| Message ID | 20210121014118.31922-1-rick.p.edgecombe@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/vmalloc: Separate put pages and flush VM flags | expand |
Hi: On 2021/1/21 9:41, Rick Edgecombe wrote: > When VM_MAP_PUT_PAGES was added, it was defined with the same value as > VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big Good catch! > functional problems other than some excess flushing for VM_MAP_PUT_PAGES > allocations. > > Redefine VM_MAP_PUT_PAGES to have its own value. Also, move the comment > and remove whitespace for VM_KASAN such that the flags lower down are less > likely to be missed in the future. >> Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap") Is this worth a Cc stable ? > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> > --- > include/linux/vmalloc.h | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > index 80c0181c411d..0b3dd135aa5d 100644 > --- a/include/linux/vmalloc.h > +++ b/include/linux/vmalloc.h > @@ -23,9 +23,6 @@ struct notifier_block; /* in notifier.h */ > #define VM_DMA_COHERENT 0x00000010 /* dma_alloc_coherent */ > #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */ > #define VM_NO_GUARD 0x00000040 /* don't add guard page */ > -#define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ > -#define VM_MAP_PUT_PAGES 0x00000100 /* put pages and free array in vfree */ > - > /* > * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC. > * > @@ -36,12 +33,13 @@ struct notifier_block; /* in notifier.h */ > * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to > * determine which allocations need the module shadow freed. > */ > - > +#define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ > /* > * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with > * vfree_atomic(). > */ > #define VM_FLUSH_RESET_PERMS 0x00000100 /* Reset direct map and flush TLB on unmap */ > +#define VM_MAP_PUT_PAGES 0x00000200 /* put pages and free array in vfree */ > > /* bits [20..32] reserved for arch specific ioremap internals */ > > Looks good to me. Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
On Wed, Jan 20, 2021 at 05:41:18PM -0800, Rick Edgecombe wrote: > When VM_MAP_PUT_PAGES was added, it was defined with the same value as > VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big > functional problems other than some excess flushing for VM_MAP_PUT_PAGES > allocations. > > Redefine VM_MAP_PUT_PAGES to have its own value. Also, move the comment > and remove whitespace for VM_KASAN such that the flags lower down are less > likely to be missed in the future. > > Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap") > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Ooops. Looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
On Wed, Jan 20, 2021 at 05:41:18PM -0800, Rick Edgecombe wrote: > When VM_MAP_PUT_PAGES was added, it was defined with the same value as > VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big > functional problems other than some excess flushing for VM_MAP_PUT_PAGES > allocations. > > Redefine VM_MAP_PUT_PAGES to have its own value. Also, move the comment > and remove whitespace for VM_KASAN such that the flags lower down are less > likely to be missed in the future. Er ... I think the problem was that VM_FLUSH_RESET_PERMS was put away from all the other flags! Why not this? diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 938eaf9517e26..458c41b99215e 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -24,7 +24,8 @@ struct notifier_block; /* in notifier.h */ #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */ #define VM_NO_GUARD 0x00000040 /* don't add guard page */ #define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ -#define VM_MAP_PUT_PAGES 0x00000100 /* put pages and free array in vfree */ +#define VM_FLUSH_RESET_PERMS 0x00000100 /* Reset direct map and flush TLB on unmap. cannot be freed in atomic context */ +#define VM_MAP_PUT_PAGES 0x00000200 /* put pages and free array in vfree */ /* * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC. @@ -37,12 +38,6 @@ struct notifier_block; /* in notifier.h */ * determine which allocations need the module shadow freed. */ -/* - * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with - * vfree_atomic(). - */ -#define VM_FLUSH_RESET_PERMS 0x00000100 /* Reset direct map and flush TLB on unmap */ - /* bits [20..32] reserved for arch specific ioremap internals */ /*
On Thu, 2021-01-21 at 13:19 +0000, Matthew Wilcox wrote: > On Wed, Jan 20, 2021 at 05:41:18PM -0800, Rick Edgecombe wrote: > > When VM_MAP_PUT_PAGES was added, it was defined with the same value > > as > > VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big > > functional problems other than some excess flushing for > > VM_MAP_PUT_PAGES > > allocations. > > > > Redefine VM_MAP_PUT_PAGES to have its own value. Also, move the > > comment > > and remove whitespace for VM_KASAN such that the flags lower down > > are less > > likely to be missed in the future. > > Er ... I think the problem was that VM_FLUSH_RESET_PERMS was put away > from > all the other flags! Well it wasn't that far away at the time, the VM_KASAN comment and whitespace got added later. But yes not ideal. > Why not this? 128 char line, but looks better to me.
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 80c0181c411d..0b3dd135aa5d 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -23,9 +23,6 @@ struct notifier_block; /* in notifier.h */ #define VM_DMA_COHERENT 0x00000010 /* dma_alloc_coherent */ #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */ #define VM_NO_GUARD 0x00000040 /* don't add guard page */ -#define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ -#define VM_MAP_PUT_PAGES 0x00000100 /* put pages and free array in vfree */ - /* * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC. * @@ -36,12 +33,13 @@ struct notifier_block; /* in notifier.h */ * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to * determine which allocations need the module shadow freed. */ - +#define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ /* * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with * vfree_atomic(). */ #define VM_FLUSH_RESET_PERMS 0x00000100 /* Reset direct map and flush TLB on unmap */ +#define VM_MAP_PUT_PAGES 0x00000200 /* put pages and free array in vfree */ /* bits [20..32] reserved for arch specific ioremap internals */
When VM_MAP_PUT_PAGES was added, it was defined with the same value as VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big functional problems other than some excess flushing for VM_MAP_PUT_PAGES allocations. Redefine VM_MAP_PUT_PAGES to have its own value. Also, move the comment and remove whitespace for VM_KASAN such that the flags lower down are less likely to be missed in the future. Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap") Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> --- include/linux/vmalloc.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)