Re: [PATCH 01/10] remove mapping from balance_dirty_pages*()
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2017-11-21 22:45:28
Also in:
linux-btrfs, linux-fsdevel
On Tue, 14 Nov 2017 16:56:47 -0500 Josef Bacik [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Josef Bacik <redacted> The only reason we pass in the mapping is to get the inode in order to see if writeback cgroups is enabled, and even then it only checks the bdi and a super block flag. balance_dirty_pages() doesn't even use the mapping. Since balance_dirty_pages*() works on a bdi level, just pass in the bdi and super block directly so we can avoid using mapping. This will allow us to still use balance_dirty_pages for dirty metadata pages that are not backed by an address_mapping. ...@@ -71,7 +72,8 @@ static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len) memset(page_address(page), 0xff, PAGE_SIZE); set_page_dirty(page); unlock_page(page); - balance_dirty_pages_ratelimited(mapping); + balance_dirty_pages_ratelimited(inode_to_bdi(inode), + inode->i_sb); break; }
So we do a bunch more work in each caller and we pass two args rather than one. That doesn't make things better! I see that this is enablement for "dirty metadata pages that are not backed by an address_mapping" (address_space) so I look into [7/10] and the changelog doesn't tell me much. So color me confused. What is this patchset actually *for*? Is there some filesystem which has non-address_space-backed metadata? Or will there be so soon? Or what. I think we need a [0/n] email please. One which fully describes the intent of the patchset. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>