Hi Lorenzo,
> > if (!rss_anon_before)
> > ksft_exit_fail_msg("No RssAnon is allocated before split\n");
> >
> > + /* Prevent khugepaged from collapsing the pages. */
> > + if (madvise(one_page, len, MADV_NOHUGEPAGE))
> > + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n");
>
> This should probably terminate the test no? There's no reason to expect this
> to
> fail and it's better to fail then to risk a flake :)
Okay. I thought it was rare, it seemed enough with just message.
I'll change with your suggesttion.
>
> > +
> > /* split all THPs */
> > write_debugfs(PID_FMT, getpid(), (uint64_t)one_page,
> > (uint64_t)one_page + len, 0);
> > @@ -227,6 +231,10 @@ static void split_pmd_thp_to_order(int order)
> > if (!check_huge_anon(one_page, 4 * pmd_pagesize, 4, pmd_pagesize))
> > ksft_exit_fail_msg("No THP is allocated\n");
> >
> > + /* Prevent khugepaged from collapsing the pages. */
> > + if (madvise(one_page, len, MADV_NOHUGEPAGE))
> > + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n");
> > +
>
> Same comment as above, also since this is a repeated pattern, I think it's
> worth
> abstracting it like:
>
> static void madv_nohuge(char *ptr, size_t len)
> {
> if (!madvise(ptr, len, MADV_NOHUGEPAGE))
> return;
>
> ksft_exit_fail_msg("MADV_NOHUGEPAGE failed, err=%d\n", errno);
> }
Acked.
>
> > /* split all THPs */
> > write_debugfs(PID_FMT, getpid(), (uint64_t)one_page,
> > (uint64_t)one_page + len, order);
> > @@ -313,6 +321,10 @@ static void split_pte_mapped_thp(void)
> > goto out;
> > }
> >
> > + /* Prevent khugepaged from collapsing the pages. */
> > + if (madvise(thp_area, thp_area_size, MADV_NOHUGEPAGE))
> > + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n");
> > +
> > /* Split all THPs through the remapped pages. */
> > write_debugfs(PID_FMT, getpid(), (uint64_t)page_area,
> > (uint64_t)page_area + page_area_size, 0);
> > @@ -542,6 +554,9 @@ static int create_pagecache_thp_and_fd(const char
> > *testfile, size_t fd_size,
> > ksft_test_result_skip("Pagecache folio split skipped\n");
> > return -2;
> > }
> > + /* Prevent khugepaged from collapsing the pages. */
> > + if (madvise(*addr, fd_size, MADV_NOHUGEPAGE))
> > + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n");
>
> Obviously same comments re: this and above
>
Thanks!
[...]
--
Sincerely,
Yeoreum Yun
