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'.
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.
Still need some discussions to determine which method is preferable.
