From: Junio C Hamano <gitster@pobox.com>
To: "Torsten Bögershausen" <tboegi@web.de>
Cc: randall.s.becker@rogers.com, git@vger.kernel.org,
"Randall S. Becker" <rsbecker@nexbridge.com>
Subject: Re: [PATCH v2 0/6] Force pipes to flush immediately on NonStop platform
Date: Mon, 22 Jan 2018 14:36:03 -0800 [thread overview]
Message-ID: <xmqqshaxjzcc.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20180120111012.GA26459@tor.lan> ("Torsten Bögershausen"'s message of "Sat, 20 Jan 2018 12:10:12 +0100")
Torsten Bögershausen <tboegi@web.de> writes:
> On Fri, Jan 19, 2018 at 12:33:59PM -0500, randall.s.becker@rogers.com wrote:
>> From: "Randall S. Becker" <rsbecker@nexbridge.com>
>>
>> * wrapper.c: called setbuf(stream,0) to force pipe flushes not enabled by
>> default on the NonStop platform.
>>
>> Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com>
>> ---
>> wrapper.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/wrapper.c b/wrapper.c
>> index d20356a77..671cbb4b4 100644
>> --- a/wrapper.c
>> +++ b/wrapper.c
>> @@ -403,6 +403,9 @@ FILE *xfdopen(int fd, const char *mode)
>> FILE *stream = fdopen(fd, mode);
>> if (stream == NULL)
>> die_errno("Out of memory? fdopen failed");
>> +#ifdef __TANDEM
>> + setbuf(stream,0);
>> +#endif
>
> Reading the commit message, I would have expected someting similar to
>
> #ifdef FORCE_PIPE_FLUSHES
> setbuf(stream,0);
> #endif
>
> (Because other systems may need the tweak as well, some day)
> Of course you need to change that in the Makefile and config.mak.uname
I actually wouldn't have expected anything like that after reading
the commit message.
First I thought it was describing only what it does (i.e. "let's use
setbuf() to set the stream unbuffered on TANDEM"), which is a
useless description that only says what it does which we can read
from the diff, but "NonStop by default creates pipe that does not
flush" is a potentially useful information the log message adds.
But it is just "potentially"---we cannot read what exact problem the
change is trying to address. Making a pipe totally unbuffered is a
heavy hammer that may not be an appropriate solution---it could be
that we are missing calls to fflush() where we need and have been
lucky because most of the systems we deal with do line-buffered by
default, or something silly/implausible like that, and if that is
the case, a more proper fix may be to add these missing fflush() to
right places.
IOW, I do not see it explained clearly why this change is needed on
any single platform---so "that issue may be shared by others, too"
is a bit premature thing for me to listen to and understand, as
"that issue" is quite unclear to me.
next prev parent reply other threads:[~2018-01-22 22:36 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-19 17:33 [PATCH v2 0/6] Force pipes to flush immediately on NonStop platform randall.s.becker
2018-01-19 17:34 ` [PATCH v2 0/6] Cover Letter for NonStop Port Patches randall.s.becker
2018-01-19 17:34 ` [PATCH v2 1/6] Bypass GCC attributes on NonStop platform where used randall.s.becker
2018-01-19 19:25 ` Stefan Beller
2018-01-19 20:28 ` Ramsay Jones
2018-01-19 21:20 ` Jeff King
2018-01-19 22:43 ` Ramsay Jones
2018-01-19 22:53 ` Randall S. Becker
2018-01-19 17:34 ` [PATCH v2 2/6] Add tar extract install options override in installation processing randall.s.becker
2018-01-20 12:30 ` René Scharfe
2018-01-20 13:44 ` Randall S. Becker
2018-01-20 14:24 ` René Scharfe
2018-01-20 15:35 ` Randall S. Becker
2018-01-20 20:34 ` Ævar Arnfjörð Bjarmason
2018-01-20 20:52 ` Randall S. Becker
2018-01-19 17:34 ` [PATCH v2 3/6] Define config options required for the HPE NonStop NSX and NSE platforms randall.s.becker
2018-01-19 17:34 ` [PATCH v2 4/6] Force test suite traps to be cleared for NonStop ksh randall.s.becker
2018-01-19 19:55 ` Stefan Beller
2018-01-19 21:27 ` Jeff King
2018-01-19 22:29 ` Randall S. Becker
2018-01-19 23:29 ` Randall S. Becker
2018-01-21 4:07 ` Randall S. Becker
2018-01-19 17:34 ` [PATCH v2 5/6] Bring NonStop platform definitions up to date in git-compat-util.h randall.s.becker
2018-01-19 17:34 ` [PATCH v2 6/6] Add intptr_t and uintptr_t to regcomp.c for NonStop platform randall.s.becker
2018-01-19 19:34 ` [PATCH v2 0/6] Force pipes to flush immediately on " Stefan Beller
2018-01-20 11:10 ` Torsten Bögershausen
2018-01-20 13:23 ` Randall S. Becker
2018-01-22 22:36 ` Junio C Hamano [this message]
2018-01-22 22:43 ` Randall S. Becker
2018-01-23 18:13 ` Junio C Hamano
2018-01-23 20:46 ` Randall S. Becker
2018-01-25 3:42 ` Randall S. Becker
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