From: Christoph Hellwig <hch@infradead.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Subject: Re: set_page_dirty variants
Date: Tue, 23 Mar 2021 15:41:25 +0000 [thread overview]
Message-ID: <20210323154125.GA2438080@infradead.org> (raw)
In-Reply-To: <20210322011907.GB1719932@casper.infradead.org>
On Mon, Mar 22, 2021 at 01:19:07AM +0000, Matthew Wilcox wrote:
> I'd like to get it down to zero. After all, the !mapping case in
> set_page_dirty() is exactly what we want. So is there a problem
> with doing this?
>
> +++ b/mm/page-writeback.c
> @@ -2562 +2562 @@ int set_page_dirty(struct page *page)
> - if (likely(mapping)) {
> + if (likely(mapping && mapping_can_writeback(mapping))) {
>
> But then I noticed that we have both mapping_can_writeback()
> and mapping_use_writeback_tags(), and I'm no longer sure
> which one to use. Also, why don't we mirror the results of
> inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK into
> a mapping->flags & AS_something bit?
Probably because no one has bothered to submit a patch yet.
next prev parent reply other threads:[~2021-03-23 15:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 1:19 set_page_dirty variants Matthew Wilcox
2021-03-23 15:41 ` Christoph Hellwig [this message]
2021-03-23 16:30 ` Matthew Wilcox
2021-03-23 16:35 ` Christoph Hellwig
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