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* xfs: cleanup xfs_file_aio_writeChristoph Hellwig2012-01-171-45/+37
| | | | | | | | | | | | With all the size field updates out of the way xfs_file_aio_write can be further simplified by pushing all iolock handling into xfs_file_dio_aio_write and xfs_file_buffered_aio_write and using the generic generic_write_sync helper for synchronous writes. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: always return with the iolock held from xfs_file_aio_write_checksChristoph Hellwig2012-01-171-3/+4
| | | | | | | | | | While xfs_iunlock is fine with 0 lockflags the calling conventions are much cleaner if xfs_file_aio_write_checks never returns without the iolock held. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: remove the i_new_size field in struct xfs_inodeChristoph Hellwig2012-01-175-92/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that we use the VFS i_size field throughout XFS there is no need for the i_new_size field any more given that the VFS i_size field gets updated in ->write_end before unlocking the page, and thus is always uptodate when writeback could see a page. Removing i_new_size also has the advantage that we will never have to trim back di_size during a failed buffered write, given that it never gets updated past i_size. Note that currently the generic direct I/O code only updates i_size after calling our end_io handler, which requires a small workaround to make sure di_size actually makes it to disk. I hope to fix this properly in the generic code. A downside is that we lose the support for parallel non-overlapping O_DIRECT appending writes that recently was added. I don't think keeping the complex and fragile i_new_size infrastructure for this is a good tradeoff - if we really care about parallel appending writers we should investigate turning the iolock into a range lock, which would also allow for parallel non-overlapping buffered writers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: remove the i_size field in struct xfs_inodeChristoph Hellwig2012-01-1712-82/+56
| | | | | | | | | | | | | | | | | | | | | | | | | There is no fundamental need to keep an in-memory inode size copy in the XFS inode. We already have the on-disk value in the dinode, and the separate in-memory copy that we need for regular files only in the XFS inode. Remove the xfs_inode i_size field and change the XFS_ISIZE macro to use the VFS inode i_size field for regular files. Switch code that was directly accessing the i_size field in the xfs_inode to XFS_ISIZE, or in cases where we are limited to regular files direct access of the VFS inode i_size field. This also allows dropping some fairly complicated code in the write path which dealt with keeping the xfs_inode i_size uptodate with the VFS i_size that is getting updated inside ->write_end. Note that we do not bother resetting the VFS i_size when truncating a file that gets freed to zero as there is no point in doing so because the VFS inode is no longer in use at this point. Just relax the assert in xfs_ifree to only check the on-disk size instead. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: replace i_pin_wait with a bit waitqueueChristoph Hellwig2012-01-174-9/+24
| | | | | | | | | | | | | Replace i_pin_wait, which is only used during synchronous inode flushing with a bit waitqueue. This trades off a much smaller inode against slightly slower wakeup performance, and saves 12 (32-bit) or 20 (64-bit) bytes in the XFS inode. Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: replace i_flock with a sleeping bitlockChristoph Hellwig2012-01-176-46/+76
| | | | | | | | | | | | | | | | | | | | We almost never block on i_flock, the exception is synchronous inode flushing. Instead of bloating the inode with a 16/24-byte completion that we abuse as a semaphore just implement it as a bitlock that uses a bit waitqueue for the rare sleeping path. This primarily is a tradeoff between a much smaller inode and a faster non-blocking path vs faster wakeups, and we are much better off with the former. A small downside is that we will lose lockdep checking for i_flock, but given that it's always taken inside the ilock that should be acceptable. Note that for example the inode writeback locking is implemented in a very similar way. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: make i_flags an unsigned longChristoph Hellwig2012-01-171-1/+1
| | | | | | | | | | | | | | To be used for bit wakeup i_flags needs to be an unsigned long or we'll run into trouble on big endian systems. Because of the 1-byte i_update field right after it this actually causes a fairly large size increase on its own (4 or 8 bytes), but that increase will be more than offset by the next two patches. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: remove the if_ext_max field in struct xfs_iforkChristoph Hellwig2012-01-178-115/+81
