| Message ID | 20230310103210.22372-5-vbabka@suse.cz (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | remove SLOB and allow kfree() with kmem_cache_alloc() | expand |
On Fri, Mar 10, 2023 at 11:32:06AM +0100, Vlastimil Babka wrote: > SLOB has been removed and SLQB never merged, so remove their mentions > from comments and documentation of pagemap. > > Signed-off-by: Vlastimil Babka <vbabka@suse.cz> > --- > Documentation/admin-guide/mm/pagemap.rst | 6 +++--- > fs/proc/page.c | 5 ++--- > 2 files changed, 5 insertions(+), 6 deletions(-) > > diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst > index b5f970dc91e7..bb4aa897a773 100644 > --- a/Documentation/admin-guide/mm/pagemap.rst > +++ b/Documentation/admin-guide/mm/pagemap.rst > @@ -91,9 +91,9 @@ Short descriptions to the page flags > The page is being locked for exclusive access, e.g. by undergoing read/write > IO. > 7 - SLAB > - The page is managed by the SLAB/SLOB/SLUB/SLQB kernel memory allocator. > - When compound page is used, SLUB/SLQB will only set this flag on the head > - page; SLOB will not flag it at all. > + The page is managed by the SLAB/SLUB kernel memory allocator. > + When compound page is used, either will only set this flag on the head > + page.. > 10 - BUDDY > A free memory block managed by the buddy system allocator. > The buddy system organizes free memory in blocks of various orders. > diff --git a/fs/proc/page.c b/fs/proc/page.c > index 6249c347809a..1356aeffd8dc 100644 > --- a/fs/proc/page.c > +++ b/fs/proc/page.c > @@ -125,7 +125,7 @@ u64 stable_page_flags(struct page *page) > /* > * pseudo flags for the well known (anonymous) memory mapped pages > * > - * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the > + * Note that page->_mapcount is overloaded in SLAB/SLUB, so the SLUB does not overload _mapcount. > * simple test in page_mapped() is not enough. > */ > if (!PageSlab(page) && page_mapped(page)) > @@ -166,8 +166,7 @@ u64 stable_page_flags(struct page *page) > > /* > * Caveats on high order pages: page->_refcount will only be set > - * -1 on the head page; SLUB/SLQB do the same for PG_slab; > - * SLOB won't set PG_slab at all on compound pages. > + * -1 on the head page; SLAB/SLUB do the same for PG_slab; I think this comment could be just saying that PG_buddy is only set on head page, not saying _refcount is set to -1 on head page (is it even correct?) > */ > if (PageBuddy(page)) > u |= 1 << KPF_BUDDY; > -- > 2.39.2 >
On Fri, Mar 10, 2023 at 11:32:06AM +0100, Vlastimil Babka wrote: > SLOB has been removed and SLQB never merged, so remove their mentions > from comments and documentation of pagemap. > > Signed-off-by: Vlastimil Babka <vbabka@suse.cz> > --- > Documentation/admin-guide/mm/pagemap.rst | 6 +++--- > fs/proc/page.c | 5 ++--- > 2 files changed, 5 insertions(+), 6 deletions(-) > > diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst > index b5f970dc91e7..bb4aa897a773 100644 > --- a/Documentation/admin-guide/mm/pagemap.rst > +++ b/Documentation/admin-guide/mm/pagemap.rst > @@ -91,9 +91,9 @@ Short descriptions to the page flags > The page is being locked for exclusive access, e.g. by undergoing read/write > IO. > 7 - SLAB > - The page is managed by the SLAB/SLOB/SLUB/SLQB kernel memory allocator. > - When compound page is used, SLUB/SLQB will only set this flag on the head > - page; SLOB will not flag it at all. > + The page is managed by the SLAB/SLUB kernel memory allocator. > + When compound page is used, either will only set this flag on the head > + page.. I mean, perhaps the nittiest of nits but probably that '..' is unintended. > 10 - BUDDY > A free memory block managed by the buddy system allocator. > The