Commit 2bd3488f authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/uv changes from Ingo Molnar:
 "UV2 BAU productization fixes.

  The BAU (Broadcast Assist Unit) is SGI's fancy out of line way on UV
  hardware to do TLB flushes, instead of the normal APIC IPI methods.
  The commits here fix / work around hangs in their latest hardware
  iteration (UV2).

  My understanding is that the main purpose of the out of line
  signalling channel is to improve scalability: the UV APIC hardware
  glue does not handle broadcasting to many CPUs very well, and this
  matters most for TLB shootdowns.

  [ I don't agree with all aspects of the current approach: in hindsight
    it would have been better to link the BAU at the IPI/APIC driver
    level instead of the TLB shootdown level, where TLB flushes are
    really just one of the uses of broadcast SMP messages.  Doing that
    would improve scalability in some other ways and it would also
    remove a few uglies from the TLB path.  It would also be nice to
    push more is_uv_system() tests into proper x86_init or x86_platform
    callbacks.  Cliff? ]"

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/uv: Work around UV2 BAU hangs
  x86/uv: Implement UV BAU runtime enable and disable control via /proc/sgi_uv/
  x86/uv: Fix the UV BAU destination timeout period
parents d5d96ed2 8b6e511e
......@@ -140,6 +140,9 @@
#define IPI_RESET_LIMIT 1
/* after this # consecutive successes, bump up the throttle if it was lowered */
#define COMPLETE_THRESHOLD 5
/* after this # of giveups (fall back to kernel IPI's) disable the use of
the BAU for a period of time */
#define GIVEUP_LIMIT 100
#define UV_LB_SUBNODEID 0x10
......@@ -166,7 +169,6 @@
#define FLUSH_RETRY_TIMEOUT 2
#define FLUSH_GIVEUP 3
#define FLUSH_COMPLETE 4
#define FLUSH_RETRY_BUSYBUG 5
/*
* tuning the action when the numalink network is extremely delayed
......@@ -175,7 +177,7 @@
microseconds */
#define CONGESTED_REPS 10 /* long delays averaged over
this many broadcasts */
#define CONGESTED_PERIOD 30 /* time for the bau to be
#define DISABLED_PERIOD 10 /* time for the bau to be
disabled, in seconds */
/* see msg_type: */
#define MSG_NOOP 0
......@@ -520,6 +522,12 @@ struct ptc_stats {
unsigned long s_uv2_wars; /* uv2 workaround, perm. busy */
unsigned long s_uv2_wars_hw; /* uv2 workaround, hiwater */
unsigned long s_uv2_war_waits; /* uv2 workaround, long waits */
unsigned long s_overipilimit; /* over the ipi reset limit */
unsigned long s_giveuplimit; /* disables, over giveup limit*/
unsigned long s_enters; /* entries to the driver */
unsigned long s_ipifordisabled; /* fall back to IPI; disabled */
unsigned long s_plugged; /* plugged by h/w bug*/
unsigned long s_congested; /* giveup on long wait */
/* destination statistics */
unsigned long d_alltlb; /* times all tlb's on this
cpu were flushed */
......@@ -586,8 +594,8 @@ struct bau_control {
int timeout_tries;
int ipi_attempts;
int conseccompletes;
int baudisabled;
int set_bau_off;
short nobau;
short baudisabled;
short cpu;
short osnode;
short uvhub_cpu;
......@@ -596,14 +604,16 @@ struct bau_control {
short cpus_in_socket;
short cpus_in_uvhub;
short partition_base_pnode;
short using_desc; /* an index, like uvhub_cpu */
unsigned int inuse_map;
short busy; /* all were busy (war) */
unsigned short message_number;
unsigned short uvhub_quiesce;
short socket_acknowledge_count[DEST_Q_SIZE];
cycles_t send_message;
cycles_t period_end;
cycles_t period_time;
spinlock_t uvhub_lock;
spinlock_t queue_lock;
spinlock_t disable_lock;
/* tunables */
int max_concurr;
int max_concurr_const;
......@@ -614,9 +624,9 @@ struct bau_control {
int complete_threshold;
int cong_response_us;
int cong_reps;
int cong_period;
unsigned long clocks_per_100_usec;
cycles_t period_time;
cycles_t disabled_period;
int period_giveups;
int giveup_limit;
long period_requests;
struct hub_and_pnode *thp;
};
......
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