From: "Chen Lin" <chen45464546@163.com>
To: "Jakub Kicinski" <kuba@kernel.org>
Cc: nbd@nbd.name, john@phrozen.org, sean.wang@mediatek.com,
Mark-MC.Lee@mediatek.com, davem@davemloft.net,
edumazet@google.com, pabeni@redhat.com, matthias.bgg@gmail.com,
netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
alexander.duyck@gmail.com
Subject: Re:Re: [PATCH v4] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag
Date: Wed, 8 Jun 2022 20:43:31 +0800 (CST) [thread overview]
Message-ID: <55c80848.c37d.18143576bc9.Coremail.chen45464546@163.com> (raw)
In-Reply-To: <20220607161413.655dd63f@kernel.org>
At 2022-06-08 07:14:13, "Jakub Kicinski" <kuba@kernel.org> wrote:
>On Tue, 7 Jun 2022 07:39:11 +0800 Chen Lin wrote:
>> +static inline void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
>
>No need for inline, compiler will inline this anyway.
>
>> +{
>> + void *data;
>
>unsigned long data; then you can move the cast from the long line to
>the return statement, saving us from the strange indentation.
>
>> + data = (void *)__get_free_pages(gfp_mask |
>> + __GFP_COMP | __GFP_NOWARN,
>> + get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
>> +
>> + return data;
>> +}
I'll do it like below :
+static void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
+{
+ unsigned long data;
+ unsigned int size = mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH);
+
+ data = __get_free_pages(gfp_mask | __GFP_COMP | __GFP_NOWARN,
+ get_order(size));
+
+ return (void *)data;
+}
Through analysis of the ASM code from objdump, I confirmed that
the inline is not necessary. Thanks for your tips.
Also, I confirmed that create a new local variable 'size'
will not affect the generation of a constant 'order' parameter at compile time.
ASM code of calling 'mtk_max_lro_buf_alloc':
'mtk_max_lro_buf_alloc' inlined and 'order'(w1) is a constant 0x2
0000000000004530 <mtk_napi_rx>:
...
4a98: 52854400 mov w0, #0x2a20 // #10784
4a9c: 52800041 mov w1, #0x2 // #2
4aa0: 72a00080 movk w0, #0x4, lsl #16
4aa4: 94000000 bl 0 <__get_free_pages>
4aa8: f90033e0 str x0, [sp, #96]
0000000000000730 <mtk_rx_alloc>:
...
7fc: 2a1703e0 mov w0, w23
800: 52800041 mov w1, #0x2 // #2
804: 7140047f cmp w3, #0x1, lsl #12
808: 54fffe49 b.ls 7d0 <mtk_rx_alloc+0xa0> // b.plast
80c: 94000000 bl 0 <__get_free_pages>
The compiler is smart.
next prev parent reply other threads:[~2022-06-08 12:45 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-03 4:10 [PATCH] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev_alloc_frag Chen Lin
2022-06-03 4:24 ` Jakub Kicinski
2022-06-03 4:30 ` Felix Fietkau
2022-06-03 8:46 ` [PATCH v2] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag Chen Lin
2022-06-03 15:25 ` Alexander Duyck
2022-06-03 15:33 ` Alexander Duyck
2022-06-05 2:22 ` Chen Lin
2022-06-05 3:12 ` [PATCH v3] " Chen Lin
2022-06-06 21:34 ` Jakub Kicinski
2022-06-06 23:39 ` [PATCH v4] " Chen Lin
2022-06-07 23:14 ` Jakub Kicinski
2022-06-08 12:43 ` Chen Lin [this message]
2022-06-08 12:46 ` [PATCH v5] " Chen Lin
2022-06-09 3:50 ` patchwork-bot+netdevbpf
2022-06-03 17:25 ` [PATCH v2] " Eric Dumazet
2022-06-03 18:59 ` Jakub Kicinski
2022-06-03 19:11 ` Eric Dumazet
2022-06-03 19:55 ` Jakub Kicinski
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=55c80848.c37d.18143576bc9.Coremail.chen45464546@163.com \
--to=chen45464546@163.com \
--cc=Mark-MC.Lee@mediatek.com \
--cc=alexander.duyck@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=john@phrozen.org \
--cc=kuba@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=matthias.bgg@gmail.com \
--cc=nbd@nbd.name \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sean.wang@mediatek.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).