LU-10157 lnet: restore an maximal fragments count

Lowering a number of fragments blocks a connection from older clients
who want to use 256 fragments to transfer. Let's restore this number
to the original value.

Lustre-change: https://review.whamcloud.com/37385
Lustre-commit: 4072d863c240fa5466f0f616f7e9b1cfcdf0aa0e

Fixes: 272e49c ("LU-10157 lnet: make LNET_MAX_IOV dependent on page size")
Cray-bug-id: LUS-8139
Test-Parameters: trivial testlist=lnet-selftest,sanity-lnet
Signed-off-by: Alexey Lyashkov <c17817@cray.com>
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: I94ac16c1c75efda3e5f3f35ddfc5f39921c15873
Reviewed-on: https://review.whamcloud.com/41277
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Amir Shehata <ashehata@whamcloud.com>
Reviewed-by: Alexey Lyashkov <alexey.lyashkov@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lnet/include/lnet/lib-types.h b/lnet/include/lnet/lib-types.h
index 0902deb..496a1b0 100644 (file)
--- a/lnet/include/lnet/lib-types.h
+++ b/lnet/include/lnet/lib-types.h
@@ -53,7 +53,8 @@
 /* Max payload size */
 #define LNET_MAX_PAYLOAD       LNET_MTU
 
-#define LNET_MAX_IOV           (LNET_MAX_PAYLOAD >> PAGE_SHIFT)
+/** limit on the number of fragments in discontiguous MDs */
+#define LNET_MAX_IOV   256
 
 /*
  * This is the maximum health value.