From: "Dan Maas" <dmaas@dcine.com>
To: "chiranjeevi vaka" <cvaka_kernel@yahoo.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: Re: using kmalloc
Date: Wed, 20 Mar 2002 00:53:20 -0500 [thread overview]
Message-ID: <010101c1cfd3$8a87cfd0$1a02a8c0@allyourbase> (raw)
In-Reply-To: <fa.l19uvvv.1hjmo8t@ifi.uio.no>
> I am getting some problems with kmalloc. If I tried to
> allocate more than certain memory then the system is
> hanging while booting with the changed kernel. Can you
> suggest me how to come out this situation. Can't I
> allocate as much I want when I want to allocate in the
> kernel.
kmalloc() allocates physically-contiguous pages of memory. Due to
fragmentation, more than 64KB-128KB of contiguous pages might not be
available, and hence kmalloc() will fail.
To allocate more memory, use vmalloc(), which allocates and maps physically
disjoint pages into a virtually-contiguous region. Be careful when doing DMA
to a vmalloc() area, since it is not physically contiguous and exists only
in the kernel's virtual memory map... Also I believe vmalloc()ed memory is
only accessible from (the context of) the process in which it was allocated
(?).
Regards,
Dan
next parent reply other threads:[~2002-03-20 5:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <fa.l19uvvv.1hjmo8t@ifi.uio.no>
2002-03-20 5:53 ` Dan Maas [this message]
2002-03-20 10:27 ` Alan Cox
2002-03-20 11:48 ` Jan Hudec
[not found] <OFD9F443C5.CB1A619A-ON88256B81.005F0AD1@boulder.ibm.com>
2002-03-19 19:26 ` chiranjeevi vaka
2002-03-19 19:38 ` Tommy Reynolds
2002-03-19 16:18 chiranjeevi vaka
2002-03-19 16:41 ` Arnaldo Carvalho de Melo
2002-03-19 17:30 ` yodaiken
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