Attachment 122693 Details for Bug 165929 – mmap-doc.patch

[patch] mmap-doc.patch

mmap-doc.patch (text/plain), 1.63 KB, created by Joel Ray Holveck on 2012-03-11 11:30:10 UTC

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Creator: Joel Ray Holveck

Created: 2012-03-11 11:30:10 UTC

Size: 1.63 KB

patch

obsolete

>--- lib/libc/sys/mmap.2.orig	2012-03-10 19:49:31.000000000 -0800
>+++ lib/libc/sys/mmap.2	2012-03-10 20:03:59.000000000 -0800
>@@ -205,12 +205,9 @@
> system call generally do not flush dirty NOSYNC VM data.
> The
> .Xr msync 2
>-system call is obsolete since
>-.Bx
>-implements a coherent file system buffer cache.
>-However, it may be
>-used to associate dirty VM pages with file system buffers and thus cause
>-them to be flushed to physical media sooner rather than later.
>+system call may be used to associate dirty VM pages with file system
>+buffers and thus cause them to be flushed to physical media sooner
>+rather than later.
> .It Dv MAP_PREFAULT_READ
> Immediately update the calling process's lowest-level virtual address
> translation structures, such as its page table, so that every memory
>--- lib/libc/sys/msync.2.orig	2012-03-10 20:05:18.000000000 -0800
>+++ lib/libc/sys/msync.2	2012-03-10 20:07:20.000000000 -0800
>@@ -113,9 +113,16 @@
> .Sh BUGS
> The
> .Fn msync
>-system call is obsolete since
>-.Bx
>-implements a coherent file system buffer cache.
>-However, it may be used to associate dirty VM pages with file system
>-buffers and thus cause them to be flushed to physical media sooner
>-rather than later.
>+system call does not report errors if dirty pages could not be written.
>+This is expected to be fixed in a future release of
>+.Fx .
>+.Pp
>+If another process, such as
>+.Xr syncer 4 ,
>+attempts to flush dirty pages on an NFS-backed file, but lacks
>+permissions on the server to do so, it may fail.  If this happens,
>+future calls to
>+.Fn msync
>+may not have any effect.  This is not a bug in
>+.Fn msync ,
>+although it may appear to be; it is actually a bug in NFS.

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Attachments on bug 165929: 122693