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Date: | Thu, 11 May 2000 15:57:39 -0400 (EDT) |
Message-Id: | <200005111957.PAA13569@indy.delorie.com> |
From: | Eli Zaretskii <eliz AT delorie DOT com> |
To: | Martin Stromberg <Martin DOT Stromberg AT lu DOT erisoft DOT se> |
CC: | djgpp-workers AT delorie DOT com |
In-reply-to: | <200005111438.QAA05671@lws256.lu.erisoft.se> (message from Martin |
Stromberg on Thu, 11 May 2000 16:38:51 +0200 (MET DST)) | |
Subject: | Re: Perfomance of gc-simple |
References: | <200005111438 DOT QAA05671 AT lws256 DOT lu DOT erisoft DOT se> |
Reply-To: | djgpp-workers AT delorie DOT com |
Errors-To: | nobody AT delorie DOT com |
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X-Unsubscribes-To: | listserv AT delorie DOT com |
> From: Martin Stromberg <Martin DOT Stromberg AT lu DOT erisoft DOT se> > Date: Thu, 11 May 2000 16:38:51 +0200 (MET DST) > > But Solaris' man page says: > "The use of MAP_FIXED is discouraged, as it may prevent an > implementation from making the most effective use of system > resources." > > I also saw a similar statement on Linux. > > So it's strange that a test for mmap() uses a feature that is > discouraged! It uses MAP_FIXED because Grep uses it. And Grep uses it because it does an mmap on each file it processes, and it doesn't want to relocate the working buffer each time, I guess. Anyway, Grep only uses mmap when given a special command-line option now, since using mmap can lose in some rare cases where the normal I/O wins. I guess that covers the discouragement as well ;-).
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