| Message ID | 20220116121822.1727633-10-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Enabling large folios for 5.17 | expand |
On 1/16/22 8:18 PM, Matthew Wilcox (Oracle) wrote: > From: William Kucharski <william.kucharski@oracle.com> > > When we have the opportunity to use PMDs to map a file, we want to follow > the same rules as DAX. > > Signed-off-by: William Kucharski <william.kucharski@oracle.com> > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > mm/huge_memory.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index f58524394dc1..28c29a0d854b 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -582,13 +582,10 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, > unsigned long ret; > loff_t off = (loff_t)pgoff << PAGE_SHIFT; > > - if (!IS_DAX(filp->f_mapping->host) || !IS_ENABLED(CONFIG_FS_DAX_PMD)) > - goto out; > - > ret = __thp_get_unmapped_area(filp, addr, len, off, flags, PMD_SIZE); > if (ret) > return ret; > -out: > + > return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); Hi, Matthew It seems this patch will make all file mappings align with PMD_SIZE? And support realize all file THP, not only executable file THP? Actually, what I want to say is we had merged a similar patch to only align DSO mapping in glibc: "718fdd8 elf: Properly align PT_LOAD segments [BZ #28676]" > } > EXPORT_SYMBOL_GPL(thp_get_unmapped_area);
On Mon, Jan 17, 2022 at 11:17:55AM +0800, Rongwei Wang wrote: > It seems this patch will make all file mappings align with PMD_SIZE? Only those which are big enough. See __thp_get_unmapped_area(): if (off_end <= off_align || (off_end - off_align) < size) return 0; > And > support realize all file THP, not only executable file THP? Executables are not the only files which benefit from being mapped to an aligned address. If you can use a PMD to map a font file, for example, that's valuable.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f58524394dc1..28c29a0d854b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -582,13 +582,10 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long ret; loff_t off = (loff_t)pgoff << PAGE_SHIFT; - if (!IS_DAX(filp->f_mapping->host) || !IS_ENABLED(CONFIG_FS_DAX_PMD)) - goto out; - ret = __thp_get_unmapped_area(filp, addr, len, off, flags, PMD_SIZE); if (ret) return ret; -out: + return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); } EXPORT_SYMBOL_GPL(thp_get_unmapped_area);