| Message ID | 20231119165721.9849-5-alexandru.elisei@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,v2,01/27] arm64: mte: Rework naming for tag manipulation functions | expand |
On Sun, Nov 19, 2023 at 04:56:58PM +0000, Alexandru Elisei wrote: > It might be desirable for an architecture to modify the gfp flags used to > allocate the destination page for migration based on the page that it is > being replaced. For example, if an architectures has metadata associated > with a page (like arm64, when the memory tagging extension is implemented), > it can request that the destination page similarly has storage for tags > already allocated. > > No functional change. > > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> > --- > include/linux/migrate.h | 4 ++++ > mm/mempolicy.c | 2 ++ > mm/migrate.c | 3 +++ > 3 files changed, 9 insertions(+) > > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > index 2ce13e8a309b..0acef592043c 100644 > --- a/include/linux/migrate.h > +++ b/include/linux/migrate.h > @@ -60,6 +60,10 @@ struct movable_operations { > /* Defined in mm/debug.c: */ > extern const char *migrate_reason_names[MR_TYPES]; > > +#ifndef arch_migration_target_gfp > +#define arch_migration_target_gfp(src, gfp) 0 > +#endif > + > #ifdef CONFIG_MIGRATION > > void putback_movable_pages(struct list_head *l); > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 10a590ee1c89..50bc43ab50d6 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -1182,6 +1182,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > h = folio_hstate(src); > gfp = htlb_alloc_mask(h); > + gfp |= arch_migration_target_gfp(src, gfp); I think it'll be more robust to have arch_migration_target_gfp() to modify the flags and return the new mask with added (or potentially removed) flags. > nodemask = policy_nodemask(gfp, pol, ilx, &nid); > return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp); > } > @@ -1190,6 +1191,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > gfp = GFP_TRANSHUGE; > else > gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP; > + gfp |= arch_migration_target_gfp(src, gfp); > > page = alloc_pages_mpol(gfp, order, pol, ilx, nid); > return page_rmappable_folio(page);
Hi Mike, I really appreciate you having a look! On Sat, Nov 25, 2023 at 12:03:22PM +0200, Mike Rapoport wrote: > On Sun, Nov 19, 2023 at 04:56:58PM +0000, Alexandru Elisei wrote: > > It might be desirable for an architecture to modify the gfp flags used to > > allocate the destination page for migration based on the page that it is > > being replaced. For example, if an architectures has metadata associated > > with a page (like arm64, when the memory tagging extension is implemented), > > it can request that the destination page similarly has storage for tags > > already allocated. > > > > No functional change. > > > > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> > > --- > > include/linux/migrate.h | 4 ++++ > > mm/mempolicy.c | 2 ++ > > mm/migrate.c | 3 +++ > > 3 files changed, 9 insertions(+) > > > > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > > index 2ce13e8a309b..0acef592043c 100644 > > --- a/include/linux/migrate.h > > +++ b/include/linux/migrate.h > > @@ -60,6 +60,10 @@ struct movable_operations { > > /* Defined in mm/debug.c: */ > > extern const char *migrate_reason_names[MR_TYPES]; > > > > +#ifndef arch_migration_target_gfp > > +#define arch_migration_target_gfp(src, gfp) 0 > > +#endif > > + > > #ifdef CONFIG_MIGRATION > > > > void putback_movable_pages(struct list_head *l); > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > > index 10a590ee1c89..50bc43ab50d6 100644 > > --- a/mm/mempolicy.c > > +++ b/mm/mempolicy.c > > @@ -1182,6 +1182,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > > > h = folio_hstate(src); > > gfp = htlb_alloc_mask(h); > > + gfp |= arch_migration_target_gfp(src, gfp); > > I think it'll be more robust to have arch_migration_target_gfp() to modify > the flags and return the new mask with added (or potentially removed) > flags. I did it this way so an arch won't be able to remove flags set by the MM code. There's a similar pattern in do_mmap() -> calc_vm_flag_bits() -> arch_calc_vm_flag_bits(). I'll change it to return the new mask if you think that's better. Thanks, Alex > > > nodemask = policy_nodemask(gfp, pol, ilx, &nid); > > return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp); > > } > > @@ -1190,6 +1191,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > gfp = GFP_TRANSHUGE; > > else > > gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP; > > + gfp |= arch_migration_target_gfp(src, gfp); > > > > page = alloc_pages_mpol(gfp, order, pol, ilx, nid); > > return page_rmappable_folio(page); > > -- > Sincerely yours, > Mike. >
On Mon, Nov 27, 2023 at 11:52:56AM +0000, Alexandru Elisei wrote: > Hi Mike, > > I really appreciate you having a look! > > On Sat, Nov 25, 2023 at 12:03:22PM +0200, Mike Rapoport wrote: > > On Sun, Nov 19, 2023 at 04:56:58PM +0000, Alexandru Elisei wrote: > > > It might be desirable for an architecture to modify the gfp flags used to > > > allocate the destination page for migration based on the page that it is > > > being replaced. For example, if an architectures has metadata associated > > > with a page (like arm64, when the memory tagging extension is implemented), > > > it can request that the destination page similarly has storage for tags > > > already allocated. > > > > > > No functional change. > > > > > > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> > > > --- > > > include/linux/migrate.h | 4 ++++ > > > mm/mempolicy.c | 2 ++ > > > mm/migrate.c | 3 +++ > > > 3 files changed, 9 insertions(+) > > > > > > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > > > index 2ce13e8a309b..0acef592043c 100644 > > > --- a/include/linux/migrate.h > > > +++ b/include/linux/migrate.h > > > @@ -60,6 +60,10 @@ struct movable_operations { > > > /* Defined in mm/debug.c: */ > > > extern const char *migrate_reason_names[MR_TYPES]; > > > > > > +#ifndef arch_migration_target_gfp > > > +#define arch_migration_target_gfp(src, gfp) 0 > > > +#endif > > > + > > > #ifdef CONFIG_MIGRATION > > > > > > void putback_movable_pages(struct list_head *l); > > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > > > index 10a590ee1c89..50bc43ab50d6 100644 > > > --- a/mm/mempolicy.c > > > +++ b/mm/mempolicy.c > > > @@ -1182,6 +1182,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > > > > > h = folio_hstate(src); > > > gfp = htlb_alloc_mask(h); > > > + gfp |= arch_migration_target_gfp(src, gfp); > > > > I think it'll be more robust to have arch_migration_target_gfp() to modify > > the flags and return the new mask with added (or potentially removed) > > flags. > > I did it this way so an arch won't be able to remove flags set by the MM code. > There's a similar pattern in do_mmap() -> calc_vm_flag_bits() -> > arch_calc_vm_flag_bits(). Ok, just add a sentence about it to the commit message. > Thanks, > Alex > > > > > > nodemask = policy_nodemask(gfp, pol, ilx, &nid); > > > return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp); > > > } > > > @@ -1190,6 +1191,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > > gfp = GFP_TRANSHUGE; > > > else > > > gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP; > > > + gfp |= arch_migration_target_gfp(src, gfp); > > > > > > page = alloc_pages_mpol(gfp, order, pol, ilx, nid); > > > return page_rmappable_folio(page); > > > > -- > > Sincerely yours, > > Mike. > >
Hi, On Tue, Nov 28, 2023 at 08:49:57AM +0200, Mike Rapoport wrote: > On Mon, Nov 27, 2023 at 11:52:56AM +0000, Alexandru Elisei wrote: > > Hi Mike, > > > > I really appreciate you having a look! > > > > On Sat, Nov 25, 2023 at 12:03:22PM +0200, Mike Rapoport wrote: > > > On Sun, Nov 19, 2023 at 04:56:58PM +0000, Alexandru Elisei wrote: > > > > It might be desirable for an architecture to modify the gfp flags used to > > > > allocate the destination page for migration based on the page that it is > > > > being replaced. For example, if an architectures has metadata associated > > > > with a page (like arm64, when the memory tagging extension is implemented), > > > > it can request that the destination page similarly has storage for tags > > > > already allocated. > > > > > > > > No functional change. > > > > > > > > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> > > > > --- > > > > include/linux/migrate.h | 4 ++++ > > > > mm/mempolicy.c | 2 ++ > > > > mm/migrate.c | 3 +++ > > > > 3 files changed, 9 insertions(+) > > > > > > > > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > > > > index 2ce13e8a309b..0acef592043c 100644 > > > > --- a/include/linux/migrate.h > > > > +++ b/include/linux/migrate.h > > > > @@ -60,6 +60,10 @@ struct movable_operations { > > > > /* Defined in mm/debug.c: */ > > > > extern const char *migrate_reason_names[MR_TYPES]; > > > > > > > > +#ifndef arch_migration_target_gfp > > > > +#define arch_migration_target_gfp(src, gfp) 0 > > > > +#endif > > > > + > > > > #ifdef CONFIG_MIGRATION > > > > > > > > void putback_movable_pages(struct list_head *l); > > > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > > > > index 10a590ee1c89..50bc43ab50d6 100644 > > > > --- a/mm/mempolicy.c > > > > +++ b/mm/mempolicy.c > > > > @@ -1182,6 +1182,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > > > > > > > h = folio_hstate(src); > > > > gfp = htlb_alloc_mask(h); > > > > + gfp |= arch_migration_target_gfp(src, gfp); > > > > > > I think it'll be more robust to have arch_migration_target_gfp() to modify > > > the flags and return the new mask with added (or potentially removed) > > > flags. > > > > I did it this way so an arch won't be able to remove flags set by the MM code. > > There's a similar pattern in do_mmap() -> calc_vm_flag_bits() -> > > arch_calc_vm_flag_bits(). > > Ok, just add a sentence about it to the commit message. Great, will do that! Thanks, Alex > > > Thanks, > > Alex > > > > > > > > > nodemask = policy_nodemask(gfp, pol, ilx, &nid); > > > > return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp); > > > > } > > > > @@ -1190,6 +1191,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, > > > > gfp = GFP_TRANSHUGE; > > > > else > > > > gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP; > > > > + gfp |= arch_migration_target_gfp(src, gfp); > > > > > > > > page = alloc_pages_mpol(gfp, order, pol, ilx, nid); > > > > return page_rmappable_folio(page); > > > > > > -- > > > Sincerely yours, > > > Mike. > > > > > -- > Sincerely yours, > Mike. >
diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 2ce13e8a309b..0acef592043c 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -60,6 +60,10 @@ struct movable_operations { /* Defined in mm/debug.c: */ extern const char *migrate_reason_names[MR_TYPES]; +#ifndef arch_migration_target_gfp +#define arch_migration_target_gfp(src, gfp) 0 +#endif + #ifdef CONFIG_MIGRATION void putback_movable_pages(struct list_head *l); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 10a590ee1c89..50bc43ab50d6 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1182,6 +1182,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, h = folio_hstate(src); gfp = htlb_alloc_mask(h); + gfp |= arch_migration_target_gfp(src, gfp); nodemask = policy_nodemask(gfp, pol, ilx, &nid); return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp); } @@ -1190,6 +1191,7 @@ static struct folio *alloc_migration_target_by_mpol(struct folio *src, gfp = GFP_TRANSHUGE; else gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP; + gfp |= arch_migration_target_gfp(src, gfp); page = alloc_pages_mpol(gfp, order, pol, ilx, nid); return page_rmappable_folio(page); diff --git a/mm/migrate.c b/mm/migrate.c index 35a88334bb3c..dd25ab69e3de 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2016,6 +2016,7 @@ struct folio *alloc_migration_target(struct folio *src, unsigned long private) struct hstate *h = folio_hstate(src); gfp_mask = htlb_modify_alloc_mask(h, gfp_mask); + gfp_mask |= arch_migration_target_gfp(src, gfp); return alloc_hugetlb_folio_nodemask(h, nid, mtc->nmask, gfp_mask); } @@ -2032,6 +2033,7 @@ struct folio *alloc_migration_target(struct folio *src, unsigned long private) zidx = zone_idx(folio_zone(src)); if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE) gfp_mask |= __GFP_HIGHMEM; + gfp_mask |= arch_migration_target_gfp(src, gfp); return __folio_alloc(gfp_mask, order, nid, mtc->nmask); } @@ -2500,6 +2502,7 @@ static struct folio *alloc_misplaced_dst_folio(struct folio *src, __GFP_NOWARN; gfp &= ~__GFP_RECLAIM; } + gfp |= arch_migration_target_gfp(src, gfp); return __folio_alloc_node(gfp, order, nid); }
It might be desirable for an architecture to modify the gfp flags used to allocate the destination page for migration based on the page that it is being replaced. For example, if an architectures has metadata associated with a page (like arm64, when the memory tagging extension is implemented), it can request that the destination page similarly has storage for tags already allocated. No functional change. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> --- include/linux/migrate.h | 4 ++++ mm/mempolicy.c | 2 ++ mm/migrate.c | 3 +++ 3 files changed, 9 insertions(+)