| Message ID | eabd8c89fc1b4807eaf28750e04c44b718ae6487.1731397290.git.baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Support large folios for tmpfs | expand |
On 12.11.24 08:45, Baolin Wang wrote: > Add large folio support for tmpfs write and fallocate paths matching the > same high order preference mechanism used in the iomap buffered IO path > as used in __filemap_get_folio(). > > Add shmem_mapping_size_orders() to get a hint for the orders of the folio > based on the file size which takes care of the mapping requirements. > > Traditionally, tmpfs only supported PMD-sized huge folios. However nowadays > with other file systems supporting any sized large folios, and extending > anonymous to support mTHP, we should not restrict tmpfs to allocating only > PMD-sized huge folios, making it more special. Instead, we should allow > tmpfs can allocate any sized large folios. > > Considering that tmpfs already has the 'huge=' option to control the huge > folios allocation, we can extend the 'huge=' option to allow any sized huge > folios. The semantics of the 'huge=' mount option are: > > huge=never: no any sized huge folios > huge=always: any sized huge folios > huge=within_size: like 'always' but respect the i_size > huge=advise: like 'always' if requested with fadvise()/madvise() > > Note: for tmpfs mmap() faults, due to the lack of a write size hint, still > allocate the PMD-sized huge folios if huge=always/within_size/advise is set. > > Moreover, the 'deny' and 'force' testing options controlled by > '/sys/kernel/mm/transparent_hugepage/shmem_enabled', still retain the same > semantics. The 'deny' can disable any sized large folios for tmpfs, while > the 'force' can enable PMD sized large folios for tmpfs. > > Co-developed-by: Daniel Gomez <da.gomez@samsung.com> > Signed-off-by: Daniel Gomez <da.gomez@samsung.com> > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > --- > mm/shmem.c | 91 +++++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 77 insertions(+), 14 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 86b2e417dc6f..a3203cf8860f 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -549,10 +549,50 @@ static bool shmem_confirm_swap(struct address_space *mapping, > > static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER; > > +/** > + * shmem_mapping_size_orders - Get allowable folio orders for the given file size. > + * @mapping: Target address_space. > + * @index: The page index. > + * @write_end: end of a write, could extend inode size. > + * > + * This returns huge orders for folios (when supported) based on the file size > + * which the mapping currently allows at the given index. The index is relevant > + * due to alignment considerations the mapping might have. The returned order > + * may be less than the size passed. > + * > + * Return: The orders. > + */ > +static inline unsigned int > +shmem_mapping_size_orders(struct address_space *mapping, pgoff_t index, loff_t write_end) > +{ > + unsigned int order; > + size_t size; > + > + if (!mapping_large_folio_support(mapping) || !write_end) > + return 0; > + > + /* Calculate the write size based on the write_end */ > + size = write_end - (index << PAGE_SHIFT); > + order = filemap_get_order(size); > + if (!order) > + return 0; > + > + /* If we're not aligned, allocate a smaller folio */ > + if (index & ((1UL << order) - 1)) > + order = __ffs(index); > + > + order = min_t(size_t, order, MAX_PAGECACHE_ORDER); > + return order > 0 ? BIT(order + 1) - 1 : 0; > +} > + > static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index, > loff_t write_end, bool shmem_huge_force, > + struct vm_area_struct *vma, > unsigned long vm_flags) > { > + unsigned long within_size_orders; > + unsigned int order; > + pgoff_t aligned_index; > loff_t i_size; > > if (HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER) We can allow all orders up to MAX_PAGECACHE_ORDER, shmem_mapping_size_orders() handles it properly. So maybe we should drop this condition and use instead below where we have return BIT(HPAGE_PMD_ORDER); instead something like. return HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ? 0 : BIT(HPAGE_PMD_ORDER); Ideally, factoring it out somehow int maybe_pmd_order = HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ? 