[openib-general] [PATCH v3 3/3] ofed_1_2 Provide generic allocator backport to 2.6.20.

[Steve WIse]

On Sat, 2007-01-13 at 23:13 +0200, Michael S. Tsirkin wrote:
> > Quoting Steve Wise <swise at opengridcomputing.com>:
> > Subject: [PATCH  v3 3/3] ofed_1_2 Provide generic allocator backport to 2.6.20.
> > 
> > 
> > This is needed even on kernels that might have genalloc because it
> > may not be configured into the running kernel.  Right now the only
> > subsystem that turns on the generic allocator config option is IA64.
> > So chances are good that 2.6.20 kernels will _not_ have this compiled in.
> > So we just backport it to all supported kernels.
> > 
> > To avoid collisions with kernels that _do_ have this compiled in, 
> > change the names of the exported symbols in the backport.
> > 
> > Changes to genalloc.c:
> > 
> > - Change exported symbol names by prepending ib_
> >   EG: gen_pool_alloc() becomes ib_gen_pool_alloc()
> > 
> > Changes to genalloc.h:
> > 
> > - Change exported symbol names by prepending ib_
> > - added #defines for original exported symbol names to new names. Thus
> >   code calling the allocator doesn't need to change.
> > 
> >   EG: #define gen_pool_alloc ib_gen_pool alloc
> > 
> > Signed-off-by: Steve Wise <swise at opengridcomputing.com>
> > ---
> > 
> >  .../backport/2.6.20/include/linux/genalloc.h       |   42 +++++
> >  .../backport/2.6.20/include/src/genalloc.c         |  198 +++++++++++++++++++++++
> >  .../backport/2.6.20/linux_genalloc_to_2.6.20.patch |   18 ++
> >  3 files changed, 258 insertions(+), 0 deletions(-)
> > 
> > diff --git a/kernel_addons/backport/2.6.20/include/linux/genalloc.h b/kernel_addons/backport/2.6.20/include/linux/genalloc.h
> > new file mode 100644
> > index 0000000..3c23c68
> > --- /dev/null
> > +++ b/kernel_addons/backport/2.6.20/include/linux/genalloc.h
> > @@ -0,0 +1,42 @@
> > +/*
> > + * Basic general purpose allocator for managing special purpose memory
> > + * not managed by the regular kmalloc/kfree interface.
> > + * Uses for this includes on-device special memory, uncached memory
> > + * etc.
> > + *
> > + * This source code is licensed under the GNU General Public License,
> > + * Version 2.  See the file COPYING for more details.
> > + */
> > +
> > +
> > +/*
> > + *  General purpose special memory pool descriptor.
> > + */
> > +struct gen_pool {
> > +	rwlock_t lock;
> > +	struct list_head chunks;	/* list of chunks in this pool */
> > +	int min_alloc_order;		/* minimum allocation order */
> > +};
> > +
> > +/*
> > + *  General purpose special memory pool chunk descriptor.
> > + */
> > +struct gen_pool_chunk {
> > +	spinlock_t lock;
> > +	struct list_head next_chunk;	/* next chunk in pool */
> > +	unsigned long start_addr;	/* starting address of memory chunk */
> > +	unsigned long end_addr;		/* ending address of memory chunk */
> > +	unsigned long bits[0];		/* bitmap for allocating memory chunk */
> > +};
> > +
> > +extern struct gen_pool *ib_gen_pool_create(int, int);
> 
> If you think about it, by virtue of the defines above, genalloc.c
> can be included without change. Correct?
> 

I think you're right.  I'll fix this.

Thanks,

Steve.