Date: Fri, 06 Nov 1998 13:14:31 +0100 From: Tor.Egge@fast.no To: dillon@apollo.backplane.com Cc: cvs-committers@FreeBSD.ORG Subject: Re: sendfile.2 (was Re: cvs commit: ...) Message-ID: <199811061214.NAA01603@midten.fast.no> In-Reply-To: Your message of "Thu, 5 Nov 1998 20:01:20 -0800 (PST)" References: <199811060401.UAA00767@apollo.backplane.com>
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> :> would be to actually use it in the stdio library for read operations > :> on plain files: [f]getc(), fgets(), and fread(). The only difficulty > :> here is in how to deal with file truncation issues, since accessing > :> mmap'd pages beyond the file's size will segfault. > : > :For what its worth, the SFIO library from AT&T already supports > :this. I don't remember what copyright it is released under though. > : > :Koshy > :<jkoshy@freebsd.org> > > Well, it isn't that difficult to do... it would take maybe 20 minutes > to implement. A simple MAP_PRIVATE replacement of __srefill() and maybe > a little code to avoid unnecessary copy-on-write ops. Enabling vfs_ioopts does most of this implicitly. Unfortunately, there is a bug involved, that might cause a deadlock when reading the last "fragment" of the file. The same deadlock can be triggered by explicit use of mmap, e.g. PR 8416. - Tor Egge To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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