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Groups > linux.kernel > #1494004
| From | Christoph Hellwig <hch@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support |
| Date | 2016-09-30 12:00 +0200 |
| Message-ID | <sn2LM-8wm-3@gated-at.bofh.it> (permalink) |
| References | <smSjo-1SH-1@gated-at.bofh.it> <smSt4-1Wd-23@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
> -/*
> - * We use lowest available bit in exceptional entry for locking, other two
> - * bits to determine entry type. In total 3 special bits.
> - */
> -#define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 3)
> -#define RADIX_DAX_PTE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
> -#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
> -#define RADIX_DAX_TYPE_MASK (RADIX_DAX_PTE | RADIX_DAX_PMD)
> -#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK)
> -#define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT))
> -#define RADIX_DAX_ENTRY(sector, pmd) ((void *)((unsigned long)sector << \
> - RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE) | \
> - RADIX_TREE_EXCEPTIONAL_ENTRY))
> -
Please split the move of these constants into a separate patch.
> -static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index)
> +static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
> + unsigned long new_type)
> {
> + bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */
> void *entry, **slot;
>
> restart:
> spin_lock_irq(&mapping->tree_lock);
> entry = get_unlocked_mapping_entry(mapping, index, &slot);
> +
> + if (entry && new_type == RADIX_DAX_PMD) {
> + if (!radix_tree_exceptional_entry(entry) ||
> + RADIX_DAX_TYPE(entry) == RADIX_DAX_PTE) {
> + spin_unlock_irq(&mapping->tree_lock);
> + return ERR_PTR(-EEXIST);
> + }
> + } else if (entry && new_type == RADIX_DAX_PTE) {
> + if (radix_tree_exceptional_entry(entry) &&
> + RADIX_DAX_TYPE(entry) == RADIX_DAX_PMD &&
> + (unsigned long)entry & (RADIX_DAX_HZP|RADIX_DAX_EMPTY)) {
> + pmd_downgrade = true;
> + }
> + }
Would be nice to use switch on the type here:
old_type = RADIX_DAX_TYPE(entry);
if (entry) {
switch (new_type) {
case RADIX_DAX_PMD:
if (!radix_tree_exceptional_entry(entry) ||
oldentry == RADIX_DAX_PTE) {
entry = ERR_PTR(-EEXIST);
goto out_unlock;
}
break;
case RADIX_DAX_PTE:
if (radix_tree_exceptional_entry(entry) &&
old_entry = RADIX_DAX_PMD &&
(unsigned long)entry &
(RADIX_DAX_HZP|RADIX_DAX_EMPTY))
..
Btw, why are only RADIX_DAX_PTE and RADIX_DAX_PMD in the type mask,
and not RADIX_DAX_HZP and RADIX_DAX_EMPTY? With that we could use the
above old_entry local variable over this function and make it a lot les
of a mess.
> static void *dax_insert_mapping_entry(struct address_space *mapping,
> struct vm_fault *vmf,
> - void *entry, sector_t sector)
> + void *entry, sector_t sector,
> + unsigned long new_type, bool hzp)
And then we could also drop the hzp argument here..
> #ifdef CONFIG_FS_IOMAP
> +static inline sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
> +{
> + return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
> +}
Please split adding this new helper into a separate patch.
> +#if defined(CONFIG_FS_DAX_PMD)
Please use #ifdef here.
> +#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK)
> +#define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT))
> +
> +/* entries begin locked */
> +#define RADIX_DAX_ENTRY(sector, type) ((void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |\
> + type | (unsigned long)sector << RADIX_DAX_SHIFT | RADIX_DAX_ENTRY_LOCK))
> +#define RADIX_DAX_HZP_ENTRY() ((void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | \
> + RADIX_DAX_PMD | RADIX_DAX_HZP | RADIX_DAX_EMPTY | RADIX_DAX_ENTRY_LOCK))
> +#define RADIX_DAX_EMPTY_ENTRY(type) ((void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | \
> + type | RADIX_DAX_EMPTY | RADIX_DAX_ENTRY_LOCK))
> +
> +#define RADIX_DAX_ORDER(type) (type == RADIX_DAX_PMD ? PMD_SHIFT-PAGE_SHIFT : 0)
All these macros don't properly brace their arguments. I think
you'd make your life a lot easier by making them inline functions.
> +#if defined(CONFIG_FS_DAX_PMD)
#ifdef, please
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 00:50 +0200
[PATCH v4 06/12] dax: consistent variable naming for DAX entries Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 06/12] dax: consistent variable naming for DAX entries Jan Kara <jack@suse.cz> - 2016-10-03 11:40 +0200
[PATCH v4 02/12] ext4: tell DAX the size of allocation holes Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 05/12] dax: make 'wait_table' global variable static Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 05/12] dax: make 'wait_table' global variable static Jan Kara <jack@suse.cz> - 2016-10-03 11:40 +0200
[PATCH v4 12/12] dax: remove "depends on BROKEN" from FS_DAX_PMD Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 09/12] dax: correct dax iomap code namespace Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 09/12] dax: correct dax iomap code namespace Christoph Hellwig <hch@lst.de> - 2016-09-30 11:00 +0200
Re: [PATCH v4 09/12] dax: correct dax iomap code namespace Jan Kara <jack@suse.cz> - 2016-10-03 12:00 +0200
[PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Christoph Hellwig <hch@infradead.org> - 2016-09-30 11:50 +0200
Re: [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Jan Kara <jack@suse.cz> - 2016-10-03 12:00 +0200
Re: [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 20:50 +0200
[PATCH v4 01/12] ext4: allow DAX writeback for hole punch Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 04/12] ext2: remove support for DAX PMD faults Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 04/12] ext2: remove support for DAX PMD faults Jan Kara <jack@suse.cz> - 2016-10-03 11:40 +0200
[PATCH v4 03/12] dax: remove buffer_size_valid() Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 03/12] dax: remove buffer_size_valid() Christoph Hellwig <hch@lst.de> - 2016-09-30 10:50 +0200
[PATCH v4 11/12] xfs: use struct iomap based DAX PMD fault path Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Christoph Hellwig <hch@infradead.org> - 2016-09-30 12:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 23:20 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-03 13:10 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Christoph Hellwig <hch@lst.de> - 2016-10-03 18:40 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 23:10 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-04 08:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-04 17:40 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-05 08:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-06 23:40 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-07 05:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-07 09:50 +0200
[PATCH v4 08/12] dax: remove dax_pmd_fault() Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 08/12] dax: remove dax_pmd_fault() Jan Kara <jack@suse.cz> - 2016-10-03 12:00 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Dave Chinner <david@fromorbit.com> - 2016-09-30 01:50 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 05:10 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support "Darrick J. Wong" <darrick.wong@oracle.com> - 2016-09-30 06:10 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 21:00 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Dave Chinner <david@fromorbit.com> - 2016-09-30 08:50 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 23:20 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-04 01:10 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Christoph Hellwig <hch@infradead.org> - 2016-09-30 13:50 +0200
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