Eric Lee / smarc-ti-linux-kernel

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Commit a18ff1bde0c3da9ece3ba60e6eae2ef87f91a12e

Authored by Jeff Dike
Committed by Linus Torvalds
1 parent 57ac895a7f
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

uml: speed up exec 

flush_thread doesn't need to do a full page table walk in order to clear the
address space.  It knows what the end result needs to be, so it can call unmap
directly.

This results in a 10-20% speedup in an exec from bash.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 11 additions and 1 deletions Side-by-side Diff

arch/um/kernel/skas/exec.c
Diff comments   View file @ a18ff1b
... ... @@ -17,7 +17,17 @@
17 17  
18 18 void flush_thread_skas(void)
19 19 {
20   - force_flush_all();
  20 + void *data = NULL;
  21 + unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
  22 + int ret;
  23 +
  24 + ret = unmap(&current->mm->context.skas.id, 0, end, 1, &data);
  25 + if(ret){
  26 + printk("flush_thread_skas - clearing address space failed, "
  27 + "err = %d\n", ret);
  28 + force_sig(SIGKILL, current);
  29 + }
  30 +
21 31 switch_mm_skas(&current->mm->context.skas.id);
22 32 }
23 33