Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 646 insertions, 0 deletions

diff --git a/src/oom/oomd-util.c b/src/oom/oomd-util.c
new file mode 100644
index 0000000..391d846
--- /dev/null
+++ b/src/oom/oomd-util.c
@@ -0,0 +1,646 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <sys/xattr.h>
+#include <unistd.h>
+
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "oomd-util.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "procfs-util.h"
+#include "signal-util.h"
+#include "sort-util.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "user-util.h"
+
+DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
+                oomd_cgroup_ctx_hash_ops,
+                char,
+                string_hash_func,
+                string_compare_func,
+                OomdCGroupContext,
+                oomd_cgroup_context_free);
+
+static int log_kill(pid_t pid, int sig, void *userdata) {
+        log_debug("oomd attempting to kill " PID_FMT " with %s", pid, signal_to_string(sig));
+        return 0;
+}
+
+static int increment_oomd_xattr(const char *path, const char *xattr, uint64_t num_procs_killed) {
+        _cleanup_free_ char *value = NULL;
+        char buf[DECIMAL_STR_MAX(uint64_t) + 1];
+        uint64_t curr_count = 0;
+        int r;
+
+        assert(path);
+        assert(xattr);
+
+        r = cg_get_xattr_malloc(SYSTEMD_CGROUP_CONTROLLER, path, xattr, &value);
+        if (r < 0 && !ERRNO_IS_XATTR_ABSENT(r))
+                return r;
+
+        if (!isempty(value)) {
+                 r = safe_atou64(value, &curr_count);
+                 if (r < 0)
+                         return r;
+        }
+
+        if (curr_count > UINT64_MAX - num_procs_killed)
+                return -EOVERFLOW;
+
+        xsprintf(buf, "%"PRIu64, curr_count + num_procs_killed);
+        r = cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, path, xattr, buf, strlen(buf), 0);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+OomdCGroupContext *oomd_cgroup_context_free(OomdCGroupContext *ctx) {
+        if (!ctx)
+                return NULL;
+
+        free(ctx->path);
+        return mfree(ctx);
+}
+
+int oomd_pressure_above(Hashmap *h, usec_t duration, Set **ret) {
+        _cleanup_set_free_ Set *targets = NULL;
+        OomdCGroupContext *ctx;
+        char *key;
+        int r;
+
+        assert(h);
+        assert(ret);
+
+        targets = set_new(NULL);
+        if (!targets)
+                return -ENOMEM;
+
+        HASHMAP_FOREACH_KEY(ctx, key, h) {
+                if (ctx->memory_pressure.avg10 > ctx->mem_pressure_limit) {
+                        usec_t diff;
+
+                        if (ctx->mem_pressure_limit_hit_start == 0)
+                                ctx->mem_pressure_limit_hit_start = now(CLOCK_MONOTONIC);
+
+                        diff = now(CLOCK_MONOTONIC) - ctx->mem_pressure_limit_hit_start;
+                        if (diff >= duration) {
+                                r = set_put(targets, ctx);
+                                if (r < 0)
+                                        return -ENOMEM;
+                        }
+                } else
+                        ctx->mem_pressure_limit_hit_start = 0;
+        }
+
+        if (!set_isempty(targets)) {
+                *ret = TAKE_PTR(targets);
+                return 1;
+        }
+
+        *ret = NULL;
+        return 0;
+}
+
+uint64_t oomd_pgscan_rate(const OomdCGroupContext *c) {
+        uint64_t last_pgscan;
+
+        assert(c);
+
+        /* If last_pgscan > pgscan, assume the cgroup was recreated and reset last_pgscan to zero.