| | | | | | | | | | | | | | We spent a lot of effort to maintain this field, but it always equals to the fork size divided by the constant size of an extent. The prime use of it is to assert that the two stay in sync. Just divide the fork size by the extent size in the few places that we actually use it and remove the overhead of maintaining it. Also introduce a few helpers to consolidate the places where we actually care about the value. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: remove the unused dm_attrs structureChristoph Hellwig2012-01-131-7/+0
| | | | | | | | | | .. and the just as dead bhv_desc forward declaration while we're at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: cleanup xfs_iomap_eof_align_last_fsbChristoph Hellwig2012-01-131-18/+18
| | | | | | | | | | Replace the nasty if, else if, elseif condition with more natural C flow that expressed the logic we want here better. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
* xfs: remove xfs_itruncate_dataChristoph Hellwig2012-01-137-142/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This wrapper isn't overly useful, not to say rather confusing. Around the call to xfs_itruncate_extents it does: - add tracing - add a few asserts in debug builds - conditionally update the inode size in two places - log the inode Both the tracing and the inode logging can be moved to xfs_itruncate_extents as they are useful for the attribute fork as well - in fact the attr code already does an equivalent xfs_trans_log_inode call just after calling xfs_itruncate_extents. The conditional size updates are a mess, and there was no reason to do them in two places anyway, as the first one was conditional on the inode having extents - but without extents we xfs_itruncate_extents would be a no-op and the placement wouldn't matter anyway. Instead move the size assignments and the asserts that make sense to the callers that want it. As a side effect of this clean up xfs_setattr_size by introducing variables for the old and new inode size, and moving the size updates into a common place. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
* Merge branch 'akpm' (aka "Andrew's patch-bomb, take two")Linus Torvalds2012-01-12100-1562/+2589
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrew explains: - various misc stuff - Most of the rest of MM: memcg, threaded hugepages, others. - cpumask - kexec - kdump - some direct-io performance tweaking - radix-tree optimisations - new selftests code A note on this: often people will develop a new userspace-visible feature and will develop userspace code to exercise/test that feature. Then they merge the patch and the selftest code dies. Sometimes we paste it into the changelog. Sometimes the code gets thrown into Documentation/(!). This saddens me. So this patch creates a bare-bones framework which will henceforth allow me to ask people to include their test apps in the kernel tree so we can keep them alive. Then when people enhance or fix the feature, I can ask them to update the test app too. The infrastruture is terribly trivial at present - let's see how it evolves. - checkpoint/restart feature work. A note on this: this is a project by various mad Russians to perform c/r mainly from userspace, with various oddball helper code added into the kernel where the need is demonstrated. So rather than some large central lump of code, what we have is little bits and pieces popping up in various places which either expose something new or which permit something which is normally kernel-private to be modified. The overall project is an ongoing thing. I've judged that the size and scope of the thing means that we're more likely to be successful with it if we integrate the support into mainline piecemeal rather than allowing it all to develop out-of-tree. However I'm less confident than the developers that it will all eventually work! So what I'm asking them to do is to wrap each piece of new code inside CONFIG_CHECKPOINT_RESTORE. So if it all eventually comes to tears and the project as a whole fails, it should be a simple matter to go through and delete all trace of it. This lot pretty much wraps up the -rc1 merge for me. * akpm: (96 commits) unlzo: fix input buffer free ramoops: update parameters only after successful init ramoops: fix use of rounddown_pow_of_two() c/r: prctl: add PR_SET_MM codes to set up mm_struct entries c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4 c/r: introduce CHECKPOINT_RESTORE symbol selftests: new x86 breakpoints selftest selftests: new very basic kernel selftests directory radix_tree: take radix_tree_path off stack radix_tree: remove radix_tree_indirect_to_ptr() dio: optimize cache misses in the submission path vfs: cache request_queue in struct block_device fs/direct-io.c: calculate fs_count correctly in get_more_blocks() drivers/parport/parport_pc.c: fix warnings panic: don't print redundant backtraces on oops sysctl: add the kernel.ns_last_pid control kdump: add udev events for memory online/offline include/linux/crash_dump.h needs elf.h kdump: fix crash_kexec()/smp_send_stop() race in panic() kdump: crashk_res init check for /sys/kernel/kexec_crash_size ...
