X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=README.md;fp=README.md;h=7ce0edfeec0ef4203e286a4661eac6f7dd9ddeb1;hp=6fe9c1ef1bb117556a580f188d4cc46b46f364b9;hb=d8d9a3405ce46af6d34d2e80e260ad50f3d211a0;hpb=0b9c513b2513c37e3ed0a5ee047b8d40eef482ab

diff --git a/README.md b/README.md
index 6fe9c1e..7ce0edf 100644
--- a/README.md
+++ b/README.md
@@ -159,7 +159,11 @@ This is the preferred version of the library, in terms of
 grace-period detection speed, read-side speed and flexibility.
 Dynamically detects kernel support for `sys_membarrier()`. Falls back
 on `urcu-mb` scheme if support is not present, which has slower
-read-side.
+read-side. Use the --disable-sys-membarrier-fallback configure option
+to disable the fall back, thus requiring `sys_membarrier()` to be
+available. This gives a small speedup when `sys_membarrier()` is
+supported by the kernel, and aborts in the library constructor if not
+supported.
 
 
 ### Usage of `liburcu-qsbr`