The patch titled
Subject: sparc: clarify __GFP_NOFAIL allocation
has been added to the -mm tree. Its filename is
sparc-clarify-__gfp_nofail-allocation.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/sparc-clarify-__gfp_nofail-allocation.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/sparc-clarify-__gfp_nofail-allocation.patch
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------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxx>
Subject: sparc: clarify __GFP_NOFAIL allocation
920c3ed74134 ([SPARC64]: Add basic infrastructure for MD add/remove
notification.) has added __GFP_NOFAIL for the allocation request but it
hasn't mentioned why is this strict requirement really needed. The code
was handling an allocation failure and propagated it properly up the
callchain so it is not clear why it is needed.
Dave has clarified the intention when I tried to remove the flag as not
being necessary:
: It is a serious failure.
:
: If we miss an MDESC update due to this allocation failure, the update
: is not an event which gets retransmitted so we will lose the updated
: machine description forever.
:
: We really need this allocation to succeed.
So add a comment to clarify the nofail flag and get rid of the failure
check because __GFP_NOFAIL allocation doesn't fail.
Signed-off-by: Michal Hocko <mhocko@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Vipul Pandya <vipul@xxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/sparc/kernel/mdesc.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff -puN arch/sparc/kernel/mdesc.c~sparc-clarify-__gfp_nofail-allocation arch/sparc/kernel/mdesc.c
--- a/arch/sparc/kernel/mdesc.c~sparc-clarify-__gfp_nofail-allocation
+++ a/arch/sparc/kernel/mdesc.c
@@ -130,26 +130,26 @@ static struct mdesc_mem_ops memblock_mde
static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size)
{
unsigned int handle_size;
+ struct mdesc_handle *hp;
+ unsigned long addr;
void *base;
handle_size = (sizeof(struct mdesc_handle) -
sizeof(struct mdesc_hdr) +
mdesc_size);
+ /*
+ * Allocation has to succeed because mdesc update would be missed
+ * and such events are not retransmitted.
+ */
base = kmalloc(handle_size + 15, GFP_KERNEL | __GFP_NOFAIL);
- if (base) {
- struct mdesc_handle *hp;
- unsigned long addr;
+ addr = (unsigned long)base;
+ addr = (addr + 15UL) & ~15UL;
+ hp = (struct mdesc_handle *) addr;
- addr = (unsigned long)base;
- addr = (addr + 15UL) & ~15UL;
- hp = (struct mdesc_handle *) addr;
+ mdesc_handle_init(hp, handle_size, base);
- mdesc_handle_init(hp, handle_size, base);
- return hp;
- }
-
- return NULL;
+ return hp;
}
static void mdesc_kfree(struct mdesc_handle *hp)
_
Patches currently in -mm which might be from mhocko@xxxxxxx are
origin.patch
mm-oom-do-not-fail-__gfp_nofail-allocation-if-oom-killer-is-disbaled.patch
mm-memcontrol-update-copyright-notice.patch
mm-cma-release-trigger-fixpatch.patch
mm-hide-per-cpu-lists-in-output-of-show_mem.patch
mm-completely-remove-dumping-per-cpu-lists-from-show_mem.patch
mm-refactor-do_wp_page-extract-the-reuse-case.patch
mm-refactor-do_wp_page-rewrite-the-unlock-flow.patch
mm-refactor-do_wp_page-extract-the-page-copy-flow.patch
mm-refactor-do_wp_page-handling-of-shared-vma-into-a-function.patch
mm-vmscan-fix-the-page-state-calculation-in-too_many_isolated.patch
mm-page_isolation-check-pfn-validity-before-access.patch
mm-support-madvisemadv_free.patch
mm-dont-split-thp-page-when-syscall-is-called.patch
mm-dont-split-thp-page-when-syscall-is-called-fix-2.patch
fork-report-pid-reservation-failure-properly.patch
mm-clarify-__gfp_nofail-deprecation-status.patch
jbd2-revert-must-not-fail-allocation-loops-back-to-gfp_nofail.patch
sparc-clarify-__gfp_nofail-allocation.patch
cxgb4-drop-__gfp_nofail-allocation.patch
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