0 : BIT(HPAGE_PMD_ORDER); ... return maybe_pmd_order; > @@ -564,15 +604,41 @@ static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index > if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE) > return BIT(HPAGE_PMD_ORDER); Why not force-enable all orders (of course, respecting MAX_PAGECACHE_ORDER and possibly VMA)? > > + /* > + * The huge order allocation for anon shmem is controlled through > + * the mTHP interface, so we still use PMD-sized huge order to > + * check whether global control is enabled. > + * > + * For tmpfs mmap()'s huge order, we still use PMD-sized order to > + * allocate huge pages due to lack of a write size hint. > + * > + * Otherwise, tmpfs will allow getting a highest order hint based on > + * the size of write and fallocate paths, then will try each allowable > + * huge orders. > + */ > switch (SHMEM_SB(inode->i_sb)->huge) { > case SHMEM_HUGE_ALWAYS: > - return BIT(HPAGE_PMD_ORDER); > - case SHMEM_HUGE_WITHIN_SIZE: > - index = round_up(index + 1, HPAGE_PMD_NR); > - i_size = max(write_end, i_size_read(inode)); > - i_size = round_up(i_size, PAGE_SIZE); > - if (i_size >> PAGE_SHIFT >= index) > + if (vma) > return BIT(HPAGE_PMD_ORDER); > + > + return shmem_mapping_size_orders(inode->i_mapping, index, write_end); > + case SHMEM_HUGE_WITHIN_SIZE: > + if (vma) > + within_size_orders = BIT(HPAGE_PMD_ORDER); > + else > + within_size_orders = shmem_mapping_size_orders(inode->i_mapping, > + index, write_end); > + > + order = highest_order(within_size_orders); > + while (within_size_orders) { > + aligned_index = round_up(index + 1, 1 << order); > + i_size = max(write_end, i_size_read(inode)); > + i_size = round_up(i_size, PAGE_SIZE); > + if (i_size >> PAGE_SHIFT >= aligned_index) > + return within_size_orders; > + > + order = next_order(&within_size_orders, order); > + } > fallthrough; > case SHMEM_HUGE_ADVISE: > if (vm_flags & VM_HUGEPAGE) I think the point here is that "write" -> no VMA -> vm_flags == 0 -> no code changes needed :)
On 12.11.24 17:19, David Hildenbrand wrote: > On 12.11.24 08:45, Baolin Wang wrote: >> Add large folio support for tmpfs write and fallocate paths matching the >> same high order preference mechanism used in the iomap buffered IO path >> as used in __filemap_get_folio(). >> >> Add shmem_mapping_size_orders() to get a hint for the orders of the folio >> based on the file size which takes care of the mapping requirements. >> >> Traditionally, tmpfs only supported PMD-sized huge folios. However nowadays >> with other file systems supporting any sized large folios, and extending >> anonymous to support mTHP, we should not restrict tmpfs to allocating only >> PMD-sized huge folios, making it more special. Instead, we should allow >> tmpfs can allocate any sized large folios. >> >> Considering that tmpfs already has the 'huge=' option to control the huge >> folios allocation, we can extend the 'huge=' option to allow any sized huge >> folios. The semantics of the 'huge=' mount option are: >> >> huge=never: no any sized huge folios >> huge=always: any sized huge folios >> huge=within_size: like 'always' but respect the i_size >> huge=advise: like 'always' if requested with fadvise()/madvise() >> >> Note: for tmpfs mmap() faults, due to the lack of a write size hint, still >> allocate the PMD-sized huge folios if huge=always/within_size/advise is set. >> >> Moreover, the 'deny' and 'force' testing options controlled by >> '/sys/kernel/mm/transparent_hugepage/shmem_enabled', still retain the same >> semantics. The 'deny' can disable any sized large folios for tmpfs, while >> the 'force' can enable PMD sized large folios for tmpfs. >> >> Co-developed-by: Daniel Gomez <da.gomez@samsung.com> >> Signed-off-by: Daniel Gomez <da.gomez@samsung.com> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> --- >> mm/shmem.c | 91 +++++++++++++++++++++++++++++++++++++++++++++--------- >> 1 file changed, 77 insertions(+), 14 deletions(-) >> >> diff --git a/mm/shmem.c b/mm/shmem.c >> index 86b2e417dc6f..a3203cf8860f 100644 >> --- a/mm/shmem.c >> +++ b/mm/shmem.c >> @@ -549,10 +549,50 @@ static bool shmem_confirm_swap(struct address_space *mapping, >> >> static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER; >> >> +/** >> + * shmem_mapping_size_orders - Get allowable folio orders for the given file size. >> + * @mapping: Target address_space. >> + * @index: The page index. >> + * @write_end: end of a write, could extend inode size. >> + * >> + * This returns huge orders for folios (when supported) based on the file size >> + * which the mapping currently allows at the given index. The index is relevant >> + * due to alignment considerations the mapping might have. The returned order >> + * may be less than the size passed. >> + * >> + * Return: The orders. >> + */ >> +static inline unsigned int >> +shmem_mapping_size_orders(struct address_space *mapping, pgoff_t index, loff_t write_end) >> +{ >> + unsigned int order; >> + size_t size; >> + >> + if (!mapping_large_folio_support(mapping) || !write_end) >> + return 0; >> + >> + /* Calculate the write size based on the write_end */ >> + size = write_end - (index << PAGE_SHIFT); >> + order = filemap_get_order(size); >> + if (!order) >> + return 0; >> + >> + /* If we're not aligned, allocate a smaller folio */ >> + if (index & ((1UL << order) - 1)) >> + order = __ffs(index); >> + >> + order = min_t(size_t, order, MAX_PAGECACHE_ORDER); >> + return order > 0 ? BIT(order + 1) - 1 : 0; >> +} >> + >> static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index, >> loff_t write_end, bool shmem_huge_force, >> + struct vm_area_struct *vma, >> unsigned long vm_flags) >> { >> + unsigned long within_size_orders; >> + unsigned int order; >> + pgoff_t aligned_index; >> loff_t i_size; >> >> if (HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER) > > We can allow all orders up to MAX_PAGECACHE_ORDER, > shmem_mapping_size_orders() handles it properly. > > So maybe we should drop this condition and use instead below where we have > > return BIT(HPAGE_PMD_ORDER); > > instead something like. > > return HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ? 0 : BIT(HPAGE_PMD_ORDER); > > Ideally, factoring it out somehow > > > int maybe_pmd_order = HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ? 0 : > BIT(HPAGE_PMD_ORDER); > > ... > > return maybe_pmd_order; > >> @@ -564,15 +604,41 @@ static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index >> if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE) >> return BIT(HPAGE_PMD_ORDER); > > Why not force-enable all orders (of course, respecting > MAX_PAGECACHE_ORDER and possibly VMA)? > >> >> + /* >> + * The huge order allocation for anon shmem is controlled through >> + * the mTHP interface, so we still use PMD-sized huge order to >> + * check whether global control is enabled. >> + * >> + * For tmpfs mmap()'s huge order, we still use PMD-sized order to >> + * allocate huge pages due to lack of a write size hint. >> + * >> + * Otherwise, tmpfs will allow getting a highest order hint based on >> + * the size of write and fallocate paths, then will try each allowable >> + * huge orders. >> + */ >> switch (SHMEM_SB(inode->i_sb)->huge) { >> case SHMEM_HUGE_ALWAYS: >> - return BIT(HPAGE_PMD_ORDER); >> - case SHMEM_HUGE_WITHIN_SIZE: >> - index = round_up(index + 1, HPAGE_PMD_NR); >> - i_size = max(write_end, i_size_read(inode)); >> - i_size = round_up(i_size, PAGE_SIZE); >> - if (i_size >> PAGE_SHIFT >= index) >> + if (vma) >> return BIT(HPAGE_PMD_ORDER); >> + >> + return shmem_mapping_size_orders(inode->i_mapping, index, write_end); >> + case SHMEM_HUGE_WITHIN_SIZE: >> + if (vma) >> + within_size_orders = BIT(HPAGE_PMD_ORDER); >> + else >> + within_size_orders = shmem_mapping_size_orders(inode->i_mapping, >> + index, write_end); >> + >> + order = highest_order(within_size_orders); >> + while (within_size_orders) { >> + aligned_index = round_up(index + 1, 1 << order); >> + i_size = max(write_end, i_size_read(inode)); >> + i_size = round_up(i_size, PAGE_SIZE); >> + if (i_size >> PAGE_SHIFT >= aligned_index) >> + return within_size_orders; >> + >> + order = next_order(&within_size_orders, order); >> + } >> fallthrough; >> case SHMEM_HUGE_ADVISE: >> if (vm_flags & VM_HUGEPAGE) > > I think the point here is that "write" -> no VMA -> vm_flags == 0 -> no > code changes needed :) ... and now I wonder about documented "fadvise", because this here is only concerned with madvise?
