git: 88d81453b115 - main - riscv: support PV_STATS pmap option

From: Mitchell Horne <mhorne_at_FreeBSD.org>
Date: Mon, 08 Jul 2024 14:52:33 UTC
The branch main has been updated by mhorne:

URL: https://cgit.FreeBSD.org/src/commit/?id=88d81453b1151f8b133023073f3a773dd78cdc3a

commit 88d81453b1151f8b133023073f3a773dd78cdc3a
Author:     Mitchell Horne <mhorne@FreeBSD.org>
AuthorDate: 2024-07-08 14:44:10 +0000
Commit:     Mitchell Horne <mhorne@FreeBSD.org>
CommitDate: 2024-07-08 14:44:10 +0000

    riscv: support PV_STATS pmap option
    
    It is rarely used but trivially supported; add the missing stat calls
    and enable it in LINT.
    
    Reviewed by:    markj, br (previous version), jhb (previous version)
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D45475
---
 sys/conf/options.riscv |  2 +-
 sys/riscv/conf/NOTES   |  3 +++
 sys/riscv/riscv/pmap.c | 13 ++++++++-----
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/sys/conf/options.riscv b/sys/conf/options.riscv
index 6a8df1d2f54e..5e1b76140ec7 100644
--- a/sys/conf/options.riscv
+++ b/sys/conf/options.riscv
@@ -1,3 +1,3 @@
-
 RISCV				opt_global.h	# For cpu RISCV to work
 INTRNG				opt_global.h
+PV_STATS			opt_pmap.h
diff --git a/sys/riscv/conf/NOTES b/sys/riscv/conf/NOTES
index 36d2e06fb698..102ee26811b3 100644
--- a/sys/riscv/conf/NOTES
+++ b/sys/riscv/conf/NOTES
@@ -17,6 +17,9 @@ options 	KDTRACE_HOOKS		# Kernel DTrace hooks
 options 	DDB_CTF			# Kernel ELF linker loads CTF data
 options 	RACCT_DEFAULT_TO_DISABLED # Set kern.racct.enable=0 by default
 
+# Enable detailed accounting by the PV entry allocator.
+options 	PV_STATS
+
 # RISC-V SBI console
 device		rcons
 
diff --git a/sys/riscv/riscv/pmap.c b/sys/riscv/riscv/pmap.c
index 781f6b250a18..f49f18ba87bb 100644
--- a/sys/riscv/riscv/pmap.c
+++ b/sys/riscv/riscv/pmap.c
@@ -93,7 +93,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
 /*
  *	Manages physical address maps.
  *
@@ -113,6 +112,8 @@
  *	and to when physical maps must be made correct.
  */
 
+#include "opt_pmap.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bitstring.h>
@@ -1891,7 +1892,6 @@ static const uint64_t pc_freemask[_NPCM] = {
 	[_NPCM - 1] = PC_FREEL
 };
 
-#if 0
 #ifdef PV_STATS
 static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail;
 
@@ -1916,7 +1916,6 @@ SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_count, CTLFLAG_RD, &pv_entry_count, 0,
 SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0,
 	"Current number of spare pv entries");
 #endif
-#endif /* 0 */
 
 /*
  * We are in a serious low memory condition.  Resort to
@@ -2101,7 +2100,8 @@ retry:
 				goto retry;
 			reclaimed = true;
 		}
-		/* XXX PV STATS */
+		PV_STAT(atomic_add_int(&pc_chunk_count, 1));
+		PV_STAT(atomic_add_int(&pc_chunk_allocs, 1));
 #if 0
 		dump_add_page(m->phys_addr);
 #endif
@@ -2112,6 +2112,7 @@ retry:
 		pc->pc_map[2] = PC_FREEL;
 		TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list);
 		TAILQ_INSERT_TAIL(&new_tail, pc, pc_lru);
+		PV_STAT(atomic_add_int(&pv_entry_spare, _NPCPV));
 
 		/*
 		 * The reclaim might have freed a chunk from the current pmap.
@@ -2222,6 +2223,7 @@ pmap_pv_demote_l2(pmap_t pmap, vm_offset_t va, vm_paddr_t pa,
 	TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_next);
 	m->md.pv_gen++;
 	/* Instantiate the remaining 511 pv entries. */
+	PV_STAT(atomic_add_long(&pv_entry_allocs, Ln_ENTRIES - 1));
 	va_last = va + L2_SIZE - PAGE_SIZE;
 	for (;;) {
 		pc = TAILQ_FIRST(&pmap->pm_pvchunk);
@@ -2250,7 +2252,8 @@ out:
 		TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
 		TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list);
 	}
-	/* XXX PV stats */
+	PV_STAT(atomic_add_long(&pv_entry_count, Ln_ENTRIES - 1));
+	PV_STAT(atomic_add_int(&pv_entry_spare, -(Ln_ENTRIES - 1)));
 }
 
 #if VM_NRESERVLEVEL > 0