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Krister Johansen 21d25f6a42 dmaengine: iota: ioat_alloc_chan_resources should not perform sleeping allocations.
On a kernel with DEBUG_LOCKS, ioat_free_chan_resources triggers an
in_interrupt() warning.  With PROVE_LOCKING, it reports detecting a
SOFTIRQ-safe to SOFTIRQ-unsafe lock ordering in the same code path.

This is because dma_generic_alloc_coherent() checks if the GFP flags
permit blocking.  It allocates from different subsystems if blocking is
permitted.  The free path knows how to return the memory to the correct
allocator.  If GFP_KERNEL is specified then the alloc and free end up
going through cma_alloc(), which uses mutexes.

Given that ioat_free_chan_resources() can be called in interrupt
context, ioat_alloc_chan_resources() must specify GFP_NOWAIT so that the
allocations do not block and instead use an allocator that uses
spinlocks.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-10 10:41:51 +05:30
arch mm: optimize PageWaiters bit use for unlock_page() 2016-12-29 11:03:15 -08:00
block ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto crypto: testmgr - Use heap buffer for acomp test input 2016-12-27 17:32:11 +08:00
Documentation Documentation/unaligned-memory-access.txt: fix incorrect comparison operator 2016-12-27 13:08:42 -07:00
drivers dmaengine: iota: ioat_alloc_chan_resources should not perform sleeping allocations. 2017-01-10 10:41:51 +05:30
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs ext4: Simplify DAX fault path 2016-12-26 20:29:25 -08:00
include Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2017-01-01 12:27:05 -08:00
init mm: add PageWaiters indicating tasks are waiting for a page bit 2016-12-25 11:54:48 -08:00
ipc ipc/sem: avoid idr tree lookup for interrupted semop 2016-12-14 16:04:08 -08:00
kernel smp/hotplug: Undo tglxs brainfart 2016-12-26 17:30:24 -08:00
lib Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
mm Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2017-01-01 12:27:05 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-27 16:04:37 -08:00
samples Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-23 16:49:12 -08:00
scripts Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-12-22 10:03:52 -08:00
security Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sound ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
tools Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2016-12-25 14:01:28 -08:00
usr initramfs: allow again choice of the embedded initram compression algorithm 2016-12-14 16:04:08 -08:00
virt Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
COPYING
CREDITS CREDITS: Remove outdated address information 2016-12-21 15:21:29 -08:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig kbuild: migrate all arch to the kconfig mainmenu upgrade 2010-09-19 22:54:11 -04:00
MAINTAINERS MAINTAINERS: dmaengine: Update + Hand over the at_hdmac driver to Ludovic 2017-01-03 09:13:05 +05:30
Makefile Linux 4.10-rc2 2017-01-01 14:31:53 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.