diff --git a/docs/html/footnode.html b/docs/html/footnode.html index b94373fd..086fb082 100644 --- a/docs/html/footnode.html +++ b/docs/html/footnode.html @@ -1,6 +1,6 @@ - diff --git a/docs/html/node1.html b/docs/html/node1.html index d37d1c64..aa41f85b 100644 --- a/docs/html/node1.html +++ b/docs/html/node1.html @@ -1,6 +1,6 @@ - \begin{displaymath}dot \leftarrow x^H y\end{displaymath}

- 

 psb_gedot(x, y, desc_a, info)
@@ -124,10 +123,10 @@ Data types
 

 

 
$dot$, $x$, 
 
x

 
the local portion of global dense matrix
 $x$.
 

@@ -178,7 +177,7 @@ Intent: in.
 Specified as:  a rank one or two array or an object of type vdatapsb_T_vect_type 
 containing numbers of type specified in
 Table 2. The rank of $x$ must be the same of 2. The rank of $y$ must be the same of $x$. 
 

@@ -218,7 +217,6 @@ Type: required
 Intent: in.
 

 Specified as: an object of type descdatapsb_desc_type.
-
 

 
 
On Return

@@ -226,7 +224,7 @@ Specified as: an object of type descdatapsb_desc_type.
 
 
Function value

 
is the dot product of subvectors $x$ and out.
 An integer value; 0 means no error has been detected. 
 

 
-
 

 

 
diff --git a/docs/html/node54.html b/docs/html/node54.html
index fbf178e4..53c60c62 100644
--- a/docs/html/node54.html
+++ b/docs/html/node54.html
@@ -1,6 +1,6 @@
 
 
-
diff --git a/docs/html/node56.html b/docs/html/node56.html
index cddeff04..3c6b12b0 100644
--- a/docs/html/node56.html
+++ b/docs/html/node56.html
@@ -1,6 +1,6 @@
 
 
-
 
 \begin{displaymath}res(i) \leftarrow \max_k \vert x(k,i)\vert \end{displaymath}
 
@@ -92,11 +92,11 @@ Data types
 

 
@@ -135,7 +135,7 @@ Data types
x
the local portion of global dense matrix
 $x$. 
 

@@ -165,7 +165,7 @@ Specified as: an object of type descdatapsb_desc_type.
 
res
is the infinity norm of the columns of $x$.
 

diff --git a/docs/html/node57.html b/docs/html/node57.html
index 4665c65e..53f40a07 100644
--- a/docs/html/node57.html
+++ b/docs/html/node57.html
@@ -1,6 +1,6 @@
 
 
-
 
 \begin{displaymath}res(i) \leftarrow \max_k \vert x(k,i)\vert \end{displaymath}
 
 

 

 This function computes the 1-norm of a vector $x$.
 

 If $x$ is a real vector 
 it computes 1-norm as:
@@ -102,7 +102,7 @@ res(i) \leftarrow  \|x_i\|
 

 

 else if $x$ is a complex vector then it computes 1-norm  as:
 

@@ -114,7 +114,7 @@ res(i) \leftarrow \|re(x)\|_1 + \|im(x)\|_1
  -->
 
 \begin{displaymath}res(i) \leftarrow \Vert re(x)\Vert _1 + \Vert im(x)\Vert _1\end{displaymath}
 
@@ -136,11 +136,11 @@ Data types
 

 

 
$res$
 $x$
 Subroutine
 
 
 
 

@@ -179,10 +179,9 @@ Data types
x
the local portion of global dense matrix
 $x$. 
-
 

 Scope: local 
 

@@ -212,7 +211,7 @@ Specified as: an object of type descdatapsb_desc_type.
 
res
contains the 1-norm of (the columns of) $x$.
 

diff --git a/docs/html/node59.html b/docs/html/node59.html
index a22b3734..3c747c6b 100644
--- a/docs/html/node59.html
+++ b/docs/html/node59.html
@@ -1,6 +1,6 @@
 
 
-
 
 \begin{displaymath}res(i) \leftarrow \Vert x(:,i)\Vert _2 \end{displaymath}
 
@@ -92,11 +92,11 @@ Data types
 

 

 
$res$
 $x$
 Subroutine
 
 
 
 

@@ -135,10 +135,9 @@ Data types
x
the local portion of global dense matrix
 $x$. 
-
 

 Scope: local 
 

@@ -168,7 +167,7 @@ Specified as: an object of type descdatapsb_desc_type.
 
res
contains the 1-norm of (the columns of) $x$.
 

diff --git a/docs/html/node61.html b/docs/html/node61.html
index 7a7d040b..b9707887 100644
--- a/docs/html/node61.html
+++ b/docs/html/node61.html
@@ -1,6 +1,6 @@
 
 
-
 
 \begin{displaymath}nrm1 \leftarrow \Vert A\Vert _1 \end{displaymath}
 
diff --git a/docs/html/node62.html b/docs/html/node62.html
index bb9f341a..cf8550f7 100644
--- a/docs/html/node62.html
+++ b/docs/html/node62.html
@@ -1,6 +1,6 @@
 
 
-
 
 \begin{displaymath}nrmi \leftarrow \Vert A\Vert _\infty \end{displaymath}
 
diff --git a/docs/html/node63.html b/docs/html/node63.html
index ecc265dd..1c7c14b5 100644
--- a/docs/html/node63.html
+++ b/docs/html/node63.html
@@ -1,6 +1,6 @@
 
 
-
 
 \begin{displaymath}loc\_x_i \leftarrow scatter(glob\_x) \end{displaymath}
 
@@ -99,7 +99,7 @@ process $i$.
 
