On 8/27/2021 7:24 AM, Takashi Yano wrote:
On Thu, 26 Aug 2021 18:18:29 -0400
Ken Brown wrote:
On 8/26/2021 11:56 AM, Ken Brown via Cygwin wrote:
[...]
In case you want to try out my proposed change, I've just rebased the patches to
the current master and pushed them to a new topic/pipe branch.
Hi Ken,
Thanks much! I tested topic/pipe branch.
[yano@cygwin-PC ~]$ scp test.dat yano@linux-server:.
yano@linux-server's password:
test.dat 100% 100MB 95.9MB/s 00:01
[yano@cygwin-PC ~]$ scp yano@linux-server:test.dat .
yano@linux-server's password:
test.dat 100% 100MB 8.0MB/s 00:12
yano@linux-server:~$ scp yano@cygwin-PC:test.dat .
yano@cygwin-PC's password:
test.dat 100% 100MB 109.7MB/s 00:00
yano@linux-server:~$ scp test.dat yano@cygwin-PC:.
yano@cygwin-PC's password:
test.dat 100% 100MB 31.4MB/s 00:03
As shown above, outgoing transfer-rate has been improved upto near
theoretical limit. However, incoming transfer-rate is not improved
much.
I digged further and found the first patch attached solves the issue
as follows.
[yano@cygwin-PC ~]$ scp yano@linux-server:test.dat .
yano@linux-server's password:
test.dat 100% 100MB 112.8MB/s 00:00
yano@linux-server2:~$ scp test.dat yano@cygwin-PC:.
yano@cygwin-PC's password:
test.dat 100% 100MB 102.5MB/s 00:00
Great!
I also tested the case:
https://cygwin.com/pipermail/cygwin/2021-March/247987.html
which seems to be the same issue with
https://stackoverflow.com/questions/10385424/good-alternatives-to-cygwin-cygwin-doesnt-support-natively-support-win32-app
Unfortunately, topic/pipe does not help.
I confirmed that applying the second patch attached, which reverts
to create() rather than nt_create(), and setting CYGWIN=pipe_byte
fixes the problem.
What do you think of this alternative implementation which does
not use nt_create()?
Two years ago I thought I needed nt_create to avoid problems when calling
set_pipe_non_blocking. Are you saying that's not an issue? Is
set_pipe_non_blocking unnecessary? Is that the point of your modification to
raw_read?
Ken
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