From: Oleg Nesterov <oleg@redhat.com>
To: Song Liu <songliubraving@fb.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
matthew.wilcox@oracle.com, kirill.shutemov@linux.intel.com,
peterz@infradead.org, rostedt@goodmis.org, kernel-team@fb.com,
william.kucharski@oracle.com
Subject: Re: [PATCH v7 2/4] uprobe: use original page when all uprobes are removed
Date: Mon, 15 Jul 2019 17:25:14 +0200 [thread overview]
Message-ID: <20190715152513.GD1222@redhat.com> (raw)
In-Reply-To: <20190625235325.2096441-3-songliubraving@fb.com>
On 06/25, Song Liu wrote:
>
> This patch allows uprobe to use original page when possible (all uprobes
> on the page are already removed).
I can't review. I do not understand vm enough.
> + if (!is_register) {
> + struct page *orig_page;
> + pgoff_t index;
> +
> + index = vaddr_to_offset(vma, vaddr & PAGE_MASK) >> PAGE_SHIFT;
> + orig_page = find_get_page(vma->vm_file->f_inode->i_mapping,
> + index);
> +
> + if (orig_page) {
> + if (pages_identical(new_page, orig_page)) {
Shouldn't we at least check PageUptodate?
and I am a bit surprised there is no simple way to unmap the old page
in this case...
Oleg.
next prev parent reply other threads:[~2019-07-15 15:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 23:53 [PATCH v7 0/4] THP aware uprobe Song Liu
2019-06-25 23:53 ` [PATCH v7 1/4] mm: move memcmp_pages() and pages_identical() Song Liu
2019-06-25 23:53 ` [PATCH v7 2/4] uprobe: use original page when all uprobes are removed Song Liu
2019-06-26 6:00 ` Srikar Dronamraju
2019-07-15 15:25 ` Oleg Nesterov [this message]
2019-07-24 8:23 ` Song Liu
2019-07-24 8:57 ` Oleg Nesterov
2019-06-25 23:53 ` [PATCH v7 3/4] mm, thp: introduce FOLL_SPLIT_PMD Song Liu
2019-06-25 23:53 ` [PATCH v7 4/4] uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT Song Liu
2019-06-26 6:00 ` Srikar Dronamraju
2019-06-27 6:31 ` Song Liu
2019-06-26 0:03 ` [PATCH v7 0/4] THP aware uprobe Song Liu
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