On Fri, Jan 26, 2024 at 05:28:58PM +0800, Zhaoyang Huang wrote:
> On Fri, Jan 26, 2024 at 4:55 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> >
> > On Fri, Jan 26, 2024 at 03:59:48PM +0800, Zhaoyang Huang wrote:
> > > loop more mm and fs guys for more comments
> >
> > I agree with everything Damien said. But also ...
> ok, I will find a way to solve this problem.
> >
> > > > +bool BIO_ADD_FOLIO(struct bio *bio, struct folio *folio, size_t len,
> > > > + size_t off)
> >
> > You don't add any users of these functions. It's hard to assess whether
> > this is the right API when there are no example users.
> Actually, the code has been tested on ext4 and f2fs by patchv2 on a
> v6.6 6GB android system where I get the test result posted on the
> commit message. These APIs is to keep block layer clean and wrap
> things up for fs.
well, where's patch v2? i don't see it in my inbox. i'm not going
to go hunting around the email lists for it. this is not good enough.
> > why are BIO_ADD_PAGE and BIO_ADD_FOLIO so very different from each
> > other?
> These two API just repeat the same thing that bio_add_page and
> bio_add_folio do.
what?
here's the patch you sent. these two functions do wildly different
things:
+bool BIO_ADD_FOLIO(struct bio *bio, struct folio *folio, size_t len,
+ size_t off)
+{
+ int class, level, hint, activity;
+
+ if (len > UINT_MAX || off > UINT_MAX)
+ return false;
+
+ class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
+ level = IOPRIO_PRIO_LEVEL(bio->bi_ioprio);
+ hint = IOPRIO_PRIO_HINT(bio->bi_ioprio);
+ activity = IOPRIO_PRIO_ACTIVITY(bio->bi_ioprio);
+
+ activity += (bio->bi_vcnt + 1 <= IOPRIO_NR_ACTIVITY &&
+ PageWorkingset(&folio->page)) ? 1 : 0;
+ if (activity >= bio->bi_vcnt / 2)
+ class = IOPRIO_CLASS_RT;
+ else if (activity >= bio->bi_vcnt / 4)
+ class = max(IOPRIO_PRIO_CLASS(get_current_ioprio()), IOPRIO_CLASS_BE);
+
+ bio->bi_ioprio = IOPRIO_PRIO_VALUE_ACTIVITY(class, level, hint, activity);
+
+ return bio_add_page(bio, &folio->page, len, off) > 0;
+}
+
+int BIO_ADD_PAGE(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
+{
+ int class, level, hint, activity;
+
+ if (bio_add_page(bio, page, len, offset) > 0) {
+ class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
+ level = IOPRIO_PRIO_LEVEL(bio->bi_ioprio);
+ hint = IOPRIO_PRIO_HINT(bio->bi_ioprio);
+ activity = IOPRIO_PRIO_ACTIVITY(bio->bi_ioprio);
+ activity += (bio->bi_vcnt <= IOPRIO_NR_ACTIVITY && PageWorkingset(page)) ? 1 : 0;
+ bio->bi_ioprio = IOPRIO_PRIO_VALUE_ACTIVITY(class, level, hint, activity);
+ }
+
+ return len;
+}
did you change one and forget to change the other?
> These white spaces are trimmed by vim, I will change them back in next version.
vim doesn't do that by default.
