[PATCH v1 1/2] SUNRPC: Add trace event when alloc_pages_bulk() makes no progress
From: Chuck Lever <chuck.lever@oracle.com>
Date: 2021-09-22 17:02:08
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest, tracing · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
This is an operational low memory situation that needs to be flagged. The new tracepoint records a timestamp and the nfsd thread that failed to allocate pages. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- include/trace/events/sunrpc.h | 18 ++++++++++++++++++ net/sunrpc/svc_xprt.c | 1 + 2 files changed, 19 insertions(+)
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 2d04eb96d418..fb016308c185 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h@@ -1859,6 +1859,24 @@ TRACE_EVENT(svc_wake_up, TP_printk("pid=%d", __entry->pid) ); +TRACE_EVENT(svc_alloc_arg_err, + TP_PROTO( + unsigned int pages + ), + + TP_ARGS(pages), + + TP_STRUCT__entry( + __field(unsigned int, pages) + ), + + TP_fast_assign( + __entry->pages = pages; + ), + + TP_printk("pages=%u", __entry->pages) +); + TRACE_EVENT(svc_handle_xprt, TP_PROTO(struct svc_xprt *xprt, int len),
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 6316bd2b8f37..1e99ba1b9d72 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c@@ -687,6 +687,7 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) set_current_state(TASK_RUNNING); return -EINTR; } + trace_svc_alloc_arg_err(pages); schedule_timeout(msecs_to_jiffies(500)); } rqstp->rq_page_end = &rqstp->rq_pages[pages];