* [PATCH] splice: direct call for default_file_splice*()
@ 2020-01-20 20:49 Pavel Begunkov
2020-01-30 16:54 ` Christoph Hellwig
0 siblings, 1 reply; 6+ messages in thread
From: Pavel Begunkov @ 2020-01-20 20:49 UTC (permalink / raw)
To: Alexander Viro, linux-fsdevel, linux-kernel
Indirect calls could be very expensive nowadays, so try to use direct calls
whenever possible.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/splice.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/fs/splice.c b/fs/splice.c
index 6a6f30432688..91448d855ff0 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -852,15 +852,10 @@ EXPORT_SYMBOL(generic_splice_sendpage);
static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
loff_t *ppos, size_t len, unsigned int flags)
{
- ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
- loff_t *, size_t, unsigned int);
-
if (out->f_op->splice_write)
- splice_write = out->f_op->splice_write;
+ return out->f_op->splice_write(pipe, out, ppos, len, flags);
else
- splice_write = default_file_splice_write;
-
- return splice_write(pipe, out, ppos, len, flags);
+ return default_file_splice_write(pipe, out, ppos, len, flags);
}
/*
@@ -870,8 +865,6 @@ static long do_splice_to(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
- ssize_t (*splice_read)(struct file *, loff_t *,
- struct pipe_inode_info *, size_t, unsigned int);
int ret;
if (unlikely(!(in->f_mode & FMODE_READ)))
@@ -885,11 +878,9 @@ static long do_splice_to(struct file *in, loff_t *ppos,
len = MAX_RW_COUNT;
if (in->f_op->splice_read)
- splice_read = in->f_op->splice_read;
+ return in->f_op->splice_read(in, ppos, pipe, len, flags);
else
- splice_read = default_file_splice_read;
-
- return splice_read(in, ppos, pipe, len, flags);
+ return default_file_splice_read(in, ppos, pipe, len, flags);
}
/**
--
2.24.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] splice: direct call for default_file_splice*()
2020-01-20 20:49 [PATCH] splice: direct call for default_file_splice*() Pavel Begunkov
@ 2020-01-30 16:54 ` Christoph Hellwig
2020-01-31 9:52 ` Pavel Begunkov
2020-08-01 10:12 ` Pavel Begunkov
0 siblings, 2 replies; 6+ messages in thread
From: Christoph Hellwig @ 2020-01-30 16:54 UTC (permalink / raw)
To: Pavel Begunkov; +Cc: Alexander Viro, linux-fsdevel, linux-kernel
On Mon, Jan 20, 2020 at 11:49:46PM +0300, Pavel Begunkov wrote:
> Indirect calls could be very expensive nowadays, so try to use direct calls
> whenever possible.
... and independent of that your new version is much shorter and easier
to read. But it could be improved a tiny little bit further:
> if (out->f_op->splice_write)
> - splice_write = out->f_op->splice_write;
> + return out->f_op->splice_write(pipe, out, ppos, len, flags);
> else
> - splice_write = default_file_splice_write;
> -
> - return splice_write(pipe, out, ppos, len, flags);
> + return default_file_splice_write(pipe, out, ppos, len, flags);
No need for the else after an return.
> if (in->f_op->splice_read)
> - splice_read = in->f_op->splice_read;
> + return in->f_op->splice_read(in, ppos, pipe, len, flags);
> else
> - splice_read = default_file_splice_read;
> -
> - return splice_read(in, ppos, pipe, len, flags);
> + return default_file_splice_read(in, ppos, pipe, len, flags);
Same here.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] splice: direct call for default_file_splice*()
2020-01-30 16:54 ` Christoph Hellwig
@ 2020-01-31 9:52 ` Pavel Begunkov
2020-08-01 10:12 ` Pavel Begunkov
1 sibling, 0 replies; 6+ messages in thread
From: Pavel Begunkov @ 2020-01-31 9:52 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Alexander Viro, linux-fsdevel, linux-kernel
On 1/30/2020 7:54 PM, Christoph Hellwig wrote:
> On Mon, Jan 20, 2020 at 11:49:46PM +0300, Pavel Begunkov wrote:
>> Indirect calls could be very expensive nowadays, so try to use direct calls
>> whenever possible.
>
> ... and independent of that your new version is much shorter and easier
> to read. But it could be improved a tiny little bit further:
>
>> if (out->f_op->splice_write)
>> - splice_write = out->f_op->splice_write;
>> + return out->f_op->splice_write(pipe, out, ppos, len, flags);
>> else
>> - splice_write = default_file_splice_write;
>> -
>> - return splice_write(pipe, out, ppos, len, flags);
>> + return default_file_splice_write(pipe, out, ppos, len, flags);
>
> No need for the else after an return.
It generates identical binary. For this to not look sloppy, I'd add new
line between, so the same 4 lines. And this looks better for me, but
that's rather subjective.
I don't think it's worth of changing. What's the benefit?
>
>> if (in->f_op->splice_read)
>> - splice_read = in->f_op->splice_read;
>> + return in->f_op->splice_read(in, ppos, pipe, len, flags);
>> else
>> - splice_read = default_file_splice_read;
>> -
>> - return splice_read(in, ppos, pipe, len, flags);
>> + return default_file_splice_read(in, ppos, pipe, len, flags);
>
> Same here.