+         * pgscan is monotonic and in practice should not decrease (except in the recreation case). */
+        last_pgscan = c->last_pgscan;
+        if (c->last_pgscan > c->pgscan) {
+                log_debug("Last pgscan %"PRIu64" greater than current pgscan %"PRIu64" for %s. Using last pgscan of zero.",
+                                c->last_pgscan, c->pgscan, c->path);
+                last_pgscan = 0;
+        }
+
+        return c->pgscan - last_pgscan;
+}
+
+bool oomd_mem_available_below(const OomdSystemContext *ctx, int threshold_permyriad) {
+        uint64_t mem_threshold;
+
+        assert(ctx);
+        assert(threshold_permyriad <= 10000);
+
+        mem_threshold = ctx->mem_total * threshold_permyriad / (uint64_t) 10000;
+        return LESS_BY(ctx->mem_total, ctx->mem_used) < mem_threshold;
+}
+
+bool oomd_swap_free_below(const OomdSystemContext *ctx, int threshold_permyriad) {
+        uint64_t swap_threshold;
+
+        assert(ctx);
+        assert(threshold_permyriad <= 10000);
+
+        swap_threshold = ctx->swap_total * threshold_permyriad / (uint64_t) 10000;
+        return (ctx->swap_total - ctx->swap_used) < swap_threshold;
+}
+
+int oomd_fetch_cgroup_oom_preference(OomdCGroupContext *ctx, const char *prefix) {
+        uid_t uid, prefix_uid;
+        int r;
+
+        assert(ctx);
+
+        prefix = empty_to_root(prefix);
+
+        if (!path_startswith(ctx->path, prefix))
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "%s is not a descendant of %s", ctx->path, prefix);
+
+        r = cg_get_owner(SYSTEMD_CGROUP_CONTROLLER, ctx->path, &uid);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to get owner/group from %s: %m", ctx->path);
+
+        r = cg_get_owner(SYSTEMD_CGROUP_CONTROLLER, prefix, &prefix_uid);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to get owner/group from %s: %m", ctx->path);
+
+        if (uid == prefix_uid || uid == 0) {
+                /* Ignore most errors when reading the xattr since it is usually unset and cgroup xattrs are only used
+                 * as an optional feature of systemd-oomd (and the system might not even support them). */
+                r = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, ctx->path, "user.oomd_avoid");
+                if (r == -ENOMEM)
+                        return log_oom_debug();
+                if (r < 0 && !ERRNO_IS_XATTR_ABSENT(r))
+                        log_debug_errno(r, "Failed to get xattr user.oomd_avoid, ignoring: %m");
+                ctx->preference = r > 0 ? MANAGED_OOM_PREFERENCE_AVOID : ctx->preference;
+
+                r = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, ctx->path, "user.oomd_omit");
+                if (r == -ENOMEM)
+                        return log_oom_debug();
+                if (r < 0 && !ERRNO_IS_XATTR_ABSENT(r))
+                        log_debug_errno(r, "Failed to get xattr user.oomd_omit, ignoring: %m");
+                ctx->preference = r > 0 ? MANAGED_OOM_PREFERENCE_OMIT : ctx->preference;
+        } else
+                ctx->preference = MANAGED_OOM_PREFERENCE_NONE;
+
+        return 0;
+}
+
+int oomd_sort_cgroup_contexts(Hashmap *h, oomd_compare_t compare_func, const char *prefix, OomdCGroupContext ***ret) {
+        _cleanup_free_ OomdCGroupContext **sorted = NULL;
+        OomdCGroupContext *item;
+        size_t k = 0;
+        int r;
+
+        assert(h);
+        assert(compare_func);
+        assert(ret);
+
+        sorted = new0(OomdCGroupContext*, hashmap_size(h));
+        if (!sorted)
+                return -ENOMEM;
+
+        HASHMAP_FOREACH(item, h) {
+                /* Skip over cgroups that are not valid candidates or are explicitly marked for omission */
+                if (item->path && prefix && !path_startswith(item->path, prefix))
+                        continue;
+
+                r = oomd_fetch_cgroup_oom_preference(item, prefix);
+                if (r == -ENOMEM)
+                        return r;
+
+                if (item->preference == MANAGED_OOM_PREFERENCE_OMIT)
+                        continue;
+
+                sorted[k++] = item;
+        }
+
+        typesafe_qsort(sorted, k, compare_func);
+
+        *ret = TAKE_PTR(sorted);
+
+        assert(k <= INT_MAX);
+        return (int) k;
+}
+
