Messages in this thread | | | From | Mike Frysinger <> | Date | Sat, 28 Nov 2009 13:53:35 -0500 | Subject | Re: avoiding duplicate icache flushing of shared maps on nommu |
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On Sat, Nov 28, 2009 at 10:40, Mike Frysinger wrote: > when working with FDPIC, there are many shared maps of read only text > regions (the C library, applet packages like busybox, ...) between > applications. but the current mm/nommu.c:do_mmap_pgoff() function > will issue an icache flush whenever a vma is added to a mm instead of > only doing it when the map is initially created. am i missing > something obvious here, or would a change like below be OK ? this > easily cuts the number of icache flushes during boot by 50% if not > more.
for some actual numbers, my default boot iflushes 18,562,124 bytes. with this fix, it's down to 4,528,580 bytes (a 75% shrink). with the stack fix, it's down to 989,636 bytes (a 95% shrink). -mike -- 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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