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Commit 0b184a30 authored by Matt Fleming's avatar Matt Fleming Committed by Tony Luck
Browse files

ia64: Reduce stack usage by iterating over nodemask 



GCC complains about sn2_global_tlb_purge() because of the large stack
required by the function,

  arch/ia64/sn/kernel/sn2/sn2_smp.c: In function 'sn2_global_tlb_purge':
  arch/ia64/sn/kernel/sn2/sn2_smp.c:319:1: warning: the frame size of 2176 bytes is larger than 2048 bytes [-Wframe-larger-than=]

2048 bytes of the stack are consumed by the node ID array 'nasids[]'.
But we don't actually need to put the ID array on the stack and can
use nodemask operations.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 1bba3ff9

arch/ia64/sn/kernel/sn2/sn2_smp.c

+23 −12
Original line number Diff line number Diff line
@@ -54,7 +54,7 @@ sn2_ptc_deadlock_recovery_core(volatile unsigned long *, unsigned long, 
			       volatile unsigned long *, unsigned long,

			       volatile unsigned long *, unsigned long);

void

sn2_ptc_deadlock_recovery(short *, short, short, int,

sn2_ptc_deadlock_recovery(nodemask_t, short, short, int,

			  volatile unsigned long *, unsigned long,

			  volatile unsigned long *, unsigned long);
@@ -169,7 +169,7 @@ sn2_global_tlb_purge(struct mm_struct *mm, unsigned long start, 
	int use_cpu_ptcga;

	volatile unsigned long *ptc0, *ptc1;

	unsigned long itc, itc2, flags, data0 = 0, data1 = 0, rr_value, old_rr = 0;

	short nasids[MAX_NUMNODES], nix;

	short nix;

	nodemask_t nodes_flushed;

	int active, max_active, deadlock, flush_opt = sn2_flush_opt;
@@ -218,9 +218,7 @@ sn2_global_tlb_purge(struct mm_struct *mm, unsigned long start, 
	}



	itc = ia64_get_itc();

	nix = 0;

	for_each_node_mask(cnode, nodes_flushed)

		nasids[nix++] = cnodeid_to_nasid(cnode);

	nix = nodes_weight(nodes_flushed);



	rr_value = (mm->context << 3) | REGION_NUMBER(start);
@@ -270,8 +268,10 @@ sn2_global_tlb_purge(struct mm_struct *mm, unsigned long start, 
			data0 = (data0 & ~SH2_PTC_ADDR_MASK) | (start & SH2_PTC_ADDR_MASK);

		deadlock = 0;

		active = 0;

		for (ibegin = 0, i = 0; i < nix; i++) {

			nasid = nasids[i];

		ibegin = 0;

		i = 0;

		for_each_node_mask(cnode, nodes_flushed) {

			nasid = cnodeid_to_nasid(cnode);

			if (use_cpu_ptcga && unlikely(nasid == mynasid)) {

				ia64_ptcga(start, nbits << 2);

				ia64_srlz_i();
@@ -286,13 +286,14 @@ sn2_global_tlb_purge(struct mm_struct *mm, unsigned long start, 
				if ((deadlock = wait_piowc())) {

					if (flush_opt == 1)

						goto done;

					sn2_ptc_deadlock_recovery(nasids, ibegin, i, mynasid, ptc0, data0, ptc1, data1);

					sn2_ptc_deadlock_recovery(nodes_flushed, ibegin, i, mynasid, ptc0, data0, ptc1, data1);

					if (reset_max_active_on_deadlock())

						max_active = 1;

				}

				active = 0;

				ibegin = i + 1;

			}

			i++;

		}

		start += (1UL << nbits);

	} while (start < end);
@@ -327,11 +328,12 @@ sn2_global_tlb_purge(struct mm_struct *mm, unsigned long start, 
 */



void

sn2_ptc_deadlock_recovery(short *nasids, short ib, short ie, int mynasid,

sn2_ptc_deadlock_recovery(nodemask_t nodes, short ib, short ie, int mynasid,

			  volatile unsigned long *ptc0, unsigned long data0,

			  volatile unsigned long *ptc1, unsigned long data1)

{

	short nasid, i;

	int cnode;

	unsigned long *piows, zeroval, n;



	__this_cpu_inc(ptcstats.deadlocks);
@@ -339,17 +341,26 @@ sn2_ptc_deadlock_recovery(short *nasids, short ib, short ie, int mynasid, 
	piows = (unsigned long *) pda->pio_write_status_addr;

	zeroval = pda->pio_write_status_val;



	i = 0;

	for_each_node_mask(cnode, nodes) {

		if (i < ib)

			goto next;



		if (i > ie)

			break;



	for (i=ib; i <= ie; i++) {

		nasid = nasids[i];

		nasid = cnodeid_to_nasid(cnode);

		if (local_node_uses_ptc_ga(is_shub1()) && nasid == mynasid)

			continue;

			goto next;



		ptc0 = CHANGE_NASID(nasid, ptc0);

		if (ptc1)

			ptc1 = CHANGE_NASID(nasid, ptc1);



		n = sn2_ptc_deadlock_recovery_core(ptc0, data0, ptc1, data1, piows, zeroval);

		__this_cpu_add(ptcstats.deadlocks2, n);

next:

		i++;

	}



}