Date: Wed, 20 Feb 2008 14:28:23 GMT From: Tobias Mohrlueder <mail@tobiasmo.de> To: freebsd-gnats-submit@FreeBSD.org Subject: misc/120884: bktr driver always stores the contigmalloc'ed memory pointers Message-ID: <200802201428.m1KESNdO005033@www.freebsd.org> Resent-Message-ID: <200802201440.m1KEe2D4026782@freefall.freebsd.org>
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>Number: 120884
>Category: misc
>Synopsis: bktr driver always stores the contigmalloc'ed memory pointers
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Feb 20 14:40:02 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator: Tobias Mohrlueder
>Release: RELENG_7
>Organization:
>Environment:
FreeBSD acheron.local.lan 7.0-PRERELEASE FreeBSD 7.0-PRERELEASE #0: Fri Feb 8 19:54:00 CET 2008 tobiasmo@acheron.local.lan:/usr/obj/usr/src/sys/ACHERON i386
>Description:
While building world on my machine, I experienced a problem with the bktr driver module. One contigmalloc() call failed and as a result, the module was left in a defective state. Any further load attempts were futile, because the bktr memory loader cannot be unloaded (and the driver keeps thinking that there already is enough memory allocated).
>From /var/log/messages:
Jan 15 17:01:13 acheron kernel: bktr0: Unable to allocate 3555328 bytes of memory.
bktr_mem.c's sole purpose is to avoid the situation of having to contigmalloc() memory everytime the bktr module is loaded, so maybe this is a known "problem" and the solution is to load the module at boot time.
>How-To-Repeat:
Although not an exact guide how to repeat the problem;
1) Put the machine under load (e.g. make buildworld)
2) kldload bktr
>Fix:
Load the module at boot time.
Or: Maybe the attached patch helps. It looks like a trivial problem, but I am not a seasoned programmer.
Patch attached with submission follows:
--- /usr/src/sys/dev/bktr/bktr_core.c 2005-12-04 11:06:03.000000000 +0100
+++ bktr_core.c 2008-02-19 17:15:01.000000000 +0100
@@ -528,11 +528,17 @@
/* If this is a module, save the current contiguous memory */
#if defined(BKTR_FREEBSD_MODULE)
-bktr_store_address(unit, BKTR_MEM_DMA_PROG, bktr->dma_prog);
-bktr_store_address(unit, BKTR_MEM_ODD_DMA_PROG, bktr->odd_dma_prog);
-bktr_store_address(unit, BKTR_MEM_VBIDATA, bktr->vbidata);
-bktr_store_address(unit, BKTR_MEM_VBIBUFFER, bktr->vbibuffer);
-bktr_store_address(unit, BKTR_MEM_BUF, buf);
+
+ /* Only save when all relevant get_bktr_mem() calls succeeded */
+ if ( bktr->dma_prog != 0 && bktr->odd_dma_prog != 0 &&
+ bktr->vbidata != 0 && bktr->vbibuffer != 0 &&
+ ( BROOKTREE_ALLOC ? buf != 0 : 1 ) ) {
+ bktr_store_address(unit, BKTR_MEM_DMA_PROG, bktr->dma_prog);
+ bktr_store_address(unit, BKTR_MEM_ODD_DMA_PROG, bktr->odd_dma_prog);
+ bktr_store_address(unit, BKTR_MEM_VBIDATA, bktr->vbidata);
+ bktr_store_address(unit, BKTR_MEM_VBIBUFFER, bktr->vbibuffer);
+ bktr_store_address(unit, BKTR_MEM_BUF, buf);
+ }
#endif
>Release-Note:
>Audit-Trail:
>Unformatted:
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