On 2024/9/30 14:48, Baolin Wang wrote:
On 2024/9/30 11:15, Kefeng Wang wrote:
On 2024/9/30 10:52, Baolin Wang wrote:
On 2024/9/30 10:30, Kefeng Wang wrote:
On 2024/9/30 10:02, Baolin Wang wrote:
On 2024/9/26 21:52, Matthew Wilcox wrote:
On Thu, Sep 26, 2024 at 10:38:34AM +0200, Pankaj Raghav (Samsung)
wrote:
So this is why I don't use mapping_set_folio_order_range() here,
but
correct me if I am wrong.
Yeah, the inode is active here as the max folio size is decided
based on
the write size, so probably mapping_set_folio_order_range() will
not be
a safe option.
You really are all making too much of this. Here's the patch I
think we
need:
+++ b/mm/shmem.c
@@ -2831,7 +2831,8 @@ static struct inode
*__shmem_get_inode(struct mnt_idmap *idmap,
cache_no_acl(inode);
if (sbinfo->noswap)
mapping_set_unevictable(inode->i_mapping);
- mapping_set_large_folios(inode->i_mapping);
+ if (sbinfo->huge)
+ mapping_set_large_folios(inode->i_mapping);
switch (mode & S_IFMT) {
default:
IMHO, we no longer need the the 'sbinfo->huge' validation after
adding support for large folios in the tmpfs write and fallocate
paths [1].
Forget to mention, we still need to check sbinfo->huge, if mount with
huge=never, but we fault in large chunk, write is slower than without
9aac777aaf94, the above changes or my patch could fix it.
My patch will allow allocating large folios in the tmpfs write and
fallocate paths though the 'huge' option is 'never'.
Yes, indeed after checking your patch,
The Writing intelligently from 'Bonnie -d /mnt/tmpfs/ -s 1024' based on
next-20241008,
1) huge=never
the base: 2016438 K/Sec
my v1/v2 or Matthew's patch : 2874504 K/Sec
your patch with filemap_get_order() fix: 6330604 K/Sec
2) huge=always
the write performance: 7168917 K/Sec
Since large folios supported in the tmpfs write, we do have better
performance shown above, that's great.
My initial thought for supporting large folio is that, if the 'huge'
option is enabled, to maintain backward compatibility, we only allow 2M
PMD-sized order allocations. If the 'huge' option is
disabled(huge=never), we still allow large folio allocations based on
the write length.
Another choice is to allow the different sized large folio allocation
based on the write length when the 'huge' option is enabled, rather than
just the 2M PMD sized. But will force the huge orders off if 'huge'
option is disabled.
"huge=never Do not allocate huge pages. This is the default."
From the document, it's better not to allocate large folio, but we need
some special handle for huge=never or runtime deny/force.
Still need some discussions to determine which method is preferable.
Personally. I like your current implementation, but it does not match
document.