$scatter$
is the scatter function.
@@ -146,7 +146,7 @@ Data types
 

 

 \begin{lstlisting}
 call psb_scatter(glob_x, loc_x, desc_a, info, root, mold)
diff --git a/docs/html/node7.html b/docs/html/node7.html
index 5e6419ac..88b2e9b2 100644
--- a/docs/html/node7.html
+++ b/docs/html/node7.html
@@ -1,6 +1,6 @@
 <!DOCTYPE HTML PUBLIC 
 
-
 
 
diff --git a/docs/psblas-3.5.pdf b/docs/psblas-3.5.pdf
index 03645c0d..ac39e96e 100644
--- a/docs/psblas-3.5.pdf
+++ b/docs/psblas-3.5.pdf
@@ -21199,7 +21199,7 @@ endstream
 endobj
 1708 0 obj
 <<
-/Length 1822      
+/Length 2936      
 >>
 stream
 0 g 0 G
@@ -21208,7 +21208,7 @@ BT
 /F16 11.9552 Tf 150.705 706.129 Td [(descr)-375(|)-375(Prin)31(ts)-375(a)-375(description)-375(of)-375(curren)31(t)-375(preconditioner)]TJ
 0 g 0 G
 0 g 0 G
-/F30 9.9626 Tf 0 -18.389 Td [(call)-525(prec%descr\050\051)]TJ 0 -11.956 Td [(call)-525(prec%descr\050iout\051)]TJ
+/F30 9.9626 Tf 0 -18.389 Td [(call)-525(prec%descr\050\051)]TJ 0 -11.956 Td [(call)-525(prec%descr\050iout,)-525(root\051)]TJ
 0 g 0 G
 /F27 9.9626 Tf 0 -21.917 Td [(T)32(yp)-32(e:)]TJ
 0 g 0 G
@@ -21241,9 +21241,13 @@ BT
 0 g 0 G
 /F27 9.9626 Tf -287.509 -19.925 Td [(iout)]TJ
 0 g 0 G
-/F8 9.9626 Tf 24.713 0 Td [(output)-333(unit.)-444(Scop)-28(e:)]TJ/F27 9.9626 Tf 89.94 0 Td [(lo)-32(cal)]TJ/F8 9.9626 Tf -89.747 -11.955 Td [(T)28(yp)-28(e:)]TJ/F27 9.9626 Tf 29.612 0 Td [(optiona)]TJ/F8 9.9626 Tf -29.612 -11.955 Td [(In)28(ten)28(t:)]TJ/F27 9.9626 Tf 33.486 0 Td [(in)]TJ/F8 9.9626 Tf 9.548 0 Td [(.)]TJ -43.034 -11.955 Td [(Sp)-28(eci\014ed)-333(as:)-445(an)-333(in)28(teger)-333(n)27(um)28(b)-28(er.)]TJ
+/F8 9.9626 Tf 24.713 0 Td [(output)-333(unit.)-444(Scop)-28(e:)]TJ/F27 9.9626 Tf 89.94 0 Td [(lo)-32(cal)]TJ/F8 9.9626 Tf -89.747 -11.955 Td [(T)28(yp)-28(e:)]TJ/F27 9.9626 Tf 29.612 0 Td [(optional)]TJ/F8 9.9626 Tf -29.612 -11.955 Td [(In)28(ten)28(t:)]TJ/F27 9.9626 Tf 33.486 0 Td [(in)]TJ/F8 9.9626 Tf 9.548 0 Td [(.)]TJ -43.034 -11.955 Td [(Sp)-28(eci\014ed)-333(as:)-445(an)-333(in)28(teger)-333(n)27(um)28(b)-28(er.)-444(Default:)-444(default)-334(outpu)1(t)-334(unit.)]TJ
 0 g 0 G
- 139.477 -431.922 Td [(132)]TJ
+/F27 9.9626 Tf -24.906 -19.926 Td [(ro)-32(ot)]TJ
+0 g 0 G
+/F8 9.9626 Tf 25.93 0 Td [(Pro)-28(cess)-333(from)-334(whic)28(h)-333(to)-333(prin)28(t)-334(Scop)-28(e:)]TJ/F27 9.9626 Tf 157.244 0 Td [(lo)-32(cal)]TJ/F8 9.9626 Tf -158.268 -11.955 Td [(T)28(yp)-28(e:)]TJ/F27 9.9626 Tf 29.612 0 Td [(optional)]TJ/F8 9.9626 Tf -29.612 -11.955 Td [(In)28(ten)28(t:)]TJ/F27 9.9626 Tf 33.486 0 Td [(in)]TJ/F8 9.9626 Tf 9.547 0 Td [(.)]TJ -43.033 -11.955 Td [(Sp)-28(eci\014ed)-478(as:)-733(an)-478(in)28(teger)-478(n)28(um)27(b)-27(er)-478(b)-28(et)28(w)28(een)-478(0)-478(and)]TJ/F11 9.9626 Tf 220.073 0 Td [(np)]TJ/F14 9.9626 Tf 14.166 0 Td [(\000)]TJ/F8 9.9626 Tf 10.922 0 Td [(1,)-514(in)-478(whic)28(h)-478(case)]TJ -245.161 -11.955 Td [(the)-410(sp)-28(eci\014ed)-410(pro)-28(cess)-410(will)-411(pri)1(n)27(t)-410(the)-410(description,)-429(or)]TJ/F14 9.9626 Tf 225 0 Td [(\000)]TJ/F8 9.9626 Tf 7.749 0 Td [(1,)-429(in)-411(whic)28(h)-410(case)-410(all)]TJ -232.749 -11.955 Td [(pro)-28(cesses)-333(will)-334(prin)28(t.)-444(Default:)-445(0.)]TJ
+0 g 0 G
+ 139.477 -352.221 Td [(132)]TJ
 0 g 0 G
 ET
 
