From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH v5 2/3] syscalls/msgstress03: fix fork failure on small memory systems
Date: Fri, 20 Aug 2021 12:00:27 +0200 [thread overview]
Message-ID: <20210820100028.97487-3-krzysztof.kozlowski@canonical.com> (raw)
In-Reply-To: <20210820100028.97487-1-krzysztof.kozlowski@canonical.com>
Running syscalls/msgstress03 on a system with less than ~4 GB of RAM fails:
msgstress03 1 TFAIL : msgstress03.c:155: Fork failed (may be OK if under stress)
In dmesg:
LTP: starting msgstress03
cgroup: fork rejected by pids controller in /user.slice/user-1000.slice/session-1.scope
The reason is cgroups pid limit set by systemd user.slice. The limit is
set for login session, also for root user. For example on 2 GB RAM
machine it is set as:
/sys/fs/cgroup/pids/user.slice/user-0.slice/pids.max:5207
Read the maximum number of pids and adjust the test limit. For 2 GB RAM
machine with systemd this will result in:
msgstress03 0 TINFO : Found limit of processes 5056 (from /sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max)
msgstress03 0 TINFO : Requested number of processes higher than user session limit (10000 > 4556), setting to 4556
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
testcases/kernel/syscalls/ipc/msgstress/msgstress03.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/testcases/kernel/syscalls/ipc/msgstress/msgstress03.c b/testcases/kernel/syscalls/ipc/msgstress/msgstress03.c
index 294b401b1b38..3cb70ab18a80 100644
--- a/testcases/kernel/syscalls/ipc/msgstress/msgstress03.c
+++ b/testcases/kernel/syscalls/ipc/msgstress/msgstress03.c
@@ -78,7 +78,7 @@ static void usage(void)
int main(int argc, char **argv)
{
- int i, j, ok, pid;
+ int i, j, ok, pid, free_pids;
int count, status;
struct sigaction act;
@@ -109,6 +109,14 @@ int main(int argc, char **argv)
}
}
+ free_pids = tst_get_free_pids(cleanup);
+ if (nprocs >= free_pids) {
+ tst_resm(TINFO,
+ "Requested number of processes higher than limit (%d > %d), "
+ "setting to %d", nprocs, free_pids, free_pids);
+ nprocs = free_pids;
+ }
+
srand(getpid());
tid = -1;
--
2.30.2
next prev parent reply other threads:[~2021-08-20 10:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 10:00 [LTP] [PATCH v5 0/3] syscalls/msgstress: fixes for small systems Krzysztof Kozlowski
2021-08-20 10:00 ` [LTP] [PATCH v5 1/3] lib/tst_pid: simplify error handling by callers of tst_get_free_pids() Krzysztof Kozlowski
2021-08-20 10:00 ` Krzysztof Kozlowski [this message]
2021-08-20 10:00 ` [LTP] [PATCH v5 3/3] syscalls/msgstress: tune limit of processes for small machines Krzysztof Kozlowski
2021-08-20 13:34 ` Cyril Hrubis
2021-08-26 9:50 ` Krzysztof Kozlowski
2021-08-20 13:34 ` [LTP] [PATCH v5 0/3] syscalls/msgstress: fixes for small systems Cyril Hrubis
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210820100028.97487-3-krzysztof.kozlowski@canonical.com \
--to=krzysztof.kozlowski@canonical.com \
--cc=ltp@lists.linux.it \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.