From: Andrew Morton <akpm@linux-foundation.org>
To: Miaohe Lin <linmiaohe@huawei.com>
Cc: <willy@infradead.org>, <vbabka@suse.cz>, <dhowells@redhat.com>,
<neilb@suse.de>, <apopple@nvidia.com>, <david@redhat.com>,
<surenb@google.com>, <peterx@redhat.com>,
<naoya.horiguchi@nec.com>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 10/15] mm/swap: break the loop if matching device is found
Date: Mon, 9 May 2022 14:16:02 -0700 [thread overview]
Message-ID: <20220509141602.b6be120b80d0ab3218fe619a@linux-foundation.org> (raw)
In-Reply-To: <20220509131416.17553-11-linmiaohe@huawei.com>
On Mon, 9 May 2022 21:14:11 +0800 Miaohe Lin <linmiaohe@huawei.com> wrote:
> We can break the loop if matching device is found to save some possible
> cpu cycles because there should be only one matching device and there is
> no need to continue if the matching one is already found.
>
> ...
>
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1692,6 +1692,8 @@ int swap_type_of(dev_t device, sector_t offset)
> spin_unlock(&swap_lock);
> return type;
> }
> +
> + break;
> }
> }
> spin_unlock(&swap_lock);
Are you sure? If we have two S_ISREG swapfiles on the same device,
don't they have the same sis->bdev?
If not, why bother passing `offset' into this function at all?
next prev parent reply other threads:[~2022-05-09 21:16 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-09 13:14 [PATCH 00/15] A few cleanup patches for swap Miaohe Lin
2022-05-09 13:14 ` [PATCH 01/15] mm/swap: use helper is_swap_pte() in swap_vma_readahead Miaohe Lin
2022-05-12 13:26 ` David Hildenbrand
2022-05-18 8:31 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 02/15] mm/swap: use helper macro __ATTR_RW Miaohe Lin
2022-05-12 13:28 ` David Hildenbrand
2022-05-18 8:46 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 03/15] mm/swap: fold __swap_info_get() into its sole caller Miaohe Lin
2022-05-12 13:29 ` David Hildenbrand
2022-05-18 8:56 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 04/15] mm/swap: remove unneeded return value of free_swap_slot Miaohe Lin
2022-05-12 13:30 ` David Hildenbrand
2022-05-18 9:00 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 05/15] mm/swap: print bad swap offset entry in get_swap_device Miaohe Lin
2022-05-12 13:32 ` David Hildenbrand
2022-05-18 9:36 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 06/15] mm/swap: remove buggy cache->nr check in refill_swap_slots_cache Miaohe Lin
2022-05-12 13:37 ` David Hildenbrand
2022-05-16 2:00 ` Miaohe Lin
2022-05-17 23:39 ` Andrew Morton
2022-05-18 9:37 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 07/15] mm/swap: remove unneeded p != NULL check in __swap_duplicate Miaohe Lin
2022-05-12 13:37 ` David Hildenbrand
2022-05-18 9:40 ` Oscar Salvador
2022-05-09 13:14 ` [PATCH 08/15] mm/swap: make page_swapcount and __lru_add_drain_all Miaohe Lin
2022-05-12 13:39 ` David Hildenbrand
2022-05-18 9:46 ` Oscar Salvador
2022-05-19 1:54 ` Miaohe Lin
2022-05-09 13:14 ` [PATCH 09/15] mm/swap: avoid calling swp_swap_info when try to check SWP_STABLE_WRITES Miaohe Lin
2022-05-10 0:28 ` NeilBrown
2022-05-10 2:21 ` Miaohe Lin
2022-05-17 23:39 ` Andrew Morton
2022-05-09 13:14 ` [PATCH 10/15] mm/swap: break the loop if matching device is found Miaohe Lin
2022-05-09 21:16 ` Andrew Morton [this message]
2022-05-10 2:10 ` Miaohe Lin
2022-05-09 13:14 ` [PATCH 11/15] mm/swap: add helper swap_offset_available() Miaohe Lin
2022-05-10 0:45 ` NeilBrown
2022-05-10 2:03 ` Miaohe Lin
2022-05-17 23:39 ` Andrew Morton
2022-05-09 13:14 ` [PATCH 12/15] mm/swap: fix the obsolete comment for SWP_TYPE_SHIFT Miaohe Lin
2022-05-12 13:41 ` David Hildenbrand
2022-05-09 13:14 ` [PATCH 13/15] mm/swap: clean up the comment of find_next_to_unuse Miaohe Lin
2022-05-12 13:42 ` David Hildenbrand
2022-05-09 13:14 ` [PATCH 14/15] mm/swap: fix the comment of get_kernel_pages Miaohe Lin
2022-05-12 13:45 ` David Hildenbrand
2022-05-13 6:15 ` Miaohe Lin
2022-05-17 23:39 ` Andrew Morton
2022-05-09 13:14 ` [PATCH 15/15] mm/swap: fix comment about swap extent Miaohe Lin
2022-05-17 23:42 ` [PATCH 00/15] A few cleanup patches for swap Andrew Morton
2022-05-18 1:52 ` Miaohe Lin
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=20220509141602.b6be120b80d0ab3218fe619a@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=david@redhat.com \
--cc=dhowells@redhat.com \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=naoya.horiguchi@nec.com \
--cc=neilb@suse.de \
--cc=peterx@redhat.com \
--cc=surenb@google.com \
--cc=vbabka@suse.cz \
--cc=willy@infradead.org \
/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).