From: Matthew Wilcox <willy@infradead.org>
To: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <ak@linux.intel.com>, Christoph Lameter <cl@linux.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
David Hildenbrand <david@redhat.com>,
Suren Baghdasaryan <surenb@google.com>,
Yang Shi <shy828301@gmail.com>,
Sidhartha Kumar <sidhartha.kumar@oracle.com>,
Vishal Moola <vishal.moola@gmail.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Tejun Heo <tj@kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Michal Hocko <mhocko@suse.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 07/12] mempolicy: mpol_shared_policy_init() without pseudo-vma
Date: Mon, 25 Sep 2023 23:50:53 +0100 [thread overview]
Message-ID: <ZRIOzcI78x8BmGdo@casper.infradead.org> (raw)
In-Reply-To: <ea413d84-8b43-91c2-feef-92998bc7c1e2@google.com>
On Mon, Sep 25, 2023 at 01:29:28AM -0700, Hugh Dickins wrote:
> + /* alloc node covering entire file; adds ref to new */
This comment is confusing. sp_alloc initialises the refcount of 'n' to 1.
Which is the same memory referred to by the name 'new' in __mpol_dup(),
but in this function, the name "new" refers to the mempolicy called
"old" in __mpol_dup().
> + n = sp_alloc(0, MAX_LFS_FILESIZE >> PAGE_SHIFT, new);
> + if (n)
> + sp_insert(sp, n);
> put_new:
> mpol_put(new); /* drop initial ref */
> free_scratch:
This is all a bit inefficient, really. We call mpol_new() to get a
new mpol, then we set it up, then we dup it, then we free it. It'd
be nice if we could donate it instead of copying it. Maybe you'll
do something like that later.
next prev parent reply other threads:[~2023-09-25 22:51 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-25 8:17 [PATCH 00/12] mempolicy: cleanups leading to NUMA mpol without vma Hugh Dickins
2023-09-25 8:21 ` [PATCH 01/12] hugetlbfs: drop shared NUMA mempolicy pretence Hugh Dickins
2023-09-25 22:09 ` Matthew Wilcox
2023-09-25 22:46 ` Andi Kleen
2023-09-26 22:26 ` Hugh Dickins
2023-09-25 8:22 ` [PATCH 02/12] kernfs: drop shared NUMA mempolicy hooks Hugh Dickins
2023-09-25 22:10 ` Matthew Wilcox
2023-09-25 8:24 ` [PATCH 03/12] mempolicy: fix migrate_pages(2) syscall return nr_failed Hugh Dickins
2023-09-25 22:22 ` Matthew Wilcox
2023-09-26 20:47 ` Hugh Dickins
2023-09-27 8:02 ` Huang, Ying
2023-09-30 4:20 ` Hugh Dickins
2023-09-25 8:25 ` [PATCH 04/12] mempolicy trivia: delete those ancient pr_debug()s Hugh Dickins
2023-09-25 22:23 ` Matthew Wilcox
2023-09-25 8:26 ` [PATCH 05/12] mempolicy trivia: slightly more consistent naming Hugh Dickins
2023-09-25 22:28 ` Matthew Wilcox
2023-09-25 8:28 ` [PATCH 06/12] mempolicy trivia: use pgoff_t in shared mempolicy tree Hugh Dickins
2023-09-25 22:31 ` Matthew Wilcox
2023-09-25 22:38 ` Matthew Wilcox
2023-09-26 21:19 ` Hugh Dickins
2023-09-25 8:29 ` [PATCH 07/12] mempolicy: mpol_shared_policy_init() without pseudo-vma Hugh Dickins
2023-09-25 22:50 ` Matthew Wilcox [this message]
2023-09-26 21:36 ` Hugh Dickins
2023-09-25 8:30 ` [PATCH 08/12] mempolicy: remove confusing MPOL_MF_LAZY dead code Hugh Dickins
2023-09-25 22:52 ` Matthew Wilcox
2023-09-25 8:32 ` [PATCH 09/12] mm: add page_rmappable_folio() wrapper Hugh Dickins
2023-09-25 22:58 ` Matthew Wilcox
2023-09-26 21:58 ` Hugh Dickins
2023-09-25 8:33 ` [PATCH 10/12] mempolicy: alloc_pages_mpol() for NUMA policy without vma Hugh Dickins
2023-09-25 8:35 ` [PATCH 11/12] mempolicy: mmap_lock is not needed while migrating folios Hugh Dickins
2023-09-25 8:36 ` [PATCH 12/12] mempolicy: migration attempt to match interleave nodes Hugh Dickins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZRIOzcI78x8BmGdo@casper.infradead.org \
--to=willy@infradead.org \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=david@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=shy828301@gmail.com \
--cc=sidhartha.kumar@oracle.com \
--cc=surenb@google.com \
--cc=tj@kernel.org \
--cc=vishal.moola@gmail.com \
--cc=wangkefeng.wang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).