From 135400276c2b8262d2946bfa1369ae46055d664b Mon Sep 17 00:00:00 2001 From: Dan Streetman Date: Fri, 14 May 2021 08:08:33 -0400 Subject: [PATCH] oom: log one-time warning if kernel doesn't provide memory.swap.current The kernel can be compiled without support for any memory.swap.* files, or it can be disabled at boot time with the 'swapaccount=0' boot parameter, so if the file doesn't exist log warning indicating the kernel doesn't support the file and the user may need to try using the 'swapaccount=1' boot param. Note that the actual error from the call to fopen() is ENOENT, but that is translated into ENODATA in cg_get_attribute_as_uint64() --- src/oom/oomd-util.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/oom/oomd-util.c b/src/oom/oomd-util.c index 5bf81479c9f..0550ac6c74e 100644 --- a/src/oom/oomd-util.c +++ b/src/oom/oomd-util.c @@ -333,7 +333,11 @@ int oomd_cgroup_context_acquire(const char *path, OomdCGroupContext **ret) { 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 < 0) + 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); -- 2.47.3