Re: [PATCH v3 11/15] KVM: s390: stop using lists to keep track of used dat tables

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Wed, 22 Jan 2025 17:13:49 +0100
"Christoph Schlameuss" <schlameuss@linux.ibm.com> wrote:

> On Fri Jan 17, 2025 at 8:09 PM CET, Claudio Imbrenda wrote:
> > Until now, every dat table allocated to map a guest was put in a
> > linked list. The page->lru field of struct page was used to keep track
> > of which pages were being used, and when the gmap is torn down, the
> > list was walked and all pages freed.
> >
> > This patch gets rid of the usage of page->lru. Page tables are now
> > freed by recursively walking the dat table tree.
> >
> > Since s390_unlist_old_asce() becomes useless now, remove it.
> >
> > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>  
> 
> With comment fixes done:
> 
> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
> 
> > ---
> >  arch/s390/include/asm/gmap.h |   3 --
> >  arch/s390/mm/gmap.c          | 102 ++++++++---------------------------
> >  2 files changed, 23 insertions(+), 82 deletions(-)
> >
> > diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
> > index dbf2329281d2..904d97f0bc5e 100644
> > --- a/arch/s390/include/asm/gmap.h
> > +++ b/arch/s390/include/asm/gmap.h
> > @@ -45,7 +45,6 @@
> >   */
> >  struct gmap {
> >  	struct list_head list;
> > -	struct list_head crst_list;  
> 
> nit: Please also remove @crst_list and @pt_list from the struct gmap comment.

ouch yes, definitely

> 
> >  	struct mm_struct *mm;
> >  	struct radix_tree_root guest_to_host;
> >  	struct radix_tree_root host_to_guest;
> > @@ -61,7 +60,6 @@ struct gmap {
> >  	/* Additional data for shadow guest address spaces */
> >  	struct radix_tree_root host_to_rmap;
> >  	struct list_head children;
> > -	struct list_head pt_list;
> >  	spinlock_t shadow_lock;
> >  	struct gmap *parent;
> >  	unsigned long orig_asce;
> > @@ -141,7 +139,6 @@ int gmap_protect_one(struct gmap *gmap, unsigned long gaddr, int prot, unsigned
> >  void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
> >  			     unsigned long gaddr, unsigned long vmaddr);
> >  int s390_disable_cow_sharing(void);
> > -void s390_unlist_old_asce(struct gmap *gmap);
> >  int s390_replace_asce(struct gmap *gmap);
> >  void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
> >  int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,  
> 
> [...]
>