| * unlzo: fix input buffer freeSascha Hauer2012-01-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | unlzo modifies the pointer to in_buf, so we have to free the original buffer, not the modified pointer. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Cc: Lasse Collin <lasse.collin@tukaani.org> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * ramoops: update parameters only after successful initKees Cook2012-01-121-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | If a platform device exists on the system, but ramoops fails to attach to it, the module parameters are overridden before ramoops can fall back and try to use passed module parameters. Move update to end of init routine. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Sergiu Iordache <sergiu@chromium.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * ramoops: fix use of rounddown_pow_of_two()Marco Stornelli2012-01-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | The return value of rounddown_pow_of_two wasn't evaluated, so the operation was a no-op. Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * c/r: prctl: add PR_SET_MM codes to set up mm_struct entriesCyrill Gorcunov2012-01-122-0/+133
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we restore a task we need to set up text, data and data heap sizes from userspace to the values a task had at checkpoint time. This patch adds auxilary prctl codes for that. While most of them have a statistical nature (their values are involved into calculation of /proc/<pid>/statm output) the start_brk and brk values are used to compute an allowed size of program data segment expansion. Which means an arbitrary changes of this values might be dangerous operation. So to restrict access the following requirements applied to prctl calls: - The process has to have CAP_SYS_ADMIN capability granted. - For all opcodes except start_brk/brk members an appropriate VMA area must exist and should fit certain VMA flags, such as: - code segment must be executable but not writable; - data segment must not be executable. start_brk/brk values must not intersect with data segment and must not exceed RLIMIT_DATA resource limit. Still the main guard is CAP_SYS_ADMIN capability check. Note the kernel should be compiled with CONFIG_CHECKPOINT_RESTORE support otherwise these prctl calls will return -EINVAL. [akpm@linux-foundation.org: cache current->mm in a local, saving 200 bytes text] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4Cyrill Gorcunov2012-01-122-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mm->start_code/end_code, mm->start_data/end_data, mm->start_brk are involved into calculation of program text/data segment sizes (which might be seen in /proc/<pid>/statm) and into brk() call final address. For restore we need to know all these values. While mm->start_code/end_code already present in /proc/$pid/stat, the rest members are not, so this patch brings them in. The restore procedure of these members is addressed in another patch using prctl(). Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * c/r: introduce CHECKPOINT_RESTORE symbolCyrill Gorcunov2012-01-121-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For checkpoint/restore we need auxilary features being compiled into the kernel, such as additional prctl codes, /proc/<pid>/map_files and etc... but same time these features are not mandatory for a regular kernel so CHECKPOINT_RESTORE config symbol should bring a way to disable them all at once if one wish to get rid of additional functionality. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * selftests: new x86 breakpoints selftestFrederic Weisbecker2012-01-124-2/+416
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bring a first selftest in the relevant directory. This tests several combinations of breakpoints and watchpoints in x86, as well as icebp traps and int3 traps. Given the amount of breakpoint regressions we raised after we merged the generic breakpoint infrastructure, such selftest became necessary and can still serve today as a basis for new patches that touch the do_debug() path. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * selftests: new very basic kernel selftests directoryFrederic Weisbecker2012-01-122-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bring a new kernel selftests directory in tools/testing/selftests. To add a new selftest, create a subdirectory with the sources and a makefile that creates a target named "run_test" then add the subdirectory name to the TARGET var in tools/testing/selftests/Makefile and tools/testing/selftests/run_tests script. This can help centralizing and maintaining any useful selftest that developers usually tend to let rust in peace on some random server. Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * radix_tree: take radix_tree_path off stackHugh Dickins2012-01-121-78/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Down, down in the deepest depths of GFP_NOIO page reclaim, we have shrink_page_list() calling __remove_mapping() calling __delete_from_ swap_cache() or __delete_from_page_cache(). You would not expect those to need much stack, but in fact they call radix_tree_delete(): which declares a 192-byte radix_tree_path array on its stack (to record the node,offsets it visits when descending, in case it needs to ascend to update them). And if any tag is still set [1], that calls radix_tree_tag_clear(), which declares a further such 192-byte radix_tree_path array on the stack. (At least we have interrupts disabled here, so won't then be pushing registers too.) That was probably a good choice when most users were 32-bit (array of half the size), and adding fields to radix_tree_node would have bloated it unnecessarily. But nowadays many are 64-bit, and each radix_tree_node contains a struct rcu_head, which is only used when freeing; whereas the radix_tree_path info is only used for updating the tree (deleting, clearing tags or setting tags if tagged) when a lock must be held, of no interest when accessing the tree locklessly. So add a parent pointer to the radix_tree_node, in union with the rcu_head, and remove all uses of the radix_tree_path. There would be space in that union to save the offset when descending as before (we can argue that a lock must already be held to exclude other users), but recalculating it when ascending is both easy (a constant shift and a constant mask) and uncommon, so it seems better just to do that. Two little optimizations: no need to decrement height when descending, adjusting shift is enough; and once radix_tree_tag_if_tagged() has set tag on a node and its ancestors, it need not ascend from that node again. perf on the radix tree test harness reports radix_tree_insert() as 2% slower (now having to set parent), but radix_tree_delete() 24% faster. Surely that's an exaggeration from rtth's artificially low map shift 3, but forcing it back to 6 still rates radix_tree_delete() 8% faster. [1] Can a pagecache tag (dirty, writeback or towrite) actually still be set at the time of radix_tree_delete()? Perhaps not if the filesystem is well-behaved. But although I've not tracked any stack overflow down to this cause, I have observed a curious case in which a dirty tag is set and left set on tmpfs: page migration's migrate_page_copy() happens to use __set_page_dirty_nobuffers() to set PageDirty on the newpage, and that sets PAGECACHE_TAG_DIRTY as a side-effect - harmless to a filesystem which doesn't use tags, except for this stack depth issue. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Nai Xia <nai.xia@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * radix_tree: remove radix_tree_indirect_to_ptr()Xiao Guangrong2012-01-121-3/+0
| | | | | | | | | | | | | | | | | | It is not used anymore, remove it Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * dio: optimize cache misses in the submission pathAndi Kleen2012-01-121-9/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some investigation of a transaction processing workload showed that a major consumer of cycles in __blockdev_direct_IO is the cache miss while accessing the block size. This is because it has to walk the chain from block_dev to gendisk to queue. The block size is needed early on to check alignment and sizes. It's only done if the check for the inode block size fails. But the costly block device state is unconditionally fetched. - Reorganize the code to only fetch block dev state when actually needed. Then do a prefetch on the block dev early on in the direct IO path. This is worth it, because there is substantial code run before we actually touch the block dev now. - I also added some unlikelies to make it clear the compiler that block device fetch code is not normally executed. This gave a small, but measurable improvement on a large database benchmark (about 0.3%) [akpm@linux-foundation.org: coding-style fixes] [sfr@canb.auug.org.au: using prefetch requires including prefetch.h] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * vfs: cache request_queue in struct block_deviceAndi Kleen2012-01-122-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes it possible to get from the inode to the request_queue with one less cache miss. Used in followon optimization. The livetime of the pointer is the same as the gendisk. This assumes that the queue will always stay the same in the gendisk while it's visible to block_devices. I think that's safe correct? Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * fs/direct-io.c: calculate fs_count correctly in get_more_blocks()Tao Ma2012-01-121-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In get_more_blocks(), we use dio_count to calcuate fs_count and do some tricky things to increase fs_count if dio_count isn't aligned. But actually it still has some corner cases that can't be coverd. See the following example: dio_write foo -s 1024 -w 4096 (direct write 4096 bytes at offset 1024). The same goes if the offset isn't aligned to fs_blocksize. In this case, the old calculation counts fs_count to be 1, but actually we will write into 2 different blocks (if fs_blocksize=4096). The old code just works, since it will call get_block twice (and may have to allocate and create extents twice for filesystems like ext4). So we'd better call get_block just once with the proper fs_count. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * drivers/parport/parport_pc.c: fix warningsAndrew Morton2012-01-121-2/+2
