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* set winsize to memwinsize in initial getwindow(). makes no functional 

difference, but looks less like a debug hack leftover.
* explain memory windows vs. directio a little better in comment
This commit is contained in:
pooka 2009-10-07 09:42:14 +00:00
parent a8268fa583
commit 9759195360
1 changed files with 12 additions and 3 deletions
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15
sys/rump/librump/rumpvfs/rumpblk.c
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@ -1,4 +1,4 @@
/* $NetBSD: rumpblk.c,v 1.28 2009/10/07 09:23:03 pooka Exp $ */
/* $NetBSD: rumpblk.c,v 1.29 2009/10/07 09:42:14 pooka Exp $ */
/*
* Copyright (c) 2009 Antti Kantee. All Rights Reserved.
@ -40,10 +40,19 @@
* I/O operation. It also gives finer-grained control of how to
* flush data. Additionally, in case the rump kernel dumps core,
* we get way less carnage.
*
* However, it is quite costly in writing large amounts of
* file data, since old contents cannot merely be overwritten, but
* must be paged in first before replacing (i.e. r/m/w). Ideally,
* we should use directio. The problem is that directio can fail
* silently causing improper file system semantics (i.e. unflushed
* data). Therefore, default to mmap for now. Even so, directio
* _should_ be safe and can be enabled by compiling this module
* with -DHAS_DIRECTIO.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rumpblk.c,v 1.28 2009/10/07 09:23:03 pooka Exp $");
__KERNEL_RCSID(0, "$NetBSD: rumpblk.c,v 1.29 2009/10/07 09:42:14 pooka Exp $");
#include <sys/param.h>
#include <sys/buf.h>
@ -448,7 +457,7 @@ rumpblk_open(dev_t dev, int flag, int fmt, struct lwp *l)
* make sure a) we can mmap at all b) we have the
* necessary VA available
*/
winsize = 1;
winsize = memwinsize;
win = getwindow(rblk, off + i*memwinsize, &winsize,
&error);
if (win) {