On 2024/11/13 00:19, David Hildenbrand wrote: > On 12.11.24 08:45, Baolin Wang wrote: >> Add large folio support for tmpfs write and fallocate paths matching the >> same high order preference mechanism used in the iomap buffered IO path >> as used in __filemap_get_folio(). >> >> Add shmem_mapping_size_orders() to get a hint for the orders of the folio >> based on the file size which takes care of the mapping requirements. >> >> Traditionally, tmpfs only supported PMD-sized huge folios. However >> nowadays >> with other file systems supporting any sized large folios, and extending >> anonymous to support mTHP, we should not restrict tmpfs to allocating >> only >> PMD-sized huge folios, making it more special. Instead, we should allow >> tmpfs can allocate any sized large folios. >> >> Considering that tmpfs already has the 'huge=' option to control the huge >> folios allocation, we can extend the 'huge=' option to allow any sized >> huge >> folios. The semantics of the 'huge=' mount option are: >> >> huge=never: no any sized huge folios >> huge=always: any sized huge folios >> huge=within_size: like 'always' but respect the i_size >> huge=advise: like 'always' if requested with fadvise()/madvise() >> >> Note: for tmpfs mmap() faults, due to the lack of a write size hint, >> still >> allocate the PMD-sized huge folios if huge=always/within_size/advise >> is set. >> >> Moreover, the 'deny' and 'force' testing options controlled by >> '/sys/kernel/mm/transparent_hugepage/shmem_enabled', still retain the >> same >> semantics. The 'deny' can disable any sized large folios for tmpfs, while >> the 'force' can enable PMD sized large folios for tmpfs. >> >> Co-developed-by: Daniel Gomez <da.gomez@samsung.com> >> Signed-off-by: Daniel Gomez <da.gomez@samsung.com> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> --- >> mm/shmem.c | 91 +++++++++++++++++++++++++++++++++++++++++++++--------- >> 1 file changed, 77 insertions(+), 14 deletions(-) >> >> diff --git a/mm/shmem.c b/mm/shmem.c >> index 86b2e417dc6f..a3203cf8860f 100644 >> --- a/mm/shmem.c >> +++ b/mm/shmem.c >> @@ -549,10 +549,50 @@ static bool shmem_confirm_swap(struct >> address_space *mapping, >> static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER; >> +/** >> + * shmem_mapping_size_orders - Get allowable folio orders for the >> given file size. >> + * @mapping: Target address_space. >> + * @index: The page index. >> + * @write_end: end of a write, could extend inode size. >> + * >> + * This returns huge orders for folios (when supported) based on the >> file size >> + * which the mapping currently allows at the given index. The index >> is relevant >> + * due to alignment considerations the mapping might have. The >> returned order >> + * may be less than the size passed. >> + * >> + * Return: The orders. >> + */ >> +static inline unsigned int >> +shmem_mapping_size_orders(struct address_space *mapping, pgoff_t >> index, loff_t write_end) >> +{ >> + unsigned int order; >> + size_t size; >> + >> + if (!mapping_large_folio_support(mapping) || !write_end) >> + return 0; >> + >> + /* Calculate the write size based on the write_end */ >> + size = write_end - (index << PAGE_SHIFT); >> + order = filemap_get_order(size); >> + if (!order) >> + return 0; >> + >> + /* If we're not aligned, allocate a smaller folio */ >> + if (index & ((1UL << order) - 1)) >> + order = __ffs(index); >> + >> + order = min_t(size_t, order, MAX_PAGECACHE_ORDER); >> + return order > 0 ? BIT(order + 1) - 1 : 0; >> +} >> + >> static unsigned int shmem_huge_global_enabled(struct inode *inode, >> pgoff_t index, >> loff_t write_end, bool shmem_huge_force, >> + struct vm_area_struct *vma, >> unsigned long vm_flags) >> { >> + unsigned long within_size_orders; >> + unsigned int order; >> + pgoff_t aligned_index; >> loff_t i_size; >> if (HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER) > > We can allow all orders up to MAX_PAGECACHE_ORDER, > shmem_mapping_size_orders() handles it properly. > > So maybe we should drop this condition and use instead below where we have > > return BIT(HPAGE_PMD_ORDER); > > instead something like. > > return HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ? 