The patch titled
hugetlb reservations: move region tracking earlier
has been added to the -mm tree. Its filename is
hugetlb-reservations-move-region-tracking-earlier.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: hugetlb reservations: move region tracking earlier
From: Andy Whitcroft <apw@xxxxxxxxxxxx>
As reported by Adam Litke and Jon Tollefson one of the libhugetlbfs
regression tests triggers a negative overall reservation count. When
this occurs where there is no dynamic pool enabled tests will fail.
Following this email are two patches to address this issue:
hugetlb reservations: move region tracking earlier -- simply moves the
region tracking code earlier so we do not have to supply prototypes, and
hugetlb reservations: fix hugetlb MAP_PRIVATE reservations across vma
splits -- which moves us to tracking the consumed reservation so that
we can correctly calculate the remaining reservations at vma close time.
This stack is against the top of v2.6.25-rc6-mm3, should this solution
prove acceptable it would need slipping underneath Nick's multiple hugepage
size patches and those updated. I have a modified stack prepared for that.
This version incorporates Mel's feedback (both cosmetic, and an allocation
under spinlock issue) and has an improved layout.
Changes in V2:
- commentry updates
- pull allocations out from under hugetlb_lock
- refactor to match shared code layout
- reinstate BUG_ON's
This patch:
Move the region tracking code much earlier so we can use it for page
presence tracking later on. No code is changed, just its location.
Signed-off-by: Andy Whitcroft <apw@xxxxxxxxxxxx>
Acked-by: Mel Gorman <mel@xxxxxxxxx>
Cc: Adam Litke <agl@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxx>
Cc: William Lee Irwin III <wli@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxxxxxxx>
Cc: Jon Tollefson <kniht@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 246 ++++++++++++++++++++++++-------------------------
1 file changed, 125 insertions(+), 121 deletions(-)
diff -puN mm/hugetlb.c~hugetlb-reservations-move-region-tracking-earlier mm/hugetlb.c
--- a/mm/hugetlb.c~hugetlb-reservations-move-region-tracking-earlier
+++ a/mm/hugetlb.c
@@ -47,6 +47,131 @@ static unsigned long __initdata default_
static DEFINE_SPINLOCK(hugetlb_lock);
/*
+ * Region tracking -- allows tracking of reservations and instantiated pages
+ * across the pages in a mapping.
+ */
+struct file_region {
+ struct list_head link;
+ long from;
+ long to;
+};
+
+static long region_add(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg, *trg;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+
+ /* Check for and consume any regions we now overlap with. */
+ nrg = rg;
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ break;
+
+ /* If this area reaches higher then extend our area to
+ * include it completely. If this is not the first area
+ * which we intend to reuse, free it. */
+ if (rg->to > t)
+ t = rg->to;
+ if (rg != nrg) {
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ }
+ nrg->from = f;
+ nrg->to = t;
+ return 0;
+}
+
+static long region_chg(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg;
+ long chg = 0;
+
+ /* Locate the region we are before or in. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* If we are below the current region then a new region is required.
+ * Subtle, allocate a new region at the position but make it zero
+ * size such that we can guarantee to record the reservation. */
+ if (&rg->link == head || t < rg->from) {
+ nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
+ if (!nrg)
+ return -ENOMEM;
+ nrg->from = f;
+ nrg->to = f;
+ INIT_LIST_HEAD(&nrg->link);
+ list_add(&nrg->link, rg->link.prev);
+
+ return t - f;
+ }
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+ chg = t - f;
+
+ /* Check for and consume any regions we now overlap with. */
+ list_for_each_entry(rg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ return chg;
+
+ /* We overlap with this area, if it extends futher than
+ * us then we must extend ourselves. Account for its
+ * existing reservation. */
+ if (rg->to > t) {
+ chg += rg->to - t;
+ t = rg->to;
+ }
+ chg -= rg->to - rg->from;
+ }
+ return chg;
+}
+
+static long region_truncate(struct list_head *head, long end)
+{
+ struct file_region *rg, *trg;
+ long chg = 0;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (end <= rg->to)
+ break;
+ if (&rg->link == head)
+ return 0;
+
+ /* If we are in the middle of a region then adjust it. */
+ if (end > rg->from) {
+ chg = rg->to - end;
+ rg->to = end;
+ rg = list_entry(rg->link.next, typeof(*rg), link);
+ }
+
+ /* Drop any remaining regions. */
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ chg += rg->to - rg->from;
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ return chg;
+}
+
+/*
* Convert the address within this vma to the page offset within
* the mapping, in pagecache page units; huge pages here.