+int oomd_cgroup_kill(const char *path, bool recurse, bool dry_run) {
+        _cleanup_set_free_ Set *pids_killed = NULL;
+        int r;
+
+        assert(path);
+
+        if (dry_run) {
+                _cleanup_free_ char *cg_path = NULL;
+
+                r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &cg_path);
+                if (r < 0)
+                        return r;
+
+                log_info("oomd dry-run: Would have tried to kill %s with recurse=%s", cg_path, true_false(recurse));
+                return 0;
+        }
+
+        pids_killed = set_new(NULL);
+        if (!pids_killed)
+                return -ENOMEM;
+
+        r = increment_oomd_xattr(path, "user.oomd_ooms", 1);
+        if (r < 0)
+                log_debug_errno(r, "Failed to set user.oomd_ooms before kill: %m");
+
+        if (recurse)
+                r = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, path, SIGKILL, CGROUP_IGNORE_SELF, pids_killed, log_kill, NULL);
+        else
+                r = cg_kill(SYSTEMD_CGROUP_CONTROLLER, path, SIGKILL, CGROUP_IGNORE_SELF, pids_killed, log_kill, NULL);
+
+        /* The cgroup could have been cleaned up after we have sent SIGKILL to all of the processes, but before
+         * we could do one last iteration of cgroup.procs to check. Or the service unit could have exited and
+         * was removed between picking candidates and coming into this function. In either case, let's log
+         * about it let the caller decide what to do once they know how many PIDs were killed. */
+        if (IN_SET(r, -ENOENT, -ENODEV))
+                log_debug_errno(r, "Error when sending SIGKILL to processes in cgroup path %s, ignoring: %m", path);
+        else if (r < 0)
+                return r;
+
+        if (set_isempty(pids_killed))
+                log_debug("Nothing killed when attempting to kill %s", path);
+
+        r = increment_oomd_xattr(path, "user.oomd_kill", set_size(pids_killed));
+        if (r < 0)
+                log_debug_errno(r, "Failed to set user.oomd_kill on kill: %m");
+
+        return set_size(pids_killed) != 0;
+}
+
+typedef void (*dump_candidate_func)(const OomdCGroupContext *ctx, FILE *f, const char *prefix);
+
+static int dump_kill_candidates(OomdCGroupContext **sorted, int n, int dump_until, dump_candidate_func dump_func) {
+        /* Try dumping top offendors, ignoring any errors that might happen. */
+        _cleanup_free_ char *dump = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+        size_t size;
+
+        f = open_memstream_unlocked(&dump, &size);
+        if (!f)
+                return -errno;
+
+        fprintf(f, "Considered %d cgroups for killing, top candidates were:\n", n);
+        for (int i = 0; i < dump_until; i++)
+                dump_func(sorted[i], f, "\t");
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return r;
+
+        return log_dump(LOG_INFO, dump);
+}
+
+int oomd_kill_by_pgscan_rate(Hashmap *h, const char *prefix, bool dry_run, char **ret_selected) {
+        _cleanup_free_ OomdCGroupContext **sorted = NULL;
+        int n, r, ret = 0;
+        int dump_until;
+
+        assert(h);
+        assert(ret_selected);
+
+        n = oomd_sort_cgroup_contexts(h, compare_pgscan_rate_and_memory_usage, prefix, &sorted);
+        if (n < 0)
+                return n;
+
+        dump_until = MIN(n, DUMP_ON_KILL_COUNT);
+        for (int i = 0; i < n; i++) {
+                /* Skip cgroups with no reclaim and memory usage; it won't alleviate pressure.
+                 * Continue since there might be "avoid" cgroups at the end. */
+                if (sorted[i]->pgscan == 0 && sorted[i]->current_memory_usage == 0)
+                        continue;
+
+                r = oomd_cgroup_kill(sorted[i]->path, /* recurse= */ true, /* dry_run= */ dry_run);
+                if (r == -ENOMEM)
+                        return r; /* Treat oom as a hard error */
+                if (r < 0) {
+                        if (ret == 0)
+                                ret = r;
+                        continue; /* Try to find something else to kill */
+                }
+
+                dump_until = MAX(dump_until, i + 1);
+                char *selected = strdup(sorted[i]->path);
+                if (!selected)
+                        return -ENOMEM;
