Commit 731351d1 authored by David Hildenbrand's avatar David Hildenbrand Committed by Linus Torvalds
Browse files

ia64: perfmon: don't mark buffer pages as PG_reserved 

In the old days, remap_pfn_range() required pages to be marked as
PG_reserved, so they would e.g.  never get swapped out.  This was
required for special mappings.  Nowadays, this is fully handled via the
VMA (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP inside
remap_pfn_range() to be precise).  PG_reserved is no longer required but
only a relic from the past.

So only architecture specific MM handling might require it (e.g.  to
detect them as MMIO pages).  As there are no architecture specific
checks for PageReserved() apart from MCA handling in ia64code, this can
go.  Use simple vzalloc()/vfree() instead.

Note that before calling vzalloc(), size has already been aligned to
PAGE_SIZE, no need to align again.

Link: http://lkml.kernel.org/r/20190114125903.24845-9-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d9fa9d95

arch/ia64/kernel/perfmon.c

+4 −55
Original line number Diff line number Diff line
@@ -583,17 +583,6 @@ pfm_put_task(struct task_struct *task) 
	if (task != current) put_task_struct(task);

}



static inline void

pfm_reserve_page(unsigned long a)

{

	SetPageReserved(vmalloc_to_page((void *)a));

}

static inline void

pfm_unreserve_page(unsigned long a)

{

	ClearPageReserved(vmalloc_to_page((void*)a));

}



static inline unsigned long

pfm_protect_ctx_ctxsw(pfm_context_t *x)

{
@@ -816,44 +805,6 @@ pfm_reset_msgq(pfm_context_t *ctx) 
	DPRINT(("ctx=%p msgq reset\n", ctx));

}



static void *

pfm_rvmalloc(unsigned long size)

{

	void *mem;

	unsigned long addr;



	size = PAGE_ALIGN(size);

	mem  = vzalloc(size);

	if (mem) {

		//printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);

		addr = (unsigned long)mem;

		while (size > 0) {

			pfm_reserve_page(addr);

			addr+=PAGE_SIZE;

			size-=PAGE_SIZE;

		}

	}

	return mem;

}



static void

pfm_rvfree(void *mem, unsigned long size)

{

	unsigned long addr;



	if (mem) {

		DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));

		addr = (unsigned long) mem;

		while ((long) size > 0) {

			pfm_unreserve_page(addr);

			addr+=PAGE_SIZE;

			size-=PAGE_SIZE;

		}

		vfree(mem);

	}

	return;

}



static pfm_context_t *

pfm_context_alloc(int ctx_flags)

{
@@ -1498,7 +1449,7 @@ pfm_free_smpl_buffer(pfm_context_t *ctx) 
	/*

	 * free the buffer

	 */

	pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);

	vfree(ctx->ctx_smpl_hdr);



	ctx->ctx_smpl_hdr  = NULL;

	ctx->ctx_smpl_size = 0UL;
@@ -2137,7 +2088,7 @@ doit: 
	 * All memory free operations (especially for vmalloc'ed memory)

	 * MUST be done with interrupts ENABLED.

	 */

	if (smpl_buf_addr)  pfm_rvfree(smpl_buf_addr, smpl_buf_size);

	vfree(smpl_buf_addr);



	/*

	 * return the memory used by the context
@@ -2266,10 +2217,8 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t 


	/*

	 * We do the easy to undo allocations first.

 	 *

	 * pfm_rvmalloc(), clears the buffer, so there is no leak

	 */

	smpl_buf = pfm_rvmalloc(size);

	smpl_buf = vzalloc(size);

	if (smpl_buf == NULL) {

		DPRINT(("Can't allocate sampling buffer\n"));

		return -ENOMEM;
@@ -2346,7 +2295,7 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t 
error:

	vm_area_free(vma);

error_kmem:

	pfm_rvfree(smpl_buf, size);

	vfree(smpl_buf);



	return -ENOMEM;

}

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