x86, UV: Disable BAU on network congestion
authorCliff Wickman <cpw@sgi.com>
Wed, 2 Jun 2010 21:22:02 +0000 (16:22 -0500)
committerIngo Molnar <mingo@elte.hu>
Tue, 8 Jun 2010 19:13:45 +0000 (21:13 +0200)
commit50fb55acc5bbe5ee29d0a65262f4ec286b14d156
tree2099e2a96ae882b206e405976bf01725b7c4167e
parente8e5e8a8048006a12d7777a93baebd6e39496101
x86, UV: Disable BAU on network congestion

The numalink network can become so congested that TLB shootdown
using the Broadcast Assist Unit becomes slower than using IPI's.

In that case, disable the use of the BAU for a period of time.
The period is tunable.  When the period expires the use of the
BAU is re-enabled. A count of these actions is added to the
statistics file.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004a4-0a@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/include/asm/uv/uv_bau.h
arch/x86/kernel/tlb_uv.c