linux-toradex.git/mm/dmapool.c, branch v3.0.65 Linux kernel for Apalis and Colibri modules mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls 2012-12-17T18:49:02+00:00 Marek Szyprowski m.szyprowski@samsung.com 2012-11-07T14:37:07+00:00 b9f21c252726e320c3878d9206571e2178cafd10 commit 387870f2d6d679746020fa8e25ef786ff338dc98 upstream. dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag, regardless the flags provided by the caller. This causes excessive pruning of emergency memory pools without any good reason. Additionaly, on ARM architecture any driver which is using dmapools will sooner or later trigger the following error: "ERROR: 256 KiB atomic DMA coherent pool is too small! Please increase it with coherent_pool= kernel parameter!". Increasing the coherent pool size usually doesn't help much and only delays such error, because all GFP_ATOMIC DMA allocations are always served from the special, very limited memory pool. This patch changes the dmapool code to correctly use gfp flags provided by the dmapool caller. Reported-by: Soeren Moch <smoch@web.de> Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Soeren Moch <smoch@web.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 387870f2d6d679746020fa8e25ef786ff338dc98 upstream.

dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag,
regardless the flags provided by the caller. This causes excessive
pruning of emergency memory pools without any good reason. Additionaly,
on ARM architecture any driver which is using dmapools will sooner or
later  trigger the following error:
"ERROR: 256 KiB atomic DMA coherent pool is too small!
Please increase it with coherent_pool= kernel parameter!".
Increasing the coherent pool size usually doesn't help much and only
delays such error, because all GFP_ATOMIC DMA allocations are always
served from the special, very limited memory pool.

This patch changes the dmapool code to correctly use gfp flags provided
by the dmapool caller.

Reported-by: Soeren Moch <smoch@web.de>
Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Soeren Moch <smoch@web.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/dmapool.c: use TASK_UNINTERRUPTIBLE in dma_pool_alloc() 2011-01-14T01:32:48+00:00 Andrew Morton akpm@linux-foundation.org 2011-01-13T23:47:25+00:00 684265d4a30f133162f06ddb2e5010608e60e4bb As it stands this code will degenerate into a busy-wait if the calling task has signal_pending(). Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
As it stands this code will degenerate into a busy-wait if the calling task
has signal_pending().

Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/dmapool.c: take lock only once in dma_pool_free() 2011-01-14T01:32:48+00:00 Rolf Eike Beer eike-kernel@sf-tec.de 2011-01-13T23:47:24+00:00 84bc227d7fde049a568cd58a5610613feedc0dff dma_pool_free() scans for the page to free in the pool list holding the pool lock. Then it releases the lock basically to acquire it immediately again. Modify the code to only take the lock once. This will do some additional loops and computations with the lock held in if memory debugging is activated. If it is not activated the only new operations with this lock is one if and one substraction. Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
dma_pool_free() scans for the page to free in the pool list holding the
pool lock.  Then it releases the lock basically to acquire it immediately
again.  Modify the code to only take the lock once.

This will do some additional loops and computations with the lock held in
if memory debugging is activated.  If it is not activated the only new
operations with this lock is one if and one substraction.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: add a might_sleep_if() to dma_pool_alloc() 2010-10-26T23:52:08+00:00 Dima Zavin dima@android.com 2010-10-26T21:21:54+00:00 ea05c8444e451f1cfbf78c68733e717ad7b8602b Buggy drivers (e.g. fsl_udc) could call dma_pool_alloc from atomic context with GFP_KERNEL. In most instances, the first pool_alloc_page call would succeed and the sleeping functions would never be called. This allowed the buggy drivers to slip through the cracks. Add a might_sleep_if() checking for __GFP_WAIT in flags. Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Buggy drivers (e.g.  fsl_udc) could call dma_pool_alloc from atomic
context with GFP_KERNEL.  In most instances, the first pool_alloc_page
call would succeed and the sleeping functions would never be called.  This
allowed the buggy drivers to slip through the cracks.

Add a might_sleep_if() checking for __GFP_WAIT in flags.