0 : BIT(HPAGE_PMD_ORDER); > > Ideally, factoring it out somehow > > > int maybe_pmd_order = HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ? 0 : > BIT(HPAGE_PMD_ORDER); > > ... > > return maybe_pmd_order; Good point. Will do. > >> @@ -564,15 +604,41 @@ static unsigned int >> shmem_huge_global_enabled(struct inode *inode, pgoff_t index >> if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE) >> return BIT(HPAGE_PMD_ORDER); > > Why not force-enable all orders (of course, respecting > MAX_PAGECACHE_ORDER and possibly VMA)? The ‘force’ option will affect the tmpfs mmap()'s huge allocation, which I intend to handle in a separate patch as we discussed. Additionally, for the huge page allocation of tmpfs mmap(), I am also considering the readahead approach for the pagecache. >> + /* >> + * The huge order allocation for anon shmem is controlled through >> + * the mTHP interface, so we still use PMD-sized huge order to >> + * check whether global control is enabled. >> + * >> + * For tmpfs mmap()'s huge order, we still use PMD-sized order to >> + * allocate huge pages due to lack of a write size hint. >> + * >> + * Otherwise, tmpfs will allow getting a highest order hint based on >> + * the size of write and fallocate paths, then will try each >> allowable >> + * huge orders. >> + */ >> switch (SHMEM_SB(inode->i_sb)->huge) { >> case SHMEM_HUGE_ALWAYS: >> - return BIT(HPAGE_PMD_ORDER); >> - case SHMEM_HUGE_WITHIN_SIZE: >> - index = round_up(index + 1, HPAGE_PMD_NR); >> - i_size = max(write_end, i_size_read(inode)); >> - i_size = round_up(i_size, PAGE_SIZE); >> - if (i_size >> PAGE_SHIFT >= index) >> + if (vma) >> return BIT(HPAGE_PMD_ORDER); >> + >> + return shmem_mapping_size_orders(inode->i_mapping, index, >> write_end); >> + case SHMEM_HUGE_WITHIN_SIZE: >> + if (vma) >> + within_size_orders = BIT(HPAGE_PMD_ORDER); >> + else >> + within_size_orders = >> shmem_mapping_size_orders(inode->i_mapping, >> + index, write_end); >> + >> + order = highest_order(within_size_orders); >> + while (within_size_orders) { >> + aligned_index = round_up(index + 1, 1 << order); >> + i_size = max(write_end, i_size_read(inode)); >> + i_size = round_up(i_size, PAGE_SIZE); >> + if (i_size >> PAGE_SHIFT >= aligned_index) >> + return within_size_orders; >> + >> + order = next_order(&within_size_orders, order); >> + } >> fallthrough; >> case SHMEM_HUGE_ADVISE: >> if (vm_flags & VM_HUGEPAGE) > > I think the point here is that "write" -> no VMA -> vm_flags == 0 -> no > code changes needed :) Yes. Currently the fadvise() have no HUGEPAGE handling, so I will drop the 'fadvise' in the doc.
>>> return BIT(HPAGE_PMD_ORDER); >> >> Why not force-enable all orders (of course, respecting >> MAX_PAGECACHE_ORDER and possibly VMA)? > > The ‘force’ option will affect the tmpfs mmap()'s huge allocation, which > I intend to handle in a separate patch as we discussed. Additionally, > for the huge page allocation of tmpfs mmap(), I am also considering the > readahead approach for the pagecache. Okay, we can change this later. Likely force/deny are a blast from the past either way. [...] >>> + >>> + order = highest_order(within_size_orders); >>> + while (within_size_orders) { >>> + aligned_index = round_up(index + 1, 1 << order); >>> + i_size = max(write_end, i_size_read(inode)); >>> + i_size = round_up(i_size, PAGE_SIZE); >>> + if (i_size >> PAGE_SHIFT >= aligned_index) >>> + return within_size_orders; >>> + >>> + order = next_order(&within_size_orders, order); >>> + } >>> fallthrough; >>> case SHMEM_HUGE_ADVISE: >>> if (vm_flags & VM_HUGEPAGE) >> >> I think the point here is that "write" -> no VMA -> vm_flags == 0 -> no >> code changes needed :) > > Yes. Currently the fadvise() have no HUGEPAGE handling, so I will drop > the 'fadvise' in the doc. Interesting that we documented it :)
