linux/arch/sparc64
David S. Miller dadeafdfc8 [PATCH] sparc64: Reduce ptrace cache flushing
We were flushing the D-cache excessively for ptrace() processing
and this makes debugging threads so slow as to be totally unusable.

All process page accesses via ptrace() go via access_process_vm().
This routine, for each process page, uses get_user_pages().  That
in turn does a flush_dcache_page() on the child pages before we
copy in/out the ptrace request data.

Therefore, all we need to do after the data movement is:

1) Flush the D-cache pages if the kernel maps the page to a different
   color than userspace does.
2) If we wrote to the page, we need to flush the I-cache on older cpus.

Previously we just flushed the entire cache at the end of a ptrace()
request, and that was beyond stupid.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-17 18:03:11 -07:00
..
boot Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kernel [PATCH] sparc64: Reduce ptrace cache flushing 2005-04-17 18:03:11 -07:00
lib Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
math-emu Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mm [PATCH] sparc64: Do not flush dcache for ZERO_PAGE. 2005-04-17 18:03:09 -07:00
oprofile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
prom Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
solaris Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
defconfig Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Kconfig Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Kconfig.debug Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00