From: Christoph Lameter <clameter@sgi.com>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [09/18] Vcompound: GFP_VFALLBACK debugging aid
Date: Wed, 03 Oct 2007 20:59:44 -0700 [thread overview]
Message-ID: <20071004040003.797970826@sgi.com> (raw)
In-Reply-To: 20071004035935.042951211@sgi.com
[-- Attachment #1: vcompound_debugging_aid --]
[-- Type: text/plain, Size: 2107 bytes --]
Virtual fallbacks are rare and thus subtle bugs may creep in if we do not
test the fallbacks. CONFIG_VFALLBACK_ALWAYS makes all GFP_VFALLBACK
allocations fall back to virtual mapping.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
---
lib/Kconfig.debug | 11 +++++++++++
mm/page_alloc.c | 6 ++++++
2 files changed, 17 insertions(+)
Index: linux-2.6/mm/page_alloc.c
===================================================================
--- linux-2.6.orig/mm/page_alloc.c 2007-10-03 18:04:33.000000000 -0700
+++ linux-2.6/mm/page_alloc.c 2007-10-03 18:07:16.000000000 -0700
@@ -1257,6 +1257,12 @@ zonelist_scan:
}
}
+#ifdef CONFIG_VFALLBACK_ALWAYS
+ if ((gfp_mask & __GFP_VFALLBACK) &&
+ system_state == SYSTEM_RUNNING)
+ return alloc_vcompound(gfp_mask, order,
+ zonelist, alloc_flags);
+#endif
page = buffered_rmqueue(zonelist, zone, order, gfp_mask);
if (page)
break;
Index: linux-2.6/lib/Kconfig.debug
===================================================================
--- linux-2.6.orig/lib/Kconfig.debug 2007-10-03 18:04:29.000000000 -0700
+++ linux-2.6/lib/Kconfig.debug 2007-10-03 18:07:16.000000000 -0700
@@ -105,6 +105,17 @@ config DETECT_SOFTLOCKUP
can be detected via the NMI-watchdog, on platforms that
support it.)
+config VFALLBACK_ALWAYS
+ bool "Always fall back to Virtual Compound pages"
+ default y
+ help
+ Virtual compound pages are only allocated if there is no linear
+ memory available. They are a fallback and errors created by the
+ use of virtual mappings instead of linear ones may not surface
+ because of their infrequent use. This option makes every
+ allocation that allows a fallback to a virtual mapping use
+ the virtual mapping. May have a significant performance impact.
+
config SCHED_DEBUG
bool "Collect scheduler debugging info"
depends on DEBUG_KERNEL && PROC_FS
--
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2007-10-04 3:59 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-04 3:59 [00/18] Virtual Compound Page Support V2 Christoph Lameter
2007-10-04 3:59 ` [01/18] vmalloc: clean up page array indexing Christoph Lameter
2007-10-04 3:59 ` [02/18] vunmap: return page array passed on vmap() Christoph Lameter
2007-10-04 3:59 ` [03/18] vmalloc_address(): Determine vmalloc address from page struct Christoph Lameter
2007-10-04 3:59 ` [04/18] Vcompound: Smart up virt_to_head_page() Christoph Lameter
2007-10-04 3:59 ` [05/18] Page flags: Add PageVcompound() Christoph Lameter
2007-10-04 3:59 ` [06/18] Vcompound: Update page address determination Christoph Lameter
2007-10-04 3:59 ` [07/18] Vcompound: Add compound_nth_page() to determine nth base page Christoph Lameter
2007-10-04 3:59 ` [08/18] GFP_VFALLBACK: Allow fallback of compound pages to virtual mappings Christoph Lameter
2007-10-04 3:59 ` Christoph Lameter [this message]
2007-10-04 3:59 ` [10/18] Sparsemem: Use fallback for the memmap Christoph Lameter
2007-10-04 3:59 ` [11/18] Page allocator: Use a higher order allocation for the zone wait table Christoph Lameter
2007-10-04 3:59 ` [12/18] Wait: Allow bit_waitqueue to wait on a bit in a virtual compound page Christoph Lameter
2007-10-04 3:59 ` [13/18] x86_64: Allow fallback for the stack Christoph Lameter
2007-10-04 11:56 ` Andi Kleen
2007-10-04 12:08 ` Peter Zijlstra
2007-10-04 12:25 ` Andi Kleen
2007-10-04 12:30 ` Peter Zijlstra
2007-10-04 17:40 ` Christoph Lameter
2007-10-04 19:20 ` Christoph Lameter
2007-10-04 19:39 ` Rik van Riel
2007-10-04 21:20 ` Christoph Lameter
2007-10-07 7:35 ` Nick Piggin
2007-10-08 17:36 ` Christoph Lameter
2007-10-08 12:55 ` Nick Piggin
2007-10-09 18:39 ` Christoph Lameter
2007-10-09 8:46 ` Nick Piggin
2007-10-10 1:26 ` Christoph Lameter
2007-10-09 9:56 ` Nick Piggin
2007-10-10 3:36 ` where to get ZONE_MOVABLE pathces? Jacky(GuangXiang Lee)
2007-10-10 10:32 ` Mel Gorman
2007-10-06 18:53 ` [13/18] x86_64: Allow fallback for the stack Bill Davidsen
2007-10-04 3:59 ` [14/18] Configure stack size Christoph Lameter
2007-10-04 4:36 ` Arjan van de Ven
2007-10-04 4:43 ` David Miller, Arjan van de Ven
2007-10-04 19:34 ` Christoph Lameter
2007-10-04 9:11 ` Andi Kleen
2007-10-04 19:26 ` Christoph Lameter
2007-10-04 3:59 ` [15/18] Fallback for temporary order 2 allocation Christoph Lameter
2007-10-04 3:59 ` [16/18] Virtual Compound page allocation from interrupt context Christoph Lameter
2007-10-04 3:59 ` [17/18] Virtual compound page freeing in " Christoph Lameter
2007-10-04 3:59 ` [18/18] SLUB: Use fallback for table of callers/freers of a slab cache Christoph Lameter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20071004040003.797970826@sgi.com \
--to=clameter@sgi.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).