diff --git a/mm/shmem.c b/mm/shmem.c index 86b2e417dc6f..a3203cf8860f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -549,10 +549,50 @@ static bool shmem_confirm_swap(struct address_space *mapping, static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER; +/** + * shmem_mapping_size_orders - Get allowable folio orders for the given file size. + * @mapping: Target address_space. + * @index: The page index. + * @write_end: end of a write, could extend inode size. + * + * This returns huge orders for folios (when supported) based on the file size + * which the mapping currently allows at the given index. The index is relevant + * due to alignment considerations the mapping might have. The returned order + * may be less than the size passed. + * + * Return: The orders. + */ +static inline unsigned int +shmem_mapping_size_orders(struct address_space *mapping, pgoff_t index, loff_t write_end) +{ + unsigned int order; + size_t size; + + if (!mapping_large_folio_support(mapping) || !write_end) + return 0; + + /* Calculate the write size based on the write_end */ + size = write_end - (index << PAGE_SHIFT); + order = filemap_get_order(size); + if (!order) + return 0; + + /* If we're not aligned, allocate a smaller folio */ + if (index & ((1UL << order) - 1)) + order = __ffs(index); + + order = min_t(size_t, order, MAX_PAGECACHE_ORDER); + return order > 0 ? BIT(order + 1) - 1 : 0; +} + static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index, loff_t write_end, bool shmem_huge_force, + struct vm_area_struct *vma, unsigned long vm_flags) { + unsigned long within_size_orders; + unsigned int order; + pgoff_t aligned_index; loff_t i_size; if (HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER) @@ -564,15 +604,41 @@ static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE) return BIT(HPAGE_PMD_ORDER); + /* + * The huge order allocation for anon shmem is controlled through + * the mTHP interface, so we still use PMD-sized huge order to + * check whether global control is enabled. + * + * For tmpfs mmap()'s huge order, we still use PMD-sized order to + * allocate huge pages due to lack of a write size hint. + * + * Otherwise, tmpfs will allow getting a highest order hint based on + * the size of write and fallocate paths, then will try each allowable + * huge orders. + */ switch (SHMEM_SB(inode->i_sb)->huge) { case SHMEM_HUGE_ALWAYS: - return BIT(HPAGE_PMD_ORDER); - case SHMEM_HUGE_WITHIN_SIZE: - index = round_up(index + 1, HPAGE_PMD_NR); - i_size = max(write_end, i_size_read(inode)); - i_size = round_up(i_size, PAGE_SIZE); - if (i_size >> PAGE_SHIFT >= index) + if (vma) return BIT(HPAGE_PMD_ORDER); + + return shmem_mapping_size_orders(inode->i_mapping, index, write_end); + case SHMEM_HUGE_WITHIN_SIZE: + if (vma) + within_size_orders = BIT(HPAGE_PMD_ORDER); + else + within_size_orders = shmem_mapping_size_orders(inode->i_mapping, + index, write_end); + + order = highest_order(within_size_orders); + while (within_size_orders) { + aligned_index = round_up(index + 1, 1 << order); + i_size = max(write_end, i_size_read(inode)); + i_size = round_up(i_size, PAGE_SIZE); + if (i_size >> PAGE_SHIFT >= aligned_index) + return within_size_orders; + + order = next_order(&within_size_orders, order); + } fallthrough; case SHMEM_HUGE_ADVISE: if (vm_flags & VM_HUGEPAGE) @@ -776,6 +842,7 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index, loff_t write_end, bool shmem_huge_force, + struct vm_area_struct *vma, unsigned long vm_flags) { return 0; @@ -1173,7 +1240,7 @@ static int shmem_getattr(struct mnt_idmap *idmap, generic_fillattr(idmap, request_mask, inode, stat); inode_unlock_shared(inode); - if (shmem_huge_global_enabled(inode, 0, 0, false, 0)) + if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0)) stat->blksize = HPAGE_PMD_SIZE; if (request_mask & STATX_BTIME) { @@ -1690,14 +1757,10 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode, return 0; global_orders = shmem_huge_global_enabled(inode, index, write_end, - shmem_huge_force, vm_flags); - if (!vma || !vma_is_anon_shmem(vma)) { - /* - * For tmpfs, we now only support PMD sized THP if huge page - * is enabled, otherwise fallback to order 0. - */ + shmem_huge_force, vma, vm_flags); + /* Tmpfs huge pages allocation */ + if (!vma || !vma_is_anon_shmem(vma)) return global_orders; - } /* * Following the 'deny' semantics of the top level, force the huge