+                *ret_selected = selected;
+                ret = r;
+                break;
+        }
+
+        dump_kill_candidates(sorted, n, dump_until, oomd_dump_memory_pressure_cgroup_context);
+
+        return ret;
+}
+
+int oomd_kill_by_swap_usage(Hashmap *h, uint64_t threshold_usage, bool dry_run, char **ret_selected) {
+        _cleanup_free_ OomdCGroupContext **sorted = NULL;
+        int n, r, ret = 0;
+        int dump_until;
+
+        assert(h);
+        assert(ret_selected);
+
+        n = oomd_sort_cgroup_contexts(h, compare_swap_usage, NULL, &sorted);
+        if (n < 0)
+                return n;
+
+        dump_until = MIN(n, DUMP_ON_KILL_COUNT);
+        /* Try to kill cgroups with non-zero swap usage until we either succeed in killing or we get to a cgroup with
+         * no swap usage. Threshold killing only cgroups with more than threshold swap usage. */
+        for (int i = 0; i < n; i++) {
+                /* Skip over cgroups with not enough swap usage. Don't break since there might be "avoid"
+                 * cgroups at the end. */
+                if (sorted[i]->swap_usage <= threshold_usage)
+                        continue;
+
+                r = oomd_cgroup_kill(sorted[i]->path, /* recurse= */ true, /* dry_run= */ dry_run);
+                if (r == -ENOMEM)
+                        return r; /* Treat oom as a hard error */
+                if (r < 0) {
+                        if (ret == 0)
+                                ret = r;
+                        continue; /* Try to find something else to kill */
+                }
+
+                dump_until = MAX(dump_until, i + 1);
+                char *selected = strdup(sorted[i]->path);
+                if (!selected)
+                        return -ENOMEM;
+                *ret_selected = selected;
+                ret = r;
+                break;
+        }
+
+        dump_kill_candidates(sorted, n, dump_until, oomd_dump_swap_cgroup_context);
+
+        return ret;
+}
+
+int oomd_cgroup_context_acquire(const char *path, OomdCGroupContext **ret) {
+        _cleanup_(oomd_cgroup_context_freep) OomdCGroupContext *ctx = NULL;
+        _cleanup_free_ char *p = NULL, *val = NULL;
+        bool is_root;
+        int r;
+
+        assert(path);
+        assert(ret);
+
+        ctx = new0(OomdCGroupContext, 1);
+        if (!ctx)
+                return -ENOMEM;
+
+        is_root = empty_or_root(path);
+        ctx->preference = MANAGED_OOM_PREFERENCE_NONE;
+
+        r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, "memory.pressure", &p);
+        if (r < 0)
+                return log_debug_errno(r, "Error getting cgroup memory pressure path from %s: %m", path);
+
+        r = read_resource_pressure(p, PRESSURE_TYPE_FULL, &ctx->memory_pressure);
+        if (r < 0)
+                return log_debug_errno(r, "Error parsing memory pressure from %s: %m", p);
+
+        if (is_root) {
+                r = procfs_memory_get_used(&ctx->current_memory_usage);
+                if (r < 0)
+                        return log_debug_errno(r, "Error getting memory used from procfs: %m");
+        } else {
+                r = cg_get_attribute_as_uint64(SYSTEMD_CGROUP_CONTROLLER, path, "memory.current", &ctx->current_memory_usage);
+                if (r < 0)
+                        return log_debug_errno(r, "Error getting memory.current from %s: %m", path);
+
+                r = cg_get_attribute_as_uint64(SYSTEMD_CGROUP_CONTROLLER, path, "memory.min", &ctx->memory_min);
+                if (r < 0)
+                        return log_debug_errno(r, "Error getting memory.min from %s: %m", path);
+
+                r = cg_get_attribute_as_uint64(SYSTEMD_CGROUP_CONTROLLER, path, "memory.low", &ctx->memory_low);
+                if (r < 0)
+                        return log_debug_errno(r, "Error getting memory.low from %s: %m", path);
+
+                r = cg_get_attribute_as_uint64(SYSTEMD_CGROUP_CONTROLLER, path, "memory.swap.current", &ctx->swap_usage);
+                if (r == -ENODATA)
+                        /* The kernel can be compiled without support for memory.swap.* files,
+                         * or it can be disabled with boot param 'swapaccount=0' */
