The patch titled
Subject: mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4
has been added to the -mm tree. Its filename is
mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4.patch
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------------------------------------------------------
From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Subject: mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4
Changes from v3:
- multi line comment style changes
- minor code style changes
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
Cc: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/vmcore.c | 86 +++++++++++++++++++++------------------------
1 file changed, 42 insertions(+), 44 deletions(-)
diff -puN fs/proc/vmcore.c~mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4 fs/proc/vmcore.c
--- a/fs/proc/vmcore.c~mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4
+++ a/fs/proc/vmcore.c
@@ -329,20 +329,20 @@ static inline char *alloc_elfnotes_buf(s
*/
#ifdef CONFIG_MMU
/*
- * remap_oldmem_pfn_checked - do remap_oldmem_pfn replacing all pages reported
- * as not being ram with the zero page.
+ * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages
+ * reported as not being ram with the zero page.
*
* @vma: vm_area_struct describing requested mapping
- * @vma_addr: start remapping from
+ * @from: start remapping from
* @pfn: page frame number to start remapping to
* @size: remapping size
+ * @prot: protection bits
*
- * Returns the remapped length. If no errors were hit during the remapping it
- * should be equal to size.
+ * Returns zero on success, -EAGAIN on failure.
*/
-static u64 remap_oldmem_pfn_checked(struct vm_area_struct *vma,
- unsigned long vma_addr, unsigned long pfn,
- unsigned long size)
+int remap_oldmem_pfn_checked(struct vm_area_struct *vma, unsigned long from,
+ unsigned long pfn, unsigned long size,
+ pgprot_t prot)
{
size_t map_size;
unsigned long pos_start, pos_end, pos;
@@ -354,25 +354,25 @@ static u64 remap_oldmem_pfn_checked(stru
for (pos = pos_start; pos < pos_end; ++pos) {
if (!pfn_is_ram(pos)) {
- /* We hit a page which is not ram. Remap the continuous
+ /*
+ * We hit a page which is not ram. Remap the continuous
* region between pos_start and pos-1 and replace
* the non-ram page at pos with the zero page.
*/
if (pos > pos_start) {
/* Remap continuous region */
map_size = (pos - pos_start) << PAGE_SHIFT;
- if (remap_oldmem_pfn_range(vma, vma_addr + len,
+ if (remap_oldmem_pfn_range(vma, from + len,
pos_start, map_size,
- vma->vm_page_prot))
- return len;
+ prot))
+ goto fail;
len += map_size;
}
/* Remap the zero page */
- if (remap_oldmem_pfn_range(vma, vma_addr + len,
+ if (remap_oldmem_pfn_range(vma, from + len,
zeropage_pfn,
- PAGE_SIZE,
- vma->vm_page_prot))
- return len;
+ PAGE_SIZE, prot))
+ goto fail;
len += PAGE_SIZE;
pos_start = pos + 1;
}
@@ -380,13 +380,29 @@ static u64 remap_oldmem_pfn_checked(stru
if (pos > pos_start) {
/* Remap the rest */
map_size = (pos - pos_start) << PAGE_SHIFT;
- if (remap_oldmem_pfn_range(vma, vma_addr + len, pos_start,
- map_size,
- vma->vm_page_prot))
- return len;
+ if (remap_oldmem_pfn_range(vma, from + len, pos_start,
+ map_size, vma->vm_page_prot))
+ goto fail;
len += map_size;
}
- return len;
+ return 0;
+fail:
+ do_munmap(vma->vm_mm, from, len);
+ return -EAGAIN;
+}
+
+int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
+ unsigned long from, unsigned long pfn,
+ unsigned long size, pgprot_t prot)
+{
+ /*
+ * Check if oldmem_pfn_is_ram was registered to avoid
+ * looping over all pages without a reason.
+ */
+ if (oldmem_pfn_is_ram)
+ return remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
+ else
+ return remap_oldmem_pfn_range(vma, from, pfn, size, prot);
}
static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
@@ -448,31 +464,13 @@ static int mmap_vmcore(struct file *file
tsz = min_t(size_t, m->offset + m->size - start, size);
paddr = m->paddr + start - m->offset;
-
- /* Check if oldmem_pfn_is_ram was registered to avoid
- looping over all pages without a reason. */
- if (oldmem_pfn_is_ram) {
- u64 original_len;
- unsigned long pfn, vma_addr;
-
- pfn = paddr >> PAGE_SHIFT;
- vma_addr = vma->vm_start + len;
- original_len = len;
- len += remap_oldmem_pfn_checked(vma, vma_addr,
- pfn, tsz);
- if (len != original_len + tsz)
- goto fail;
- } else {
- if (remap_oldmem_pfn_range(vma,
- vma->vm_start + len,
- paddr >> PAGE_SHIFT,
- tsz,
- vma->vm_page_prot))
- goto fail;
- len += tsz;
- }
+ if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,
+ paddr >> PAGE_SHIFT, tsz,
+ vma->vm_page_prot))
+ goto fail;
size -= tsz;
start += tsz;
+ len += tsz;
if (size == 0)
return 0;
_
Patches currently in -mm which might be from vkuznets@xxxxxxxxxx are
mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors.patch
mmap_vmcore-skip-non-ram-pages-reported-by-hypervisors-v4.patch
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