Messages in this thread | | | From | (bill davidsen) | Subject | Re: how do file-mapped (mmapped) pages become dirty? | Date | 28 Oct 2003 18:07:52 GMT |
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In article <006901c39d50$0b1313d0$2501a8c0@CARTMAN>, Amir Hermelin <amir@montilio.com> wrote:
| When a process mmaps a file, how does the kernel know the memory has been | written to (and hence the page is dirty)? Is this done by setting the | protected flag, and when the memory is first written to it's set to dirty? | What function is responsible for this setting? And when will the page be | written back to disk (i.e. where's the flusher located)?
At least on x86, the CPU sets the dirty bit on write, although once upon a time less capable CPUs did it the way you suggest. That said, I think copy on write is still done the way you suggest, but look at the code if you really care. Or wait for someone to tell me I'm wrong ;-)
-- bill davidsen <davidsen@tmr.com> CTO, TMR Associates, Inc Doing interesting things with little computers since 1979. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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