@@ -21810,7 +21814,7 @@ endobj
 /Type /ObjStm
 /N 100
 /First 969
-/Length 10842     
+/Length 10868     
 >>
 stream
 1652 0 1650 139 1654 283 493 342 1655 400 1656 459 1651 518 1659 624 1661 742 497 800
@@ -21818,11 +21822,11 @@ stream
 1672 1702 1674 1820 505 1878 1675 1935 1676 1993 1671 2051 1679 2157 1681 2275 509 2334 1678 2392
 1685 2498 1682 2646 1683 2793 1687 2943 513 3001 1688 3058 1684 3116 1694 3273 1689 3439 1690 3583
 1691 3728 1692 3875 1696 4022 517 4081 1693 4139 1702 4245 1697 4411 1698 4557 1699 4700 1700 4847
-1704 4991 521 5049 1701 5106 1707 5212 1705 5351 1709 5497 525 5556 1706 5614 1711 5720 1713 5838
-529 5896 1710 5953 1718 6059 1715 6207 1716 6353 1720 6500 533 6559 1717 6617 1722 6723 1724 6841
-537 6899 1721 6956 1729 7049 1725 7197 1726 7346 1731 7490 541 7549 1732 7607 1733 7666 1734 7725
-1735 7784 1728 7842 1741 8039 1727 8205 1737 8352 1738 8495 1739 8639 1743 8786 1740 8844 1746 8963
-1744 9102 1748 9246 1745 9305 1750 9411 1752 9529 1753 9587 729 9645 1754 9702 780 9759 779 9816
+1704 4991 521 5049 1701 5106 1707 5212 1705 5351 1709 5497 525 5556 1706 5614 1711 5746 1713 5864
+529 5922 1710 5979 1718 6085 1715 6233 1716 6379 1720 6526 533 6585 1717 6643 1722 6749 1724 6867
+537 6925 1721 6982 1729 7075 1725 7223 1726 7372 1731 7516 541 7575 1732 7633 1733 7692 1734 7751
+1735 7810 1728 7868 1741 8065 1727 8231 1737 8378 1738 8521 1739 8665 1743 8812 1740 8870 1746 8989
+1744 9128 1748 9272 1745 9331 1750 9437 1752 9555 1753 9613 729 9671 1754 9728 780 9785 779 9842
 % 1652 0 obj
 <<
 /Type /Page
@@ -22155,7 +22159,7 @@ stream
 >>
 % 1706 0 obj
 <<
-/Font << /F16 550 0 R /F30 759 0 R /F27 552 0 R /F8 553 0 R >>
+/Font << /F16 550 0 R /F30 759 0 R /F27 552 0 R /F8 553 0 R /F11 745 0 R /F14 762 0 R >>
 /ProcSet [ /PDF /Text ]
 >>
 % 1711 0 obj
@@ -26962,9 +26966,9 @@ endstream
 endobj
 1936 0 obj
 <<
- /Title (Parallel Sparse BLAS V. 3.5.0) /Subject (Parallel Sparse Basic Linear Algebra Subroutines) /Keywords (Computer Science Linear Algebra Fluid Dynamics Parallel Linux MPI PSBLAS Iterative Solvers Preconditioners) /Creator (pdfLaTeX) /Producer ($Id: userguide.tex 9755 2016-05-25 10:15:57Z sfilippo $) /Author()/Title()/Subject()/Creator(LaTeX with hyperref package)/Producer(pdfTeX-1.40.17)/Keywords()
-/CreationDate (D:20170407152605+01'00')
-/ModDate (D:20170407152605+01'00')
+ /Title (Parallel Sparse BLAS V. 3.5.0) /Subject (Parallel Sparse Basic Linear Algebra Subroutines) /Keywords (Computer Science Linear Algebra Fluid Dynamics Parallel Linux MPI PSBLAS Iterative Solvers Preconditioners) /Creator (pdfLaTeX) /Producer ($Id: userguide.tex 10516 2017-04-07 15:20:39Z sfilippo $) /Author()/Title()/Subject()/Creator(LaTeX with hyperref package)/Producer(pdfTeX-1.40.17)/Keywords()
+/CreationDate (D:20170408102502+01'00')
+/ModDate (D:20170408102502+01'00')
 /Trapped /False
 /PTEX.Fullbanner (This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016) kpathsea version 6.2.2)
 >>
@@ -27236,7 +27240,7 @@ endobj
 /W [1 3 1]
 /Root 1935 0 R
 /Info 1936 0 R
-/ID [ ]
+/ID [<32C173B60CAAA4156F1063D2894312EB> <32C173B60CAAA4156F1063D2894312EB>]
 /Length 9690      
 >>
 stream
@@ -27272,12 +27276,12 @@ w
 gSUV]X
 Y[\\c^
 O_ab4I	
-^
s]7899 !"#$%&'()*+,-./0123456?:b;=>E@,ACDKFGIJQL}MOPURS^W\VKXZ[^c]2_abyyy.*yyy
4cyy<yy
-yyyy
Kcyyyyy[yyy_yyikyyy y$ym8y!y#y&y'y(y)y,y%	y*y.y/y0y1y4y-y2y6y9y5y7y=y: y;`y?y@yCy>:yAyGyD!yEyIyJySyQyHʴyKyMyNyOyP=yTyUyVyXyR\yWyZy\yY
Ey[y]
y^y_yaa>	
_
- !"#$
k%
&'8i(y)*+f,C-b,.(/î0t1+2H345`6bc     "(")"*"+","-"."/"0"1"2"3"4"5"6"7"8"9":";"<"=">"?"@"A"B"C"D"E"F"G"H"I"J"K"L"M"N"O"P"Q"R"S"T"U"V"W"X"Y"Z"["\"]"^"_"`"a"b"c``````````	`
-```
``````````````````` `!`"`#`$`%`&`'`(`)`*`+`,`-`.`/E
+^
s]7899 !"#$%&'()*+,-./0123456?:b;=>E@,ACDKFGIJQL}MOPURS^W\VKXZ[^c]2_abyyy.*yyy
8yy<yy
+yyyy
Kcyyyyy[yyy_yyikyyy y$ym8y!y#y&y'y(y)y,y%	y*y.y/y0y1y4y-y2y6y9y5y7y=y:zy;`y?y@yCy>yAyGyD{yEyIyJySyQyHyKyMyNyOyP=yTyUyVyXyRyWyZy\yY
y[y]
y^y_yaaB	
c
+ !"#$
o%
?&V'<(~)*u+,G-f./"01/2M434n56bc    | "(")"*"+","-"."/"0"1"2"3"4"5"6"7"8"9":";"<"=">"?"@"A"B"C"D"E"F"G"H"I"J"K"L"M"N"O"P"Q"R"S"T"U"V"W"X"Y"Z"["\"]"^"_"`"a"b"c`.`````````	`
+```
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 endstream
 endobj
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 %%EOF
diff --git a/docs/src/Makefile b/docs/src/Makefile
index 1a725cae..54707fbc 100644
--- a/docs/src/Makefile
+++ b/docs/src/Makefile
@@ -138,7 +138,7 @@ PDF      = $(join $(BASEFILE),.pdf)
 PS       = $(join $(BASEFILE),.ps)
 GXS      = $(join $(BASEFILE),.gxs)
 GLX      = $(join $(BASEFILE),.glx)
-TARGETPDF= ../psblas-3.4.pdf
+TARGETPDF= ../psblas-3.5.pdf
 BASEHTML = $(patsubst %.tex,%,$(HTMLFILE))
 HTML     = $(join $(HTMLFILE),.html)
 HTMLDIR  = ../html
diff --git a/docs/src/precs.tex b/docs/src/precs.tex
index d8d58221..7d64f8e9 100644
--- a/docs/src/precs.tex
+++ b/docs/src/precs.tex
@@ -200,7 +200,7 @@ An integer value; 0 means no error has been detected.
 
 \begin{verbatim}
 call prec%descr()
-call prec%descr(iout)
+call prec%descr(iout, root)
 \end{verbatim}
 
 \begin{description}
@@ -213,9 +213,16 @@ Intent: {\bf in}.\\
 Specified as: a preconditioner data structure \precdata.
 \item[iout] output unit.
 Scope: {\bf local} \\
-Type: {\bf optiona}\\
+Type: {\bf optional}\\
+Intent: {\bf in}.\\
+Specified as: an integer number. Default: default output unit.
+\item[root] Process from which to print
+Scope: {\bf local} \\
+Type: {\bf optional}\\
 Intent: {\bf in}.\\
-Specified as: an integer number. 
+Specified as: an integer number between 0 and $np-1$, in which case
+the specified process will print the description, or $-1$, in which case
+all processes will print. Default: 0. 
 \end{description}
 
 
diff --git a/prec/psb_c_base_prec_mod.f90 b/prec/psb_c_base_prec_mod.f90
index 25731b81..624b9c7c 100644
--- a/prec/psb_c_base_prec_mod.f90
+++ b/prec/psb_c_base_prec_mod.f90
@@ -60,6 +60,7 @@ module psb_c_base_prec_mod
     generic, public       :: apply     => c_apply, c_apply_v
     generic, public       :: build     => precbld
     generic, public       :: descr     => precdescr
+    procedure, pass(prec) :: desc_prefix => psb_c_base_desc_prefix
     procedure(psb_c_base_precbld), pass(prec), deferred :: precbld    
     procedure(psb_c_base_sizeof), pass(prec), deferred :: sizeof     
     procedure(psb_c_base_precinit), pass(prec), deferred :: precinit   
@@ -156,7 +157,7 @@ module psb_c_base_prec_mod
 
 
   abstract interface 
-    subroutine psb_c_base_precdescr(prec,iout)
+    subroutine psb_c_base_precdescr(prec,iout,root)
       import psb_ipk_, psb_spk_, psb_desc_type, psb_c_vect_type, &
            & psb_c_base_vect_type, psb_cspmat_type, psb_c_base_prec_type,&
            & psb_c_base_sparse_mat
@@ -164,6 +165,7 @@ module psb_c_base_prec_mod
 
       class(psb_c_base_prec_type), intent(in) :: prec
       integer(psb_ipk_), intent(in), optional    :: iout
+      integer(psb_ipk_), intent(in), optional    :: root
 
     end subroutine psb_c_base_precdescr
   end interface
@@ -289,4 +291,27 @@ contains
 
   end function psb_c_base_get_nzeros
 
+  function psb_c_base_desc_prefix(prec) result(res)
+    use psb_base_mod, only : psb_info, psb_root_
+    implicit none 
+    class(psb_c_base_prec_type), intent(in) :: prec
+    character(len=32) :: res 
+    !
+    character(len=32) :: frmtv
+    integer(psb_ipk_) :: ni, ictxt,iam,np
+
+    ictxt = prec%ictxt
+    call psb_info(ictxt,iam,np)
+    
+    res = ''
+    if (iam /= psb_root_) then
+      ni  = floor(log10(1.0*np)) + 1
+      write(frmtv,'(a,i8.8,a)') '(a,i',ni,',a)'
+      write(res,frmtv) 'Process ',iam,': Preconditioner: '
+    else
+      write(res,'(a)') 'Preconditioner: '
+    end if
+
+  end function psb_c_base_desc_prefix
+
 end module psb_c_base_prec_mod
diff --git a/prec/psb_c_bjacprec.f90 b/prec/psb_c_bjacprec.f90
index aac1b3c0..ceb60c61 100644
--- a/prec/psb_c_bjacprec.f90
+++ b/prec/psb_c_bjacprec.f90
@@ -133,17 +133,18 @@ module psb_c_bjacprec
 
 contains
 
-  subroutine psb_c_bjac_precdescr(prec,iout)
+  subroutine psb_c_bjac_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     implicit none 
 
     class(psb_c_bjac_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
-    character(len=20)  :: name='c_bjac_precdescr'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=20) :: name='c_bjac_precdescr'
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -154,17 +155,25 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
 
     if (.not.allocated(prec%iprcparm)) then 
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
       goto 9999
     end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
-    
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Block Jacobi with: ',&
+    if (root_ == -1) root_ = iam
+
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Block Jacobi with: ',&
          &  fact_names(prec%iprcparm(psb_f_type_))
     
     call psb_erractionrestore(err_act)
diff --git a/prec/psb_c_diagprec.f90 b/prec/psb_c_diagprec.f90
index 3a1b5af9..a8267070 100644
--- a/prec/psb_c_diagprec.f90
+++ b/prec/psb_c_diagprec.f90
@@ -160,18 +160,18 @@ contains
   end subroutine psb_c_diag_precfree
   
 
-  subroutine psb_c_diag_precdescr(prec,iout)
+  subroutine psb_c_diag_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     Implicit None
 
     class(psb_c_diag_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='c_diag_precdescr'
-
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -182,11 +182,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+    
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+  
+    if (root_ == -1) root_ = iam
     
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Diagonal scaling'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Diagonal scaling'
 
     call psb_erractionsave(err_act)
 
diff --git a/prec/psb_c_nullprec.f90 b/prec/psb_c_nullprec.f90
index 59e71ce7..5304bff1 100644
--- a/prec/psb_c_nullprec.f90
+++ b/prec/psb_c_nullprec.f90
@@ -156,7 +156,7 @@ contains
   end subroutine psb_c_null_precfree
   
 
-  subroutine psb_c_null_precdescr(prec,iout)
+  subroutine psb_c_null_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     
@@ -164,10 +164,13 @@ contains
 
     class(psb_c_null_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='c_null_precset'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=32) :: dprefix, frmtv
+    integer(psb_ipk_) :: ni
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -178,11 +181,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+    if (root_ == -1) root_ = iam
+
 
-    if (iam == psb_root_) &
-         & write(iout_,*) 'No preconditioning'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'No preconditioning'
 
     call psb_erractionrestore(err_act)
     return
diff --git a/prec/psb_c_prec_type.f90 b/prec/psb_c_prec_type.f90
index 112acd8d..bace774a 100644
--- a/prec/psb_c_prec_type.f90
+++ b/prec/psb_c_prec_type.f90
@@ -148,11 +148,12 @@ module psb_c_prec_type
   
 contains
 
-  subroutine psb_cfile_prec_descr(prec,iout)
+  subroutine psb_cfile_prec_descr(prec,iout, root)
     use psb_base_mod
     implicit none 
     class(psb_cprec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
     integer(psb_ipk_) :: iout_,info
     character(len=20) :: name='prec_descr' 
     
@@ -166,7 +167,7 @@ contains
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
     end if
-    call prec%prec%descr(iout)
+    call prec%prec%descr(iout=iout,root=root)
     
   end subroutine psb_cfile_prec_descr
 
diff --git a/prec/psb_d_base_prec_mod.f90 b/prec/psb_d_base_prec_mod.f90
index 4bc18ec0..94550aa9 100644
--- a/prec/psb_d_base_prec_mod.f90
+++ b/prec/psb_d_base_prec_mod.f90
@@ -60,6 +60,7 @@ module psb_d_base_prec_mod
     generic, public       :: apply     => d_apply, d_apply_v
     generic, public       :: build     => precbld
     generic, public       :: descr     => precdescr
+    procedure, pass(prec) :: desc_prefix => psb_d_base_desc_prefix
     procedure(psb_d_base_precbld), pass(prec), deferred :: precbld    
     procedure(psb_d_base_sizeof), pass(prec), deferred :: sizeof     
     procedure(psb_d_base_precinit), pass(prec), deferred :: precinit   
@@ -156,7 +157,7 @@ module psb_d_base_prec_mod
 
 
   abstract interface 
-    subroutine psb_d_base_precdescr(prec,iout)
+    subroutine psb_d_base_precdescr(prec,iout,root)
       import psb_ipk_, psb_dpk_, psb_desc_type, psb_d_vect_type, &
            & psb_d_base_vect_type, psb_dspmat_type, psb_d_base_prec_type,&
            & psb_d_base_sparse_mat
@@ -164,6 +165,7 @@ module psb_d_base_prec_mod
 
       class(psb_d_base_prec_type), intent(in) :: prec
       integer(psb_ipk_), intent(in), optional    :: iout
+      integer(psb_ipk_), intent(in), optional    :: root
 
     end subroutine psb_d_base_precdescr
   end interface
@@ -289,4 +291,27 @@ contains
 
   end function psb_d_base_get_nzeros
 
+  function psb_d_base_desc_prefix(prec) result(res)
+    use psb_base_mod, only : psb_info, psb_root_
+    implicit none 
+    class(psb_d_base_prec_type), intent(in) :: prec
+    character(len=32) :: res 
+    !
+    character(len=32) :: frmtv
+    integer(psb_ipk_) :: ni, ictxt,iam,np
+
+    ictxt = prec%ictxt
+    call psb_info(ictxt,iam,np)
+    
+    res = ''
+    if (iam /= psb_root_) then
+      ni  = floor(log10(1.0*np)) + 1
+      write(frmtv,'(a,i8.8,a)') '(a,i',ni,',a)'
+      write(res,frmtv) 'Process ',iam,': Preconditioner: '
+    else
+      write(res,'(a)') 'Preconditioner: '
+    end if
+
+  end function psb_d_base_desc_prefix
+
 end module psb_d_base_prec_mod
diff --git a/prec/psb_d_bjacprec.f90 b/prec/psb_d_bjacprec.f90
index de561415..ee2616c9 100644
--- a/prec/psb_d_bjacprec.f90
+++ b/prec/psb_d_bjacprec.f90
@@ -133,17 +133,18 @@ module psb_d_bjacprec
 
 contains
 
-  subroutine psb_d_bjac_precdescr(prec,iout)
+  subroutine psb_d_bjac_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     implicit none 
 
     class(psb_d_bjac_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
-    character(len=20)  :: name='d_bjac_precdescr'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=20) :: name='d_bjac_precdescr'
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -154,17 +155,25 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
 
     if (.not.allocated(prec%iprcparm)) then 
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
       goto 9999
     end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
-    
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Block Jacobi with: ',&
+    if (root_ == -1) root_ = iam
+
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Block Jacobi with: ',&
          &  fact_names(prec%iprcparm(psb_f_type_))
     
     call psb_erractionrestore(err_act)
diff --git a/prec/psb_d_diagprec.f90 b/prec/psb_d_diagprec.f90
index 2e6ef92d..227d4a04 100644
--- a/prec/psb_d_diagprec.f90
+++ b/prec/psb_d_diagprec.f90
@@ -160,18 +160,18 @@ contains
   end subroutine psb_d_diag_precfree
   
 
-  subroutine psb_d_diag_precdescr(prec,iout)
+  subroutine psb_d_diag_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     Implicit None
 
     class(psb_d_diag_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='d_diag_precdescr'
-
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -182,11 +182,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+    
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+  
+    if (root_ == -1) root_ = iam
     
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Diagonal scaling'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Diagonal scaling'
 
     call psb_erractionsave(err_act)
 
diff --git a/prec/psb_d_nullprec.f90 b/prec/psb_d_nullprec.f90
index acb03ec7..f9a3589e 100644
--- a/prec/psb_d_nullprec.f90
+++ b/prec/psb_d_nullprec.f90
@@ -156,7 +156,7 @@ contains
   end subroutine psb_d_null_precfree
   
 
-  subroutine psb_d_null_precdescr(prec,iout)
+  subroutine psb_d_null_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     
@@ -164,10 +164,13 @@ contains
 
     class(psb_d_null_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='d_null_precset'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=32) :: dprefix, frmtv
+    integer(psb_ipk_) :: ni
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -178,11 +181,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+    if (root_ == -1) root_ = iam
+
 
-    if (iam == psb_root_) &
-         & write(iout_,*) 'No preconditioning'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'No preconditioning'
 
     call psb_erractionrestore(err_act)
     return
diff --git a/prec/psb_d_prec_type.f90 b/prec/psb_d_prec_type.f90
index eb0fa5c8..97ec74b1 100644
--- a/prec/psb_d_prec_type.f90
+++ b/prec/psb_d_prec_type.f90
@@ -148,11 +148,12 @@ module psb_d_prec_type
   
 contains
 
-  subroutine psb_dfile_prec_descr(prec,iout)
+  subroutine psb_dfile_prec_descr(prec,iout, root)
     use psb_base_mod
     implicit none 
     class(psb_dprec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
     integer(psb_ipk_) :: iout_,info
     character(len=20) :: name='prec_descr' 
     
@@ -166,7 +167,7 @@ contains
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
     end if
-    call prec%prec%descr(iout)
+    call prec%prec%descr(iout=iout,root=root)
     
   end subroutine psb_dfile_prec_descr
 
diff --git a/prec/psb_s_base_prec_mod.f90 b/prec/psb_s_base_prec_mod.f90
index 46ff49fd..6440f703 100644
--- a/prec/psb_s_base_prec_mod.f90
+++ b/prec/psb_s_base_prec_mod.f90
@@ -60,6 +60,7 @@ module psb_s_base_prec_mod
     generic, public       :: apply     => s_apply, s_apply_v
     generic, public       :: build     => precbld
     generic, public       :: descr     => precdescr
+    procedure, pass(prec) :: desc_prefix => psb_s_base_desc_prefix
     procedure(psb_s_base_precbld), pass(prec), deferred :: precbld    
     procedure(psb_s_base_sizeof), pass(prec), deferred :: sizeof     
     procedure(psb_s_base_precinit), pass(prec), deferred :: precinit   
@@ -156,7 +157,7 @@ module psb_s_base_prec_mod
 
 
   abstract interface 
-    subroutine psb_s_base_precdescr(prec,iout)
+    subroutine psb_s_base_precdescr(prec,iout,root)
       import psb_ipk_, psb_spk_, psb_desc_type, psb_s_vect_type, &
            & psb_s_base_vect_type, psb_sspmat_type, psb_s_base_prec_type,&
            & psb_s_base_sparse_mat
@@ -164,6 +165,7 @@ module psb_s_base_prec_mod
 
       class(psb_s_base_prec_type), intent(in) :: prec
       integer(psb_ipk_), intent(in), optional    :: iout
+      integer(psb_ipk_), intent(in), optional    :: root
 
     end subroutine psb_s_base_precdescr
   end interface
@@ -289,4 +291,27 @@ contains
 
   end function psb_s_base_get_nzeros
 
+  function psb_s_base_desc_prefix(prec) result(res)
+    use psb_base_mod, only : psb_info, psb_root_
+    implicit none 
+    class(psb_s_base_prec_type), intent(in) :: prec
+    character(len=32) :: res 
+    !
+    character(len=32) :: frmtv
+    integer(psb_ipk_) :: ni, ictxt,iam,np
+
+    ictxt = prec%ictxt
+    call psb_info(ictxt,iam,np)
+    
+    res = ''
+    if (iam /= psb_root_) then
+      ni  = floor(log10(1.0*np)) + 1
+      write(frmtv,'(a,i8.8,a)') '(a,i',ni,',a)'
+      write(res,frmtv) 'Process ',iam,': Preconditioner: '
+    else
+      write(res,'(a)') 'Preconditioner: '
+    end if
+
+  end function psb_s_base_desc_prefix
+
 end module psb_s_base_prec_mod
diff --git a/prec/psb_s_bjacprec.f90 b/prec/psb_s_bjacprec.f90
index f07d023a..e8ec9b86 100644
--- a/prec/psb_s_bjacprec.f90
+++ b/prec/psb_s_bjacprec.f90
@@ -133,17 +133,18 @@ module psb_s_bjacprec
 
 contains
 
-  subroutine psb_s_bjac_precdescr(prec,iout)
+  subroutine psb_s_bjac_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     implicit none 
 
     class(psb_s_bjac_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
-    character(len=20)  :: name='s_bjac_precdescr'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=20) :: name='s_bjac_precdescr'
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -154,17 +155,25 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
 
     if (.not.allocated(prec%iprcparm)) then 
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
       goto 9999
     end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
-    
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Block Jacobi with: ',&
+    if (root_ == -1) root_ = iam
+
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Block Jacobi with: ',&
          &  fact_names(prec%iprcparm(psb_f_type_))
     
     call psb_erractionrestore(err_act)
diff --git a/prec/psb_s_diagprec.f90 b/prec/psb_s_diagprec.f90
index a97e18d7..cf7c5991 100644
--- a/prec/psb_s_diagprec.f90
+++ b/prec/psb_s_diagprec.f90
@@ -160,18 +160,18 @@ contains
   end subroutine psb_s_diag_precfree
   
 
-  subroutine psb_s_diag_precdescr(prec,iout)
+  subroutine psb_s_diag_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     Implicit None
 
     class(psb_s_diag_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='s_diag_precdescr'
-
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -182,11 +182,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+    
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+  
+    if (root_ == -1) root_ = iam
     
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Diagonal scaling'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Diagonal scaling'
 
     call psb_erractionsave(err_act)
 
diff --git a/prec/psb_s_nullprec.f90 b/prec/psb_s_nullprec.f90
index 453b7716..8247573d 100644
--- a/prec/psb_s_nullprec.f90
+++ b/prec/psb_s_nullprec.f90
@@ -156,7 +156,7 @@ contains
   end subroutine psb_s_null_precfree
   
 
-  subroutine psb_s_null_precdescr(prec,iout)
+  subroutine psb_s_null_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     
@@ -164,10 +164,13 @@ contains
 
     class(psb_s_null_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='s_null_precset'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=32) :: dprefix, frmtv
+    integer(psb_ipk_) :: ni
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -178,11 +181,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+    if (root_ == -1) root_ = iam
+
 
-    if (iam == psb_root_) &
-         & write(iout_,*) 'No preconditioning'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'No preconditioning'
 
     call psb_erractionrestore(err_act)
     return
diff --git a/prec/psb_s_prec_type.f90 b/prec/psb_s_prec_type.f90
index ef4ffc21..957e6f17 100644
--- a/prec/psb_s_prec_type.f90
+++ b/prec/psb_s_prec_type.f90
@@ -148,11 +148,12 @@ module psb_s_prec_type
   
 contains
 
-  subroutine psb_sfile_prec_descr(prec,iout)
+  subroutine psb_sfile_prec_descr(prec,iout, root)
     use psb_base_mod
     implicit none 
     class(psb_sprec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
     integer(psb_ipk_) :: iout_,info
     character(len=20) :: name='prec_descr' 
     
@@ -166,7 +167,7 @@ contains
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
     end if
-    call prec%prec%descr(iout)
+    call prec%prec%descr(iout=iout,root=root)
     
   end subroutine psb_sfile_prec_descr
 
diff --git a/prec/psb_z_base_prec_mod.f90 b/prec/psb_z_base_prec_mod.f90
index 05e37358..3507f9dc 100644
--- a/prec/psb_z_base_prec_mod.f90
+++ b/prec/psb_z_base_prec_mod.f90
@@ -60,6 +60,7 @@ module psb_z_base_prec_mod
     generic, public       :: apply     => z_apply, z_apply_v
     generic, public       :: build     => precbld
     generic, public       :: descr     => precdescr
+    procedure, pass(prec) :: desc_prefix => psb_z_base_desc_prefix
     procedure(psb_z_base_precbld), pass(prec), deferred :: precbld    
     procedure(psb_z_base_sizeof), pass(prec), deferred :: sizeof     
     procedure(psb_z_base_precinit), pass(prec), deferred :: precinit   
@@ -156,7 +157,7 @@ module psb_z_base_prec_mod
 
 
   abstract interface 
-    subroutine psb_z_base_precdescr(prec,iout)
+    subroutine psb_z_base_precdescr(prec,iout,root)
       import psb_ipk_, psb_dpk_, psb_desc_type, psb_z_vect_type, &
            & psb_z_base_vect_type, psb_zspmat_type, psb_z_base_prec_type,&
            & psb_z_base_sparse_mat
@@ -164,6 +165,7 @@ module psb_z_base_prec_mod
 
       class(psb_z_base_prec_type), intent(in) :: prec
       integer(psb_ipk_), intent(in), optional    :: iout
+      integer(psb_ipk_), intent(in), optional    :: root
 
     end subroutine psb_z_base_precdescr
   end interface
@@ -289,4 +291,27 @@ contains
 
   end function psb_z_base_get_nzeros
 
+  function psb_z_base_desc_prefix(prec) result(res)
+    use psb_base_mod, only : psb_info, psb_root_
+    implicit none 
+    class(psb_z_base_prec_type), intent(in) :: prec
+    character(len=32) :: res 
+    !
+    character(len=32) :: frmtv
+    integer(psb_ipk_) :: ni, ictxt,iam,np
+
+    ictxt = prec%ictxt
+    call psb_info(ictxt,iam,np)
+    
+    res = ''
+    if (iam /= psb_root_) then
+      ni  = floor(log10(1.0*np)) + 1
+      write(frmtv,'(a,i8.8,a)') '(a,i',ni,',a)'
+      write(res,frmtv) 'Process ',iam,': Preconditioner: '
+    else
+      write(res,'(a)') 'Preconditioner: '
+    end if
+
+  end function psb_z_base_desc_prefix
+
 end module psb_z_base_prec_mod
diff --git a/prec/psb_z_bjacprec.f90 b/prec/psb_z_bjacprec.f90
index 64ede43d..2c63b002 100644
--- a/prec/psb_z_bjacprec.f90
+++ b/prec/psb_z_bjacprec.f90
@@ -133,17 +133,18 @@ module psb_z_bjacprec
 
 contains
 
-  subroutine psb_z_bjac_precdescr(prec,iout)
+  subroutine psb_z_bjac_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     implicit none 
 
     class(psb_z_bjac_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
-    character(len=20)  :: name='z_bjac_precdescr'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=20) :: name='z_bjac_precdescr'
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -154,17 +155,25 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
 
     if (.not.allocated(prec%iprcparm)) then 
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
       goto 9999
     end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
-    
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Block Jacobi with: ',&
+    if (root_ == -1) root_ = iam
+
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Block Jacobi with: ',&
          &  fact_names(prec%iprcparm(psb_f_type_))
     
     call psb_erractionrestore(err_act)
diff --git a/prec/psb_z_diagprec.f90 b/prec/psb_z_diagprec.f90
index db2569f0..7ddc168a 100644
--- a/prec/psb_z_diagprec.f90
+++ b/prec/psb_z_diagprec.f90
@@ -160,18 +160,18 @@ contains
   end subroutine psb_z_diag_precfree
   
 
-  subroutine psb_z_diag_precdescr(prec,iout)
+  subroutine psb_z_diag_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     Implicit None
 
     class(psb_z_diag_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='z_diag_precdescr'
-
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -182,11 +182,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+    
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+  
+    if (root_ == -1) root_ = iam
     
-    if (iam == psb_root_) &
-         & write(iout_,*) 'Diagonal scaling'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'Diagonal scaling'
 
     call psb_erractionsave(err_act)
 
diff --git a/prec/psb_z_nullprec.f90 b/prec/psb_z_nullprec.f90
index 7e69de01..d8c4f0ab 100644
--- a/prec/psb_z_nullprec.f90
+++ b/prec/psb_z_nullprec.f90
@@ -156,7 +156,7 @@ contains
   end subroutine psb_z_null_precfree
   
 
-  subroutine psb_z_null_precdescr(prec,iout)
+  subroutine psb_z_null_precdescr(prec,iout,root)
     use psb_penv_mod
     use psb_error_mod
     
@@ -164,10 +164,13 @@ contains
 
     class(psb_z_null_prec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
 
     integer(psb_ipk_) :: err_act, nrow, info
     character(len=20)  :: name='z_null_precset'
-    integer(psb_ipk_) :: iout_, ictxt, iam, np 
+    character(len=32) :: dprefix, frmtv
+    integer(psb_ipk_) :: ni
+    integer(psb_ipk_) :: iout_, ictxt, iam, np, root_
 
     call psb_erractionsave(err_act)
 
@@ -178,11 +181,20 @@ contains
     else
       iout_ = 6 
     end if
+    if (present(root)) then 
+      root_ = root
+    else
+      root_ = psb_root_
+    end if
+
     ictxt = prec%ictxt
     call psb_info(ictxt,iam,np)
+    if (root_ == -1) root_ = iam
+
 
-    if (iam == psb_root_) &
-         & write(iout_,*) 'No preconditioning'
+    if (iam == root_) &
+         &  write(iout_,*) trim(prec%desc_prefix()),' ',&
+         & 'No preconditioning'
 
     call psb_erractionrestore(err_act)
     return
diff --git a/prec/psb_z_prec_type.f90 b/prec/psb_z_prec_type.f90
index 680c2a70..09141385 100644
--- a/prec/psb_z_prec_type.f90
+++ b/prec/psb_z_prec_type.f90
@@ -148,11 +148,12 @@ module psb_z_prec_type
   
 contains
 
-  subroutine psb_zfile_prec_descr(prec,iout)
+  subroutine psb_zfile_prec_descr(prec,iout, root)
     use psb_base_mod
     implicit none 
     class(psb_zprec_type), intent(in) :: prec
     integer(psb_ipk_), intent(in), optional    :: iout
+    integer(psb_ipk_), intent(in), optional    :: root
     integer(psb_ipk_) :: iout_,info
     character(len=20) :: name='prec_descr' 
     
@@ -166,7 +167,7 @@ contains
       info = 1124
       call psb_errpush(info,name,a_err="preconditioner")
     end if
-    call prec%prec%descr(iout)
+    call prec%prec%descr(iout=iout,root=root)
     
   end subroutine psb_zfile_prec_descr
 


 
$res$
 $x$
 Subroutine