One doc tagged with "syncthreads"

The warp-level tools covered so far — divergence handling, independent thread scheduling, the shuffle and vote intrinsics — all operate within a single warp of 32 threads. Most kernels that use shared memory need something coarser: a guarantee that every thread in the whole block, potentially many warps, has reached a point and that everything they wrote before that point is visible to everything they read after it. That guarantee is syncthreads(), and getting its rules exactly right is what stands between a working tiled kernel and one that hangs or reads garbage on some inputs and not others.