lkml.org 
[lkml]   [2005]   [Jul]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH mm] page fault patches: fix highpte in do_anon_page
Fix "scheduling while atomic" messages below do_anonymous_page when
CONFIG_HIGHPTE=y: must unmap and remap the page_table around page
allocation. And let's shift the usual pte_unmap to the minor_fault exit.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
---

Please don't interpret this fix as my approving the do_anonymous_page
without page_table_lock patches! I'm still averse to this special
route with different locking rules; but let's get it right for testing.

mm/memory.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

--- 2.6.13-rc3-mm3/mm/memory.c 2005-07-29 14:11:33.000000000 +0100
+++ linux/mm/memory.c 2005-07-29 20:58:54.000000000 +0100
@@ -1796,12 +1796,12 @@ do_anonymous_page(struct mm_struct *mm,
} else {
inc_page_state(cmpxchg_fail_anon_read);
}
- pte_unmap(page_table);
goto minor_fault;
}

/* This leaves the write case */
page_table_atomic_stop(mm);
+ pte_unmap(page_table);
if (unlikely(anon_vma_prepare(vma)))
goto oom;

@@ -1812,10 +1812,10 @@ do_anonymous_page(struct mm_struct *mm,
entry = maybe_mkwrite(pte_mkdirty(mk_pte(page,
vma->vm_page_prot)),
vma);
+ page_table = pte_offset_map(pmd, addr);
page_table_atomic_start(mm);

if (!ptep_cmpxchg(mm, addr, page_table, orig_entry, entry)) {
- pte_unmap(page_table);
page_cache_release(page);
inc_page_state(cmpxchg_fail_anon_write);
goto minor_fault;
@@ -1829,12 +1829,12 @@ do_anonymous_page(struct mm_struct *mm,
page_add_anon_rmap(page, vma, addr);
lru_cache_add_active(page);
inc_mm_counter(mm, rss);
- pte_unmap(page_table);
update_mmu_cache(vma, addr, entry);
lazy_mmu_prot_update(entry);

minor_fault:
page_table_atomic_stop(mm);
+ pte_unmap(page_table);
return VM_FAULT_MINOR;

oom:
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-07-30 22:18    [W:0.019 / U:2.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site