Commit 79e1c242 authored by Ye Liu's avatar Ye Liu Committed by Andrew Morton
Browse files

mm: replace (20 - PAGE_SHIFT) with common macros for pages<->MB conversion 

Replace repeated (20 - PAGE_SHIFT) calculations with standard macros:
- MB_TO_PAGES(mb)    converts MB to page count
- PAGES_TO_MB(pages) converts pages to MB

No functional change.

[akpm@linux-foundation.org: remove arc's private PAGES_TO_MB, remove its unused PAGES_TO_KB]
[akpm@linux-foundation.org: don't include mm.h due to include file ordering mess]
Link: https://lkml.kernel.org/r/20250718024134.1304745-1-ye.liu@linux.dev


Signed-off-by: default avatarYe Liu <liuye@kylinos.cn>
Acked-by: default avatarZi Yan <ziy@nvidia.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: default avatarDev Jain <dev.jain@arm.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarChris Li <chrisl@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lai jiangshan <jiangshanlai@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 849d5cff

arch/arc/include/asm/arcregs.h

+0 −3
Original line number Diff line number Diff line
@@ -151,9 +151,6 @@ 
/* Helpers */

#define TO_KB(bytes)		((bytes) >> 10)

#define TO_MB(bytes)		(TO_KB(bytes) >> 10)

#define PAGES_TO_KB(n_pages)	((n_pages) << (PAGE_SHIFT - 10))

#define PAGES_TO_MB(n_pages)	(PAGES_TO_KB(n_pages) >> 10)





/*

 ***************************************************************

include/linux/mm.h

+9 −0
Original line number Diff line number Diff line
@@ -69,6 +69,15 @@ static inline void totalram_pages_add(long count) 


extern void * high_memory;



/*

 * Convert between pages and MB

 * 20 is the shift for 1MB (2^20 = 1MB)

 * PAGE_SHIFT is the shift for page size (e.g., 12 for 4KB pages)

 * So (20 - PAGE_SHIFT) converts between pages and MB

 */

#define PAGES_TO_MB(pages) ((pages) >> (20 - PAGE_SHIFT))

#define MB_TO_PAGES(mb)    ((mb) << (20 - PAGE_SHIFT))



#ifdef CONFIG_SYSCTL

extern int sysctl_legacy_va_layout;

#else

kernel/rcu/rcuscale.c

+1 −1
Original line number Diff line number Diff line
@@ -796,7 +796,7 @@ kfree_scale_thread(void *arg) 
		pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n",

		       (unsigned long long)(end_time - start_time), kfree_loops,

		       rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),

		       (mem_begin - mem_during) >> (20 - PAGE_SHIFT));

		       PAGES_TO_MB(mem_begin - mem_during));



		if (shutdown) {

			smp_mb(); /* Assign before wake. */

kernel/sched/fair.c

+2 −3
Original line number Diff line number Diff line
@@ -1495,7 +1495,7 @@ static unsigned int task_nr_scan_windows(struct task_struct *p) 
	 * by the PTE scanner and NUMA hinting faults should be trapped based

	 * on resident pages

	 */

	nr_scan_pages = sysctl_numa_balancing_scan_size << (20 - PAGE_SHIFT);

	nr_scan_pages = MB_TO_PAGES(sysctl_numa_balancing_scan_size);

	rss = get_mm_rss(p->mm);

	if (!rss)

		rss = nr_scan_pages;
@@ -1934,8 +1934,7 @@ bool should_numa_migrate_memory(struct task_struct *p, struct folio *folio, 
		}



		def_th = sysctl_numa_balancing_hot_threshold;

		rate_limit = sysctl_numa_balancing_promote_rate_limit << \

			(20 - PAGE_SHIFT);

		rate_limit = MB_TO_PAGES(sysctl_numa_balancing_promote_rate_limit);

		numa_promotion_adjust_threshold(pgdat, rate_limit, def_th);



		th = pgdat->nbp_threshold ? : def_th;

mm/backing-dev.c

+1 −1
Original line number Diff line number Diff line
@@ -510,7 +510,7 @@ static void wb_update_bandwidth_workfn(struct work_struct *work) 
/*

 * Initial write bandwidth: 100 MB/s

 */

#define INIT_BW		(100 << (20 - PAGE_SHIFT))

#define INIT_BW		MB_TO_PAGES(100)



static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,

		   gfp_t gfp)