>
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] splice: direct call for default_file_splice*()
2020-01-30 16:54 ` Christoph Hellwig
2020-01-31 9:52 ` Pavel Begunkov
@ 2020-08-01 10:12 ` Pavel Begunkov
2020-08-01 17:41 ` Christoph Hellwig
1 sibling, 1 reply; 6+ messages in thread
From: Pavel Begunkov @ 2020-08-01 10:12 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Alexander Viro, linux-fsdevel, linux-kernel
On 30/01/2020 19:54, Christoph Hellwig wrote:
> On Mon, Jan 20, 2020 at 11:49:46PM +0300, Pavel Begunkov wrote:
>> Indirect calls could be very expensive nowadays, so try to use direct calls
>> whenever possible.
Hah, I'm surprised to find it as
00c285d0d0fe4 ("fs: simplify do_splice_from").
Christoph, even though this one is not a big deal, I'm finding the
practice of taking others patches and silently sending them as yours
own in general disgusting. Just for you to know.
>
> ... and independent of that your new version is much shorter and easier
> to read. But it could be improved a tiny little bit further:
>
>> if (out->f_op->splice_write)
>> - splice_write = out->f_op->splice_write;
>> + return out->f_op->splice_write(pipe, out, ppos, len, flags);
>> else
>> - splice_write = default_file_splice_write;
>> -
>> - return splice_write(pipe, out, ppos, len, flags);
>> + return default_file_splice_write(pipe, out, ppos, len, flags);
>
> No need for the else after an return.
>
>> if (in->f_op->splice_read)
>> - splice_read = in->f_op->splice_read;
>> + return in->f_op->splice_read(in, ppos, pipe, len, flags);
>> else
>> - splice_read = default_file_splice_read;
>> -
>> - return splice_read(in, ppos, pipe, len, flags);
>> + return default_file_splice_read(in, ppos, pipe, len, flags);
>
> Same here.
>
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] splice: direct call for default_file_splice*()
2020-08-01 10:12 ` Pavel Begunkov
@ 2020-08-01 17:41 ` Christoph Hellwig
2020-08-02 8:49 ` Pavel Begunkov
0 siblings, 1 reply; 6+ messages in thread
From: Christoph Hellwig @ 2020-08-01 17:41 UTC (permalink / raw)
To: Pavel Begunkov
Cc: Christoph Hellwig, Alexander Viro, linux-fsdevel, linux-kernel
On Sat, Aug 01, 2020 at 01:12:22PM +0300, Pavel Begunkov wrote:
> On 30/01/2020 19:54, Christoph Hellwig wrote:
> > On Mon, Jan 20, 2020 at 11:49:46PM +0300, Pavel Begunkov wrote:
> >> Indirect calls could be very expensive nowadays, so try to use direct calls
> >> whenever possible.
>
> Hah, I'm surprised to find it as
> 00c285d0d0fe4 ("fs: simplify do_splice_from").
>
> Christoph, even though this one is not a big deal, I'm finding the
> practice of taking others patches and silently sending them as yours
> own in general disgusting. Just for you to know.
Err, what makes you think I took your patch vs just not remembering
and pointlessly doing the same cleanup again? If I had rembered your
patch I would have just added to the series with your credit as I've
done for plenty other patches..
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] splice: direct call for default_file_splice*()
2020-08-01 17:41 ` Christoph Hellwig
@ 2020-08-02 8:49 ` Pavel Begunkov
0 siblings, 0 replies; 6+ messages in thread
From: Pavel Begunkov @ 2020-08-02 8:49 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Alexander Viro, linux-fsdevel, linux-kernel
On 01/08/2020 20:41, Christoph Hellwig wrote:
> On Sat, Aug 01, 2020 at 01:12:22PM +0300, Pavel Begunkov wrote:
>> On 30/01/2020 19:54, Christoph Hellwig wrote:
>>> On Mon, Jan 20, 2020 at 11:49:46PM +0300, Pavel Begunkov wrote:
>>>> Indirect calls could be very expensive nowadays, so try to use direct calls
>>>> whenever possible.
>>
>> Hah, I'm surprised to find it as
>> 00c285d0d0fe4 ("fs: simplify do_splice_from").
>>
>> Christoph, even though this one is not a big deal, I'm finding the
>> practice of taking others patches and silently sending them as yours
>> own in general disgusting. Just for you to know.
>
> Err, what makes you think I took your patch vs just not remembering
> and pointlessly doing the same cleanup again? If I had rembered your
> patch I would have just added to the series with your credit as I've
> done for plenty other patches..
I have no intention of picking it to pieces or something, it doesn't
worth our time, and glad that's by accident, but you may guess how it
looks -- you commented on it, and after not being picked, the patch
reappears slightly rebranded.
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-08-02 8:51 UTC | newest]
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2020-01-20 20:49 [PATCH] splice: direct call for default_file_splice*() Pavel Begunkov
2020-01-30 16:54 ` Christoph Hellwig
2020-01-31 9:52 ` Pavel Begunkov
2020-08-01 10:12 ` Pavel Begunkov
2020-08-01 17:41 ` Christoph Hellwig
2020-08-02 8:49 ` Pavel Begunkov
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