "oom_group_kill",
+ .new = &new_counters.oom_group_kill,
+ .old = &counters->oom_group_kill,
+ },
+ };
+
+ if (!fp) {
+ warn("Failed to open memcg events file %s", events->path);
+ return -EBADF;
+ }
+
+ /* Read new values for memcg counters */
+ for (i = 0; i < ARRAY_SIZE(map); ++i) {
+ ssize_t nread;
+
+ errno = 0;
+ nread = getline(&line, &len, fp);
+ if (nread == -1) {
+ if (errno) {
+ warn("Failed to read line for counter %s",
+ map[i].name);
+ ret = -EIO;
+ goto exit;
+ }
+
+ break;
+ }
+
+ ret = get_memcg_counter(line, map[i].name, map[i].new);
+ if (ret) {
+ warnx("Failed to get counter value from line %s", line);
+ goto exit;
+ }
+ }
+
+ for (i = 0; i < ARRAY_SIZE(map); ++i) {
+ long diff;
+
+ if (*map[i].new > *map[i].old) {
+ diff = *map[i].new - *map[i].old;
+
+ if (show_diff)
+ printf("*** %ld MEMCG %s event%s, "
+ "change counter %ld => %ld\n",
+ diff, map[i].name,
+ (diff == 1) ? "" : "s",
+ *map[i].old, *map[i].new);
+
+ *map[i].old += diff;
+ any_new_events = true;
+ }
+ }
+
+ if (show_diff && !any_new_events)
+ printf("*** No new untracked memcg events available\n");
+
+exit:
+ free(line);
+ fclose(fp);
+
+ return ret;
+}
+
+static void process_memcg_events(struct memcg_events *events,
+ struct inotify_event *event)
+{
+ int ret;
+
+ if (events->inotify_wd != event->wd) {
+ warnx("Unknown inotify event %d, should be %d", event->wd,
+ events->inotify_wd);
+ return;
+ }
+
+ printf("Received event in %s:\n", events->path);
+
+ if (!(event->mask & IN_MODIFY)) {
+ warnx("No IN_MODIFY event, skip it");
+ return;
+ }
+
+ ret = read_memcg_events(events, /* show_diff = */true);
+ if (ret)
+ warnx("Can't read memcg events");
+}
+
+static void monitor_events(struct memcg_events *events)
+{
+ struct pollfd fds[1];
+ int ret;
+
+ printf("Started monitoring memory events from '%s'...\n", events->path);
+
+ fds[0].fd = events->inotify_fd;
+ fds[0].events = POLLIN;
+
+ for (;;) {
+ ret = poll(fds, ARRAY_SIZE(fds), -1);
+ if (ret < 0 && errno != EAGAIN)
+ err(EXIT_FAILURE, "Can't poll memcg events (%d)", ret);
+
+ if (fds[0].revents & POLLERR)
+ err(EXIT_FAILURE, "Got POLLERR during monitor events");
+
+ if (fds[0].revents & POLLIN) {
+ struct inotify_event *event;
+ char buffer[INOTIFY_BUFFER_SIZE];
+ ssize_t length;
+
+ length = read(fds[0].fd, buffer, INOTIFY_BUFFER_SIZE);
+ if (length <= 0)
+ continue;
+
+ event = (struct inotify_event *)buffer;
+ while (INOTIFY_EVENT_OK(event, length)) {
+ process_memcg_events(events, event);
+ event = INOTIFY_EVENT_NEXT(event, length);
+ }
+ }
+ }
+}
+
+static int initialize_memcg_events(struct memcg_events *events,
+ const char *cgroup)
+{
+ int ret;
+
+ memset(events, 0, sizeof(struct memcg_events));
+
+ ret = snprintf(events->path, PATH_MAX,
+ "/sys/fs/cgroup/%s/memory.events", cgroup);
+ if (ret >= PATH_MAX) {
+ warnx("Path to cgroup memory.events is too long");
+ return -EMSGSIZE;
+ } else if (ret < 0) {
+ warn("Can't generate cgroup event full name");
+ return ret;
+ }
+
+ ret = read_memcg_events(events, /* show_diff = */false);
+ if (ret) {
+ warnx("Failed to read initial memcg events state (%d)", ret);
+ return ret;
+ }
+
+ events->inotify_fd = inotify_init();
+ if (events->inotify_fd < 0) {
+ warn("Failed to setup new inotify device");
+ return -EMFILE;
+ }
+
+ events->inotify_wd = inotify_add_watch(events->inotify_fd,
+ events->path, IN_MODIFY);
+ if (events->inotify_wd < 0) {
+ warn("Couldn't add monitor in dir %s", events->path);
+ return -EIO;
+ }
+
+ printf("Initialized MEMCG events with counters:\n");
+ print_memcg_counters(&events->counters);
+
+ return 0;
+}
+
+static void cleanup_memcg_events(struct memcg_events *events)
+{
+ inotify_rm_watch(events->inotify_fd, events->inotify_wd);
+ close(events->inotify_fd);
+}
+
+int main(int argc, const char **argv)
+{
+ struct memcg_events events;
+ ssize_t ret;
+
+ if (argc != 2)
+ errx(EXIT_FAILURE, "Usage: %s <cgroup>", argv[0]);
+
+ ret = initialize_memcg_events(&events, argv[1]);
+ if (ret)
+ errx(EXIT_FAILURE, "Can't initialize memcg events (%zd)", ret);
+
+ monitor_events(&events);
+
+ cleanup_memcg_events(&events);
+
+ printf("Exiting memcg event listener...\n");
+
+ return EXIT_SUCCESS;
+}