path: root/README
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authorJens Axboe <>2019-11-10 22:10:27 -0700
committerJens Axboe <>2019-11-10 22:10:27 -0700
commitd9b3a105090749311de3eb8e5643acf3f20e8ebe (patch)
tree7a75f2d5733c51861f353cc879d5cd077b92c1fa /README
parentd4196c2241e0466569cbe67692d962630386007e (diff)
README: add small blurb on rlimit memlocked (ulimit -l)
Signed-off-by: Jens Axboe <>
Diffstat (limited to 'README')
1 files changed, 15 insertions, 1 deletions
diff --git a/README b/README
index 6471964..98ca767 100644
--- a/README
+++ b/README
@@ -15,4 +15,18 @@ and development for both kernel and userspace. The list is archived here:
-Jens Axboe 2019-08-05
+ulimit settings
+io_uring accounts memory it needs under the rlimit memlocked option, which
+can be quite low on some setups (64K). The default is usually enough for
+most use cases, but bigger rings or things like registered buffers deplete
+it quickly. root isn't under this restriction, but regular users are. Going
+into detail on how to bump the limit on various systems is beyond the scope
+of this little blurb, but check /etc/security/limits.conf for user specific
+settings, or /etc/systemd/user.conf and /etc/systemd/system.conf for systemd
+Jens Axboe 2019-11-10