*/
@@ -638,127 +763,6 @@ static void return_unused_surplus_pages(
}
}
-struct file_region {
- struct list_head link;
- long from;
- long to;
-};
-
-static long region_add(struct list_head *head, long f, long t)
-{
- struct file_region *rg, *nrg, *trg;
-
- /* Locate the region we are either in or before. */
- list_for_each_entry(rg, head, link)
- if (f <= rg->to)
- break;
-
- /* Round our left edge to the current segment if it encloses us. */
- if (f > rg->from)
- f = rg->from;
-
- /* Check for and consume any regions we now overlap with. */
- nrg = rg;
- list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
- if (&rg->link == head)
- break;
- if (rg->from > t)
- break;
-
- /* If this area reaches higher then extend our area to
- * include it completely. If this is not the first area
- * which we intend to reuse, free it. */
- if (rg->to > t)
- t = rg->to;
- if (rg != nrg) {
- list_del(&rg->link);
- kfree(rg);
- }
- }
- nrg->from = f;
- nrg->to = t;
- return 0;
-}
-
-static long region_chg(struct list_head *head, long f, long t)
-{
- struct file_region *rg, *nrg;
- long chg = 0;
-
- /* Locate the region we are before or in. */
- list_for_each_entry(rg, head, link)
- if (f <= rg->to)
- break;
-
- /* If we are below the current region then a new region is required.
- * Subtle, allocate a new region at the position but make it zero
- * size such that we can guarantee to record the reservation. */
- if (&rg->link == head || t < rg->from) {
- nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
- if (!nrg)
- return -ENOMEM;
- nrg->from = f;
- nrg->to = f;
- INIT_LIST_HEAD(&nrg->link);
- list_add(&nrg->link, rg->link.prev);
-
- return t - f;
- }
-
- /* Round our left edge to the current segment if it encloses us. */
- if (f > rg->from)
- f = rg->from;
- chg = t - f;
-
- /* Check for and consume any regions we now overlap with. */
- list_for_each_entry(rg, rg->link.prev, link) {
- if (&rg->link == head)
- break;
- if (rg->from > t)
- return chg;
-
- /* We overlap with this area, if it extends futher than
- * us then we must extend ourselves. Account for its
- * existing reservation. */
- if (rg->to > t) {
- chg += rg->to - t;
- t = rg->to;
- }
- chg -= rg->to - rg->from;
- }
- return chg;
-}
-
-static long region_truncate(struct list_head *head, long end)
-{
- struct file_region *rg, *trg;
- long chg = 0;
-
- /* Locate the region we are either in or before. */
- list_for_each_entry(rg, head, link)
- if (end <= rg->to)
- break;
- if (&rg->link == head)
- return 0;
-
- /* If we are in the middle of a region then adjust it. */
- if (end > rg->from) {
- chg = rg->to - end;
- rg->to = end;
- rg = list_entry(rg->link.next, typeof(*rg), link);
- }
-
- /* Drop any remaining regions. */
- list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
- if (&rg->link == head)
- break;
- chg += rg->to - rg->from;
- list_del(&rg->link);
- kfree(rg);
- }
- return chg;
-}
-
/*
* Determine if the huge page at addr within the vma has an associated
* reservation. Where it does not we will need to logically increase
_
Patches currently in -mm which might be from apw@xxxxxxxxxxxx are
mm-add-a-basic-debugging-framework-for-memory-initialisation.patch
mm-add-a-basic-debugging-framework-for-memory-initialisation-fix.patch
mm-verify-the-page-links-and-memory-model.patch
mm-make-defensive-checks-around-pfn-values-registered-for-memory-usage.patch
mm-print-out-the-zonelists-on-request-for-manual-verification.patch
add-a-helper-function-to-test-if-an-object-is-on-the-stack.patch
mm-move-bootmem-descriptors-definition-to-a-single-place.patch
mm-fix-free_all_bootmem_core-alignment-check.patch