+                        log_once(LOG_WARNING, "No kernel support for memory.swap.current from %s (try boot param swapaccount=1), ignoring.", path);
+                else if (r < 0)
+                        return log_debug_errno(r, "Error getting memory.swap.current from %s: %m", path);
+
+                r = cg_get_keyed_attribute(SYSTEMD_CGROUP_CONTROLLER, path, "memory.stat", STRV_MAKE("pgscan"), &val);
+                if (r < 0)
+                        return log_debug_errno(r, "Error getting pgscan from memory.stat under %s: %m", path);
+
+                r = safe_atou64(val, &ctx->pgscan);
+                if (r < 0)
+                        return log_debug_errno(r, "Error converting pgscan value to uint64_t: %m");
+        }
+
+        ctx->path = strdup(empty_to_root(path));
+        if (!ctx->path)
+                return -ENOMEM;
+
+        *ret = TAKE_PTR(ctx);
+        return 0;
+}
+
+int oomd_system_context_acquire(const char *proc_meminfo_path, OomdSystemContext *ret) {
+        _cleanup_fclose_ FILE *f = NULL;
+        unsigned field_filled = 0;
+        OomdSystemContext ctx = {};
+        uint64_t mem_available, swap_free;
+        int r;
+
+        enum {
+                MEM_TOTAL = 1U << 0,
+                MEM_AVAILABLE = 1U << 1,
+                SWAP_TOTAL = 1U << 2,
+                SWAP_FREE = 1U << 3,
+                ALL = MEM_TOTAL|MEM_AVAILABLE|SWAP_TOTAL|SWAP_FREE,
+        };
+
+        assert(proc_meminfo_path);
+        assert(ret);
+
+        f = fopen(proc_meminfo_path, "re");
+        if (!f)
+                return -errno;
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                char *word;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -EINVAL;
+
+                if ((word = startswith(line, "MemTotal:"))) {
+                        field_filled |= MEM_TOTAL;
+                        r = convert_meminfo_value_to_uint64_bytes(word, &ctx.mem_total);
+                } else if ((word = startswith(line, "MemAvailable:"))) {
+                        field_filled |= MEM_AVAILABLE;
+                        r = convert_meminfo_value_to_uint64_bytes(word, &mem_available);
+                } else if ((word = startswith(line, "SwapTotal:"))) {
+                        field_filled |= SWAP_TOTAL;
+                        r = convert_meminfo_value_to_uint64_bytes(word, &ctx.swap_total);
+                } else if ((word = startswith(line, "SwapFree:"))) {
+                        field_filled |= SWAP_FREE;
+                        r = convert_meminfo_value_to_uint64_bytes(word, &swap_free);
+                } else
+                        continue;
+
+                if (r < 0)
+                        return log_debug_errno(r, "Error converting '%s' from %s to uint64_t: %m", line, proc_meminfo_path);
+
+                if (field_filled == ALL)
+                        break;
+        }
+
+        if (field_filled != ALL)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "%s is missing expected fields", proc_meminfo_path);
+
+        if (mem_available > ctx.mem_total)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "MemAvailable (%" PRIu64 ") cannot be greater than MemTotal (%" PRIu64 ") %m",
+                                       mem_available,
+                                       ctx.mem_total);
+
+        if (swap_free > ctx.swap_total)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "SwapFree (%" PRIu64 ") cannot be greater than SwapTotal (%" PRIu64 ") %m",
+                                       swap_free,
+                                       ctx.swap_total);
+
+        ctx.mem_used = ctx.mem_total - mem_available;
+        ctx.swap_used = ctx.swap_total - swap_free;
+
+        *ret = ctx;
+        return 0;
+}
+
+int oomd_insert_cgroup_context(Hashmap *old_h, Hashmap *new_h, const char *path) {
+        _cleanup_(oomd_cgroup_context_freep) OomdCGroupContext *curr_ctx = NULL;
+        OomdCGroupContext *old_ctx;
+        int r;
+
+        assert(new_h);
+        assert(path);
+
+        path = empty_to_root(path);
+
+        r = oomd_cgroup_context_acquire(path, &curr_ctx);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to get OomdCGroupContext for %s: %m", path);
+
+        assert_se(streq(path, curr_ctx->path));
+
+        old_ctx = hashmap_get(old_h, path);
+        if (old_ctx) {