Signed-off-by: Dima Zavin <dima@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dmapools: protect page_list walk in show_pools() 2009-07-01T01:56:00+00:00 Thomas Gleixner tglx@linutronix.de 2009-06-30T18:41:25+00:00 c49568235dd7b4a2ffad63aa950562f4ffb9455f show_pools() walks the page_list of a pool w/o protection against the list modifications in alloc/free. Take pool->lock to avoid stomping into nirvana. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
show_pools() walks the page_list of a pool w/o protection against the list
modifications in alloc/free.  Take pool->lock to avoid stomping into
nirvana.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too 2008-04-28T15:58:20+00:00 Andi Kleen ak@suse.de 2008-04-28T09:12:37+00:00 b5ee5befa75e33e55d34584ad10286c5005cb1de Previously it was only enabled for CONFIG_DEBUG_SLAB. Not hooked into the slub runtime debug configuration, so you currently only get it with CONFIG_SLUB_DEBUG_ON, not plain CONFIG_SLUB_DEBUG Acked-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Previously it was only enabled for CONFIG_DEBUG_SLAB.

Not hooked into the slub runtime debug configuration, so you currently only
get it with CONFIG_SLUB_DEBUG_ON, not plain CONFIG_SLUB_DEBUG

Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pool: Improve memory usage for devices which can't cross boundaries 2007-12-04T15:39:58+00:00 Matthew Wilcox matthew@wil.cx 2007-12-03T19:16:24+00:00 e34f44b3517fe545f7fd45a8c2f6ee1e5e4432d3 The previous implementation simply refused to allocate more than a boundary's worth of data from an entire page. Some users didn't know this, so specified things like SMP_CACHE_BYTES, not realising the horrible waste of memory that this was. It's fairly easy to correct this problem, just by ensuring we don't cross a boundary within a page. This even helps drivers like EHCI (which can't cross a 4k boundary) on machines with larger page sizes. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net> 
The previous implementation simply refused to allocate more than a
boundary's worth of data from an entire page.  Some users didn't know
this, so specified things like SMP_CACHE_BYTES, not realising the
horrible waste of memory that this was.  It's fairly easy to correct
this problem, just by ensuring we don't cross a boundary within a page.
This even helps drivers like EHCI (which can't cross a 4k boundary)
on machines with larger page sizes.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Change dmapool free block management 2007-12-04T15:39:57+00:00 Matthew Wilcox matthew@wil.cx 2007-12-03T19:08:28+00:00 a35a3455142976e3fffdf27027f3082cbaba6e8c Use a list of free blocks within a page instead of using a bitmap. Update documentation to reflect this. As well as being a slight reduction in memory allocation, locked ops and lines of code, it speeds up a transaction processing benchmark by 0.4%. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> 
Use a list of free blocks within a page instead of using a bitmap.
Update documentation to reflect this.  As well as being a slight
reduction in memory allocation, locked ops and lines of code, it speeds
up a transaction processing benchmark by 0.4%.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
dmapool: Tidy up includes and add comments 2007-12-04T15:39:57+00:00 Matthew Wilcox matthew@wil.cx 2007-12-03T17:16:57+00:00 6182a0943af2235756836ed7e021fa22b93ec68b We were missing a copyright statement and license, so add GPLv2, David Brownell's copyright and my copyright. The asm/io.h include was superfluous, but we were missing a few other necessary includes. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> 
We were missing a copyright statement and license, so add GPLv2, David
Brownell's copyright and my copyright.

The asm/io.h include was superfluous, but we were missing a few other
necessary includes.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
dmapool: Validate parameters to dma_pool_create 2007-12-04T15:39:56+00:00 Matthew Wilcox matthew@wil.cx 2007-12-03T17:10:24+00:00 399154be2dcb6a58dbde9682162c38113cf3e40b Check that 'align' is a power of two, like the API specifies. Align 'size' to 'align' correctly -- the current code has an off-by-one. The ALIGN macro in kernel.h doesn't. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net> 
Check that 'align' is a power of two, like the API specifies.
Align 'size' to 'align' correctly -- the current code has an off-by-one.
The ALIGN macro in kernel.h doesn't.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: David S. Miller <davem@davemloft.net>