From 6c8de1e221461ae2d8920486ad0b3b79c27488c0 Mon Sep 17 00:00:00 2001 From: Nathan Hjelm Date: Fri, 21 Nov 2025 09:00:32 -0700 Subject: [PATCH] btl/uct: update btl default limits When a module is created for a UCT transport we take the min of the transport limits and whatever the default is in the module. This is done to support user provided limits. The issue is the limits are too low and they end up overriding the transport limits when the user hasn't specified anything. To fix this issue this commit changes the put/get limit to SIZE_T_MAX and the send limits to 256kiB. This issue was detected with a large message benchmark where it was discovered that ob1 was not performing put or get operations over 4MiB even though the hardware supported larger sizes. Signed-off-by: Nathan Hjelm --- opal/mca/btl/uct/btl_uct_module.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/opal/mca/btl/uct/btl_uct_module.c b/opal/mca/btl/uct/btl_uct_module.c index 9914c5e8f99..3ae2172c2df 100644 --- a/opal/mca/btl/uct/btl_uct_module.c +++ b/opal/mca/btl/uct/btl_uct_module.c @@ -374,18 +374,20 @@ mca_btl_uct_module_t mca_btl_uct_module_template = { | MCA_BTL_ATOMIC_SUPPORTS_CSWAP | MCA_BTL_ATOMIC_SUPPORTS_SWAP | MCA_BTL_ATOMIC_SUPPORTS_32BIT, - /* set the default limits on put and get */ - .btl_put_limit = 1 << 23, + /* set the default limits on put and get. these can be overridden by what is + * supported by the transport or what the user specified. */ + .btl_put_limit = SIZE_T_MAX, .btl_put_alignment = 0, - .btl_get_limit = 1 << 23, + .btl_get_limit = SIZE_T_MAX, .btl_get_alignment = 0, - .btl_rndv_eager_limit = 8192, + .btl_rndv_eager_limit = 131072, .btl_rdma_pipeline_frag_size = 4 * 1024 * 1024, - .btl_rdma_pipeline_send_length = 8192, - .btl_eager_limit = 8192, - .btl_max_send_size = 65536, - /* for now we want this component to lose to btl/ugni and btl/vader */ + .btl_rdma_pipeline_send_length = 131072, + .btl_eager_limit = 131072, + .btl_max_send_size = 131072, + + /* for now we want this component to lose to btl/vader */ .btl_exclusivity = MCA_BTL_EXCLUSIVITY_HIGH - 1, }};