<div dir="ltr">2015-05-27 3:12 GMT+02:00 Le Tan <span dir="ltr"><<a href="mailto:tamlokveer@gmail.com" target="_blank">tamlokveer@gmail.com</a>></span>:<br><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
Is there an explict split between userspace and kernel in physical<br>
memory on Linux x86-64? That is, given a physical address, can I tell<br>
whether this address is from userspace or not?<br></blockquote><div style><br></div><div style>No. The same physical address can be used by both the kernel and the userspace.</div><div style>The kernel and userspace share the same physical memory.</div><div style>Any memory page can be allocated for the userspace then released (free) then re-allocated for kernel use.</div><div style><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
As far as I know, in virtual address space, the kernel will use the<br>
upper half and the userspace will use the lower half. But what about<br>
in physical address space? </blockquote><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
Thanks very much!<br>
<br>
Le<br>
<br>
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