+                curr_ctx->last_pgscan = old_ctx->pgscan;
+                curr_ctx->mem_pressure_limit = old_ctx->mem_pressure_limit;
+                curr_ctx->mem_pressure_limit_hit_start = old_ctx->mem_pressure_limit_hit_start;
+                curr_ctx->last_had_mem_reclaim = old_ctx->last_had_mem_reclaim;
+        }
+
+        if (oomd_pgscan_rate(curr_ctx) > 0)
+                curr_ctx->last_had_mem_reclaim = now(CLOCK_MONOTONIC);
+
+        r = hashmap_put(new_h, curr_ctx->path, curr_ctx);
+        if (r < 0)
+                return r;
+
+        TAKE_PTR(curr_ctx);
+        return 0;
+}
+
+void oomd_update_cgroup_contexts_between_hashmaps(Hashmap *old_h, Hashmap *curr_h) {
+        OomdCGroupContext *ctx;
+
+        assert(old_h);
+        assert(curr_h);
+
+        HASHMAP_FOREACH(ctx, curr_h) {
+                OomdCGroupContext *old_ctx;
+
+                old_ctx = hashmap_get(old_h, ctx->path);
+                if (!old_ctx)
+                        continue;
+
+                ctx->last_pgscan = old_ctx->pgscan;
+                ctx->mem_pressure_limit = old_ctx->mem_pressure_limit;
+                ctx->mem_pressure_limit_hit_start = old_ctx->mem_pressure_limit_hit_start;
+                ctx->last_had_mem_reclaim = old_ctx->last_had_mem_reclaim;
+
+                if (oomd_pgscan_rate(ctx) > 0)
+                        ctx->last_had_mem_reclaim = now(CLOCK_MONOTONIC);
+        }
+}
+
+void oomd_dump_swap_cgroup_context(const OomdCGroupContext *ctx, FILE *f, const char *prefix) {
+        assert(ctx);
+        assert(f);
+
+        if (!empty_or_root(ctx->path))
+                fprintf(f,
+                        "%sPath: %s\n"
+                        "%s\tSwap Usage: %s\n",
+                        strempty(prefix), ctx->path,
+                        strempty(prefix), FORMAT_BYTES(ctx->swap_usage));
+        else
+                fprintf(f,
+                        "%sPath: %s\n"
+                        "%s\tSwap Usage: (see System Context)\n",
+                        strempty(prefix), ctx->path,
+                        strempty(prefix));
+}
+
+void oomd_dump_memory_pressure_cgroup_context(const OomdCGroupContext *ctx, FILE *f, const char *prefix) {
+        assert(ctx);
+        assert(f);
+
+        fprintf(f,
+                "%sPath: %s\n"
+                "%s\tMemory Pressure Limit: %lu.%02lu%%\n"
+                "%s\tPressure: Avg10: %lu.%02lu Avg60: %lu.%02lu Avg300: %lu.%02lu Total: %s\n"
+                "%s\tCurrent Memory Usage: %s\n",
+                strempty(prefix), ctx->path,
+                strempty(prefix), LOADAVG_INT_SIDE(ctx->mem_pressure_limit), LOADAVG_DECIMAL_SIDE(ctx->mem_pressure_limit),
+                strempty(prefix),
+                LOADAVG_INT_SIDE(ctx->memory_pressure.avg10), LOADAVG_DECIMAL_SIDE(ctx->memory_pressure.avg10),
+                LOADAVG_INT_SIDE(ctx->memory_pressure.avg60), LOADAVG_DECIMAL_SIDE(ctx->memory_pressure.avg60),
+                LOADAVG_INT_SIDE(ctx->memory_pressure.avg300), LOADAVG_DECIMAL_SIDE(ctx->memory_pressure.avg300),
+                FORMAT_TIMESPAN(ctx->memory_pressure.total, USEC_PER_SEC),
+                strempty(prefix), FORMAT_BYTES(ctx->current_memory_usage));
+
+        if (!empty_or_root(ctx->path))
+                fprintf(f,
+                        "%s\tMemory Min: %s\n"
+                        "%s\tMemory Low: %s\n"
+                        "%s\tPgscan: %" PRIu64 "\n"
+                        "%s\tLast Pgscan: %" PRIu64 "\n",
+                        strempty(prefix), FORMAT_BYTES_CGROUP_PROTECTION(ctx->memory_min),
+                        strempty(prefix), FORMAT_BYTES_CGROUP_PROTECTION(ctx->memory_low),
+                        strempty(prefix), ctx->pgscan,
+                        strempty(prefix), ctx->last_pgscan);
+}
+
+void oomd_dump_system_context(const OomdSystemContext *ctx, FILE *f, const char *prefix) {
+        assert(ctx);
+        assert(f);
+
+        fprintf(f,
+                "%sMemory: Used: %s Total: %s\n"
+                "%sSwap: Used: %s Total: %s\n",
+                strempty(prefix),
+                FORMAT_BYTES(ctx->mem_used),
+                FORMAT_BYTES(ctx->mem_total),
+                strempty(prefix),
+                FORMAT_BYTES(ctx->swap_used),
+                FORMAT_BYTES(ctx->swap_total));
+}