| | | | | | | | | | | | | | | | | | | | drivers/parport/parport_pc.c: In function '__check_irq': drivers/parport/parport_pc.c:3415: warning: return from incompatible pointer type drivers/parport/parport_pc.c: In function '__check_dma': drivers/parport/parport_pc.c:3417: warning: return from incompatible pointer type Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * panic: don't print redundant backtraces on oopsAndi Kleen2012-01-121-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an oops causes a panic and panic prints another backtrace it's pretty common to have the original oops data be scrolled away on a 80x50 screen. The second backtrace is quite redundant and not needed anyways. So don't print the panic backtrace when oops_in_progress is true. [akpm@linux-foundation.org: add comment] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * sysctl: add the kernel.ns_last_pid controlPavel Emelyanov2012-01-123-1/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sysctl works on the current task's pid namespace, getting and setting its last_pid field. Writing is allowed for CAP_SYS_ADMIN-capable tasks thus making it possible to create a task with desired pid value. This ability is required badly for the checkpoint/restore in userspace. This approach suits all the parties for now. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kdump: add udev events for memory online/offlineMichael Holzheu2012-01-121-3/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently no udev events for memory hotplug "online" and "offline" are generated: # udevadm monitor # echo offline > /sys/devices/system/memory/memory4/state ==> No event When kdump is loaded, kexec detects the current memory configuration and stores it in the pre-allocated ELF core header. Therefore, for kdump it is necessary to reload the kdump kernel with kexec when the memory configuration changes (e.g. for online/offline hotplug memory). In order to do this automatically, udev rules should be used. This kernel patch adds udev events for "online" and "offline". Together with this kernel patch, the following udev rules for online/offline have to be added to "/etc/udev/rules.d/98-kexec.rules": SUBSYSTEM=="memory", ACTION=="online", PROGRAM="/etc/init.d/kdump restart" SUBSYSTEM=="memory", ACTION=="offline", PROGRAM="/etc/init.d/kdump restart" [sfr@canb.auug.org.au: fixups for class to subsystem conversion] Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * include/linux/crash_dump.h needs elf.hFabio Estevam2012-01-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building an ARM target we get the following warnings: CC arch/arm/kernel/setup.o In file included from arch/arm/kernel/setup.c:39: arch/arm/include/asm/elf.h:102:1: warning: "vmcore_elf64_check_arch" redefined In file included from arch/arm/kernel/setup.c:24: include/linux/crash_dump.h:30:1: warning: this is the location of the previous definition Quoting Russell King: "linux/crash_dump.h makes no attempt to include asm/elf.h, but it depends on stuff in asm/elf.h to determine how stuff inside this file is defined at parse time. So, if asm/elf.h is included after linux/crash_dump.h or not at all, you get a different result from the situation where asm/elf.h is included before." So add elf.h header to crash_dump.h to avoid this problem. The original discussion about this can be found at: http://www.spinics.net/lists/arm-kernel/msg154113.html Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: <stable@vger.kernel.org> [3.2.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kdump: fix crash_kexec()/smp_send_stop() race in panic()Michael Holzheu2012-01-121-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When two CPUs call panic at the same time there is a possible race condition that can stop kdump. The first CPU calls crash_kexec() and the second CPU calls smp_send_stop() in panic() before crash_kexec() finished on the first CPU. So the second CPU stops the first CPU and therefore kdump fails: 1st CPU: panic()->crash_kexec()->mutex_trylock(&kexec_mutex)-> do kdump 2nd CPU: panic()->crash_kexec()->kexec_mutex already held by 1st CPU ->smp_send_stop()-> stop 1st CPU (stop kdump) This patch fixes the problem by introducing a spinlock in panic that allows only one CPU to process crash_kexec() and the subsequent panic code. All other CPUs call the weak function panic_smp_self_stop() that stops the CPU itself. This function can be overloaded by architecture code. For example "tile" can use their lower-power "nap" instruction for that. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kdump: crashk_res init check for /sys/kernel/kexec_crash_sizeMichael Holzheu2012-01-121-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently it is possible to set the crash_size via the sysfs /sys/kernel/kexec_crash_size even if no crash kernel memory has been defined with the "crashkernel" parameter. In this case "crashk_res" is not initialized and crashk_res.start = crashk_res.end = 0. Unfortunately resource_size(&crashk_res) returns 1 in this case. This breaks the s390 implementation of crash_(un)map_reserved_pages(). To fix the problem the correct "old_size" is now calculated in crash_shrink_memory(). "old_size is set to "0" if crashk_res is not initialized. With this change crash_shrink_memory() will do nothing, when "crashk_res" is not initialized. It will return "0" for "echo 0 > /sys/kernel/kexec_crash_size" and -EINVAL for "echo [not zero] > /sys/kernel/kexec_crash_size". In addition to that this patch also simplifies the "ret = -EINVAL" vs. "ret = 0" logic as suggested by Simon Horman. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Dave Young <dyoung@redhat.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Reviewed-by: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kdump: add missing RAM resource in crash_shrink_memory()Michael Holzheu2012-01-121-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When shrinking crashkernel memory using /sys/kernel/kexec_crash_size for the newly added memory no RAM resource is created at the moment. Example: $ cat /proc/iomem 00000000-bfffffff : System RAM 00000000-005b7ac3 : Kernel code 005b7ac4-009743bf : Kernel data 009bb000-00a85c33 : Kernel bss c0000000-cfffffff : Crash kernel d0000000-ffffffff : System RAM $ echo 0 > /sys/kernel/kexec_crash_size $ cat /proc/iomem 00000000-bfffffff : System RAM 00000000-005b7ac3 : Kernel code 005b7ac4-009743bf : Kernel data 009bb000-00a85c33 : Kernel bss <<-- here is System RAM missing d0000000-ffffffff : System RAM One result of this bug is that the memory chunk can never be set offline using memory hotplug. With this patch I insert a new "System RAM" resource for the released memory. Then the upper example looks like the following: $ echo 0 > /sys/kernel/kexec_crash_size $ cat /proc/iomem 00000000-bfffffff : System RAM 00000000-005b7ac3 : Kernel code 005b7ac4-009743bf : Kernel data 009bb000-00a85c33 : Kernel bss c0000000-cfffffff : System RAM <<-- new rescoure d0000000-ffffffff : System RAM And now I can set chunk c0000000-cfffffff offline. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kexec: remove KMSG_DUMP_KEXECWANG Cong2012-01-125-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KMSG_DUMP_KEXEC is useless because we already save kernel messages inside /proc/vmcore, and it is unsafe to allow modules to do other stuffs in a crash dump scenario. [akpm@linux-foundation.org: fix powerpc build] Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Reported-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Jarod Wilson <jarod@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * cpumask: update setup_node_to_cpumask_map() commentsWanlong Gao2012-01-122-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | node_to_cpumask() has been replaced by cpumask_of_node(), and wholly removed since commit 29c337a0 ("cpumask: remove obsolete node_to_cpumask now everyone uses cpumask_of_node"). So update the comments for setup_node_to_cpumask_map(). Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/vmalloc.c: eliminate extra loop in pcpu_get_vm_areas error pathKautuk Consul2012-01-121-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If either of the vas or vms arrays are not properly kzalloced, then the code jumps to the err_free label. The err_free label runs a loop to check and free each of the array members of the vas and vms arrays which is not required for this situation as none of the array members have been allocated till this point. Eliminate the extra loop we have to go through by introducing a new label err_free2 and then jumping to it. [akpm@linux-foundation.org: remove now-unneeded tests] Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: rearrange putback_inactive_pagesHugh Dickins2012-01-121-52/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is sometimes confusion between the global putback_lru_pages() in migrate.c and the static putback_lru_pages() in vmscan.c: rename the latter putback_inactive_pages(): it helps shrink_inactive_list() rather as move_active_pages_to_lru() helps shrink_active_list(). Remove unused scan_control arg from putback_inactive_pages() and from update_isolated_counts(). Move clear_active_flags() inside update_isolated_counts(). Move NR_ISOLATED accounting up into shrink_inactive_list() itself, so the balance is clearer. Do the spin_lock_irq() before calling putback_inactive_pages() and spin_unlock_irq() after return from it, so that it better matches update_isolated_counts() and move_active_pages_to_lru(). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: remove isolate_pages()Hugh Dickins2012-01-121-34/+27
| | | | | | | | | | | | | | | | | | | | | | The isolate_pages() level in vmscan.c offers little but indirection: merge it into isolate_lru_pages() as the compiler does, and use the names nr_to_scan and nr_scanned in each case. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: remove del_page_from_lru, add page_off_lruHugh Dickins2012-01-122-8/+11
| | | | | | | | | | | | | | | | | | | | | | del_page_from_lru() repeats del_page_from_lru_list(), also working out which LRU the page was on, clearing the relevant bits. Decouple those functions: remove del_page_from_lru() and add page_off_lru(). Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: enum lru_list lruHugh Dickins2012-01-124-35/+35
| | | | | | | | | | | | | | | | | | Mostly we use "enum lru_list lru": change those few "l"s to "lru"s. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: no blank line after EXPORT_SYMBOL in swap.cHugh Dickins2012-01-121-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | checkpatch rightly protests WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable so fix the five offenders in mm/swap.c. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: fewer underscores in ____pagevec_lru_addHugh Dickins2012-01-122-11/+11
| | | | | | | | | | | | | | | | | | | | | | What's so special about ____pagevec_lru_add() that it needs four leading underscores? Nothