Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-19 Thread Thomas Koenig
Hi Steve, On Sun, Jul 14, 2019 at 12:07:58PM +0200, Thomas Koenig wrote: OK, so here is a new version. I think the discussion has shown that enlaring the buffer makes sense, and that the buffer size for unformatted seems to be too bad. I've reversed the names of the environment variables acco

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-14 Thread Steve Kargl
On Sun, Jul 14, 2019 at 12:07:58PM +0200, Thomas Koenig wrote: > OK, so here is a new version. > > I think the discussion has shown that enlaring the buffer makes sense, > and that the buffer size for unformatted seems to be too bad. > > I've reversed the names of the environment variables accord

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-14 Thread Thomas Koenig
... of course, better with the actual patch. Index: gcc/fortran/gfortran.texi === --- gcc/fortran/gfortran.texi (Revision 273183) +++ gcc/fortran/gfortran.texi (Arbeitskopie) @@ -611,6 +611,8 @@ Malformed environment variables are si

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-14 Thread Thomas Koenig
OK, so here is a new version. I think the discussion has shown that enlaring the buffer makes sense, and that the buffer size for unformatted seems to be too bad. I've reversed the names of the environment variables according to Behnard's suggestion. So, OK for trunk? Also, what should we do a

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-09 Thread Bernhard Reutner-Fischer
On Mon, 8 Jul 2019 09:05:04 -0700 Steve Kargl wrote: > On Mon, Jul 08, 2019 at 04:02:17PM +0300, Janne Blomqvist wrote: > > > > Good point. If you happen to have a USB stick handy, can you try the > > simple C benchmark program at > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91030#c38 ? > >

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-08 Thread Steve Kargl
On Mon, Jul 08, 2019 at 04:02:17PM +0300, Janne Blomqvist wrote: > > Good point. If you happen to have a USB stick handy, can you try the > simple C benchmark program at > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91030#c38 ? > > (the kernel will coalesce IO's by itself, so the granularity of

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-08 Thread Janne Blomqvist
On Sun, Jul 7, 2019 at 11:13 PM Thomas Koenig wrote: > > Hello world, > > the attached patch sets the I/O block size for unformatted files to > 2**17 and makes this, and the block size for formatted files, > adjustable via environment variables. Should the default be affected by the page size (sy

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-08 Thread Janne Blomqvist
On Mon, Jul 8, 2019 at 11:18 AM Manfred Schwarb wrote: > > Am 07.07.19 um 22:13 schrieb Thomas Koenig: > > Hello world, > > > > the attached patch sets the I/O block size for unformatted files to > > 2**17 and makes this, and the block size for formatted files, > > adjustable via environment varia

Re: [patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-08 Thread Manfred Schwarb
Am 07.07.19 um 22:13 schrieb Thomas Koenig: > Hello world, > > the attached patch sets the I/O block size for unformatted files to > 2**17 and makes this, and the block size for formatted files, > adjustable via environment variables. > > The main reason is that -fconvert=big-endian was quite slow

[patch, libfortran] Adjust block size for libgfortran for unformatted reads

2019-07-07 Thread Thomas Koenig
Hello world, the attached patch sets the I/O block size for unformatted files to 2**17 and makes this, and the block size for formatted files, adjustable via environment variables. The main reason is that -fconvert=big-endian was quite slow on some HPC systems. A bigger buffer should eliminate t