buddy system organizes free memory in blocks of various orders. > diff --git a/fs/proc/page.c b/fs/proc/page.c > index 6249c347809a..1356aeffd8dc 100644 > --- a/fs/proc/page.c > +++ b/fs/proc/page.c > @@ -125,7 +125,7 @@ u64 stable_page_flags(struct page *page) > /* > * pseudo flags for the well known (anonymous) memory mapped pages > * > - * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the > + * Note that page->_mapcount is overloaded in SLAB/SLUB, so the > * simple test in page_mapped() is not enough. > */ > if (!PageSlab(page) && page_mapped(page)) > @@ -166,8 +166,7 @@ u64 stable_page_flags(struct page *page) > > /* > * Caveats on high order pages: page->_refcount will only be set > - * -1 on the head page; SLUB/SLQB do the same for PG_slab; > - * SLOB won't set PG_slab at all on compound pages. > + * -1 on the head page; SLAB/SLUB do the same for PG_slab; Nice catch on the redundant reference to the mysterous SLQB (+ above) :) > */ > if (PageBuddy(page)) > u |= 1 << KPF_BUDDY; > -- > 2.39.2 > Otherwise looks good to me, Acked-by: Lorenzo Stoakes <lstoakes@gmail.com>
On 3/14/23 09:19, Hyeonggon Yoo wrote: > On Fri, Mar 10, 2023 at 11:32:06AM +0100, Vlastimil Babka wrote: >> SLOB has been removed and SLQB never merged, so remove their mentions >> from comments and documentation of pagemap. >> >> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> >> --- >> Documentation/admin-guide/mm/pagemap.rst | 6 +++--- >> fs/proc/page.c | 5 ++--- >> 2 files changed, 5 insertions(+), 6 deletions(-) >> >> diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst >> index b5f970dc91e7..bb4aa897a773 100644 >> --- a/Documentation/admin-guide/mm/pagemap.rst >> +++ b/Documentation/admin-guide/mm/pagemap.rst >> @@ -91,9 +91,9 @@ Short descriptions to the page flags >> The page is being locked for exclusive access, e.g. by undergoing read/write >> IO. >> 7 - SLAB >> - The page is managed by the SLAB/SLOB/SLUB/SLQB kernel memory allocator. >> - When compound page is used, SLUB/SLQB will only set this flag on the head >> - page; SLOB will not flag it at all. >> + The page is managed by the SLAB/SLUB kernel memory allocator. >> + When compound page is used, either will only set this flag on the head >> + page.. >> 10 - BUDDY >> A free memory block managed by the buddy system allocator. >> The buddy system organizes free memory in blocks of various orders. >> diff --git a/fs/proc/page.c b/fs/proc/page.c >> index 6249c347809a..1356aeffd8dc 100644 >> --- a/fs/proc/page.c >> +++ b/fs/proc/page.c >> @@ -125,7 +125,7 @@ u64 stable_page_flags(struct page *page) >> /* >> * pseudo flags for the well known (anonymous) memory mapped pages >> * >> - * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the >> + * Note that page->_mapcount is overloaded in SLAB/SLUB, so the > > SLUB does not overload _mapcount. True, I overlooked that, thanks. >> * simple test in page_mapped() is not enough. >> */ >> if (!PageSlab(page) && page_mapped(page)) >> @@ -166,8 +166,7 @@ u64 stable_page_flags(struct page *page) >> >> /* >> * Caveats on high order pages: page->_refcount will only be set >> - * -1 on the head page; SLUB/SLQB do the same for PG_slab; >> - * SLOB won't set PG_slab at all on compound pages. >> + * -1 on the head page; SLAB/SLUB do the same for PG_slab; > > I think this comment could be just saying that PG_buddy is only set on > head page, not saying > > _refcount is set to -1 on head page (is it even correct?) It's not, that scheme is outdated. So I'll have it mention PG_buddy as you suggest, but PG_slab also needs special care as it's not set on tail pages. But I noticed the compound_head() is unnecessary as that's covered by PageSlab() which is defined as PF_NO_TAIL. So the sum of modifications to this patch: diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst index bb4aa897a773..c8f380271cad 100644 --- a/Documentation/admin-guide/mm/pagemap.rst +++ b/Documentation/admin-guide/mm/pagemap.rst @@ -93,7 +93,7 @@ Short descriptions to the page flags 7 - SLAB The page is managed by the SLAB/SLUB kernel memory allocator. When compound page is used, either will only set this flag on the head - page.. + page. 10 - BUDDY A free memory block managed by the buddy system allocator. The buddy system organizes free memory in blocks of various orders. diff --git a/fs/proc/page.c b/fs/proc/page.c index 1356aeffd8dc..195b077c0fac 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -125,7 +125,7 @@ u64 stable_page_flags(struct page *page) /* * pseudo flags for the well known (anonymous) memory mapped pages * - * Note that page->_mapcount is overloaded in SLAB/SLUB, so the + * Note that page->_mapcount is overloaded in SLAB, so the * simple test in page_mapped() is not enough. */ if (!PageSlab(page) && page_mapped(page)) @@ -165,8 +165,8 @@ u64 stable_page_flags(struct page *page) /* - * Caveats on high order pages: page->_refcount will only be set - * -1 on the head page; SLAB/SLUB do the same for PG_slab; + * Caveats on high order pages: PG_buddy and PG_slab will only be set + * on the head page. */ if (PageBuddy(page)) u |= 1 << KPF_BUDDY; @@ -184,7 +184,7 @@ u64 stable_page_flags(struct page *page) u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked); u |= kpf_copy_bit(k, KPF_SLAB, PG_slab); - if (PageTail(page) && PageSlab(compound_head(page))) + if (PageTail(page) && PageSlab(page)) u |= 1 << KPF_SLAB; u |= kpf_copy_bit(k, KPF_ERROR, PG_error);
diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst index b5f970dc91e7..bb4aa897a773 100644 --- a/Documentation/admin-guide/mm/pagemap.rst +++ b/Documentation/admin-guide/mm/pagemap.rst @@ -91,9 +91,9 @@ Short descriptions to the page flags The page is being locked for exclusive access, e.g. by undergoing read/write IO. 7 - SLAB - The page is managed by the SLAB/SLOB/SLUB/SLQB kernel memory allocator. - When compound page is used, SLUB/SLQB will only set this flag on the head - page; SLOB will not flag it at all. + The page is managed by the SLAB/SLUB kernel memory allocator. + When compound page is used, either will only set this flag on the head + page.. 10 - BUDDY A free memory block managed by the buddy system allocator. The buddy system organizes free memory in blocks of various orders. diff --git a/fs/proc/page.c b/fs/proc/page.c index 6249c347809a..1356aeffd8dc 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -125,7 +125,7 @@ u64 stable_page_flags(struct page *page) /* * pseudo flags for the well known (anonymous) memory mapped pages * - * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the + * Note that page->_mapcount is overloaded in SLAB/SLUB, so the * simple test in page_mapped() is not enough. */ if (!PageSlab(page) && page_mapped(page)) @@ -166,8 +166,7 @@ u64 stable_page_flags(struct page *page) /* * Caveats on high order pages: page->_refcount will only be set - * -1 on the head page; SLUB/SLQB do the same for PG_slab; - * SLOB won't set PG_slab at all on compound pages. + * -1 on the head page; SLAB/SLUB do the same for PG_slab; */ if (PageBuddy(page)) u |= 1 << KPF_BUDDY;
SLOB has been removed and SLQB never merged, so remove their mentions from comments and documentation of pagemap. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> --- Documentation/admin-guide/mm/pagemap.rst | 6 +++--- fs/proc/page.c | 5 ++--- 2 files changed, 5 insertions(+), 6 deletions(-)