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

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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: David 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2019-03-05 15:47:32 -08:00 committed by Linus Torvalds
parent d9fa9d9517
commit 731351d1bd
1 changed files with 4 additions and 55 deletions
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59
arch/ia64/kernel/perfmon.c
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@ -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;
}