small changes

Author: vpuri3

src/common.jl

@@ -42,6 +42,11 @@ function SciMLBase.init(
     kwargs...,
 )
     @unpack A, b, u0, p = prob
+
+    if u0 == nothing
+        u0 = zero(b)
+    end
+
     if alg isa LUFactorization
         fact = lu_instance(A)
         Tfact = typeof(fact)
@@ -52,13 +57,11 @@ function SciMLBase.init(
     Pr = LinearAlgebra.I
     Pl = LinearAlgebra.I
 
+#   @show (A, b, u0, p) |> typeof
+
     A = alias_A ? A : copy(A)
     b = alias_b ? b : copy(b)
 
-    if u0 == nothing
-        u0 = zero(b)
-    end
-
     cache = LinearCache{
         typeof(A),
         typeof(b),

src/krylov.jl

@@ -1,10 +1,14 @@
+## Krylov.jl
+
+# place Krylov.CGsolver in LinearCache.cacheval, and resule
+
 struct KrylovJL{A,K} <: SciMLLinearSolveAlgorithm
     solver::Function
     args::A
     kwargs::K
 end
 
-function KrylovJL(args...; solver = gmres, kwargs...)
+function KrylovJL(args...; solver = Krylov.gmres, kwargs...)
     return KrylovJL(solver, args, kwargs)
 end
 
@@ -15,3 +19,14 @@ function SciMLBase.solve(cache::LinearCache, alg::KrylovJL,args...;kwargs...)
     retcode = stats.solved ? :Success : :Failure
     return u #SciMLBase.build_solution(prob, alg, x, resid; retcode = retcode)
 end
+
+## IterativeSolvers.jl
+
+struct IterativeSolversJL{A,K} <: SciMLLinearSolveAlgorithm
+    solver::Function
+    args::A
+    kwargs::K
+end
+
+## KrylovKit.jl
+