mm-normalize-internal-argument-passing-of-bootmem-data.patch
mm-unexport-__alloc_bootmem_core.patch
buddy-clarify-comments-describing-buddy-merge.patch
page-flags-record-page-flag-overlays-explicitly.patch
page-flags-record-page-flag-overlays-explicitly-xen.patch
slub-record-page-flag-overlays-explicitly.patch
slob-record-page-flag-overlays-explicitly.patch
hugetlb-move-hugetlb_acct_memory.patch
hugetlb-reserve-huge-pages-for-reliable-map_private-hugetlbfs-mappings-until-fork.patch
hugetlb-guarantee-that-cow-faults-for-a-process-that-called-mmapmap_private-on-hugetlbfs-will-succeed.patch
hugetlb-guarantee-that-cow-faults-for-a-process-that-called-mmapmap_private-on-hugetlbfs-will-succeed-fix.patch
hugetlb-guarantee-that-cow-faults-for-a-process-that-called-mmapmap_private-on-hugetlbfs-will-succeed-build-fix.patch
huge-page-private-reservation-review-cleanups.patch
huge-page-private-reservation-review-cleanups-fix.patch
mm-record-map_noreserve-status-on-vmas-and-fix-small-page-mprotect-reservations.patch
hugetlb-move-reservation-region-support-earlier.patch
hugetlb-allow-huge-page-mappings-to-be-created-without-reservations.patch
hugetlb-allow-huge-page-mappings-to-be-created-without-reservations-cleanups.patch
hugetlb-reservations-move-region-tracking-earlier.patch
hugetlb-reservations-fix-hugetlb-map_private-reservations-across-vma-splits-v2.patch
memory-hotplugallocate-usemap-on-the-section-with-pgdat-take-4.patch
memory-hotplug-small-fixes-to-bootmem-freeing-for-memory-hotremove.patch
checkpatch-version-020.patch
checkpatch-return-is-not-a-function-parentheses-for-casts-are-ok-too.patch
checkpatch-types-some-types-may-also-be-identifiers.patch
checkpatch-add-a-checkpatch-warning-for-new-uses-of-__initcall.patch
checkpatch-possible-types-__asm__-is-never-a-type.patch
checkpatch-comment-detection-ignore-macro-continuation-when-detecting-associated-comments.patch
checkpatch-types-unary-goto-introduces-unary-context.patch
checkpatch-macros-fix-statement-counting-block-end-detection.patch
checkpatch-trailing-statement-indent-fix-end-of-statement-location.patch
checkpatch-allow-printk-strings-to-exceed-80-characters-to-maintain-their-searchability.patch
checkpatch-switch-report-trailing-statements-on-case-and-default.patch
checkpatch-check-spacing-for-square-brackets.patch
checkpatch-toughen-trailing-if-statement-checks-and-extend-them-to-while-and-for.patch
checkpatch-condition-loop-indent-checks.patch
checkpatch-usb_free_urb-can-take-null.patch
checkpatch-correct-spelling-in-kfree-checks.patch
checkpatch-allow-for-type-modifiers-on-multiple-declarations.patch
checkpatch-improve-type-matcher-debug.patch
checkpatch-possible-modifiers-are-not-being-correctly-matched.patch
checkpatch-macro-complexity-checks-are-meaningless-in-linker-scripts.patch
checkpatch-handle-return-types-of-pointers-to-functions.patch
checkpatch-possible-types-known-modifiers-cannot-be-types.patch
checkpatch-possible-modifiers-handle-multiple-modifiers-and-trailing.patch
x86-implement-pte_special.patch
mm-introduce-get_user_pages_fast.patch
mm-introduce-get_user_pages_fast-fix.patch
mm-introduce-get_user_pages_fast-checkpatch-fixes.patch
x86-lockless-get_user_pages_fast.patch
x86-lockless-get_user_pages_fast-checkpatch-fixes.patch
x86-lockless-get_user_pages_fast-fix.patch
x86-lockless-get_user_pages_fast-fix-2.patch
x86-lockless-get_user_pages_fast-fix-2-fix-fix.patch
x86-lockless-get_user_pages_fast-fix-warning.patch
dio-use-get_user_pages_fast.patch
splice-use-get_user_pages_fast.patch
page-owner-tracking-leak-detector.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
