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| author | Anita Zhang <the.anitazha@gmail.com> | 2022-01-19 22:26:01 +0100 |
|---|---|---|
| committer | Anita Zhang <the.anitazha@gmail.com> | 2022-01-20 23:15:13 +0100 |
| commit | 914d4e99f43761f1ce77b520850cf096aa5196cd (patch) | |
| tree | 717b1ac211a5f0edfdc99935aa29728fecc0602f /src/oom | |
| parent | oomd: fix race with path unavailability when killing cgroups (diff) | |
| download | systemd-914d4e99f43761f1ce77b520850cf096aa5196cd.tar.xz systemd-914d4e99f43761f1ce77b520850cf096aa5196cd.zip | |
oomd: handle situations when no cgroups are killed
Currently if systemd-oomd doesn't kill anything in a selected cgroup, it
selects a new candidate immediately. But if a selected cgroup wasn't killed,
it is likely due to it disappearing or getting cleaned up between the time
it was selected as a candidate and getting sent SIGKILL(s). We should handle
it as though systemd-oomd did perform a kill so that it will check
swap/pressure again before it tries to select a new candidate.
Diffstat (limited to 'src/oom')
| -rw-r--r-- | src/oom/oomd-manager.c | 10 | ||||
| -rw-r--r-- | src/oom/oomd-util.c | 11 |
2 files changed, 12 insertions, 9 deletions
diff --git a/src/oom/oomd-manager.c b/src/oom/oomd-manager.c index 9f4f083ab9..b0a81474cc 100644 --- a/src/oom/oomd-manager.c +++ b/src/oom/oomd-manager.c @@ -410,7 +410,7 @@ static int monitor_swap_contexts_handler(sd_event_source *s, uint64_t usec, void if (r < 0) log_notice_errno(r, "Failed to kill any cgroup(s) based on swap: %m"); else { - if (selected) + if (selected && r > 0) log_notice("Killed %s due to memory used (%"PRIu64") / total (%"PRIu64") and " "swap used (%"PRIu64") / total (%"PRIu64") being more than " PERMYRIAD_AS_PERCENT_FORMAT_STR, @@ -518,9 +518,13 @@ static int monitor_memory_pressure_contexts_handler(sd_event_source *s, uint64_t if (r < 0) log_notice_errno(r, "Failed to kill any cgroup(s) under %s based on pressure: %m", t->path); else { - /* Don't act on all the high pressure cgroups at once; return as soon as we kill one */ + /* Don't act on all the high pressure cgroups at once; return as soon as we kill one. + * If r == 0 then it means there were not eligible candidates, the candidate cgroup + * disappeared, or the candidate cgroup has no processes by the time we tried to kill + * it. In either case, go through the event loop again and select a new candidate if + * pressure is still high. */ m->mem_pressure_post_action_delay_start = usec_now; - if (selected) + if (selected && r > 0) log_notice("Killed %s due to memory pressure for %s being %lu.%02lu%% > %lu.%02lu%%" " for > %s with reclaim activity", selected, t->path, diff --git a/src/oom/oomd-util.c b/src/oom/oomd-util.c index b54bf483d6..cef7519a74 100644 --- a/src/oom/oomd-util.c +++ b/src/oom/oomd-util.c @@ -206,6 +206,9 @@ int oomd_cgroup_kill(const char *path, bool recurse, bool dry_run) { 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"); @@ -231,8 +234,6 @@ int oomd_kill_by_pgscan_rate(Hashmap *h, const char *prefix, bool dry_run, char continue; r = oomd_cgroup_kill(sorted[i]->path, true, dry_run); - if (r == 0) - continue; /* We didn't find anything to kill */ if (r == -ENOMEM) return r; /* Treat oom as a hard error */ if (r < 0) { @@ -245,7 +246,7 @@ int oomd_kill_by_pgscan_rate(Hashmap *h, const char *prefix, bool dry_run, char if (!selected) return -ENOMEM; *ret_selected = selected; - return 1; + return r; } return ret; @@ -271,8 +272,6 @@ int oomd_kill_by_swap_usage(Hashmap *h, uint64_t threshold_usage, bool dry_run, continue; r = oomd_cgroup_kill(sorted[i]->path, true, dry_run); - if (r == 0) - continue; /* We didn't find anything to kill */ if (r == -ENOMEM) return r; /* Treat oom as a hard error */ if (r < 0) { @@ -285,7 +284,7 @@ int oomd_kill_by_swap_usage(Hashmap *h, uint64_t threshold_usage, bool dry_run, if (!selected) return -ENOMEM; *ret_selected = selected; - return 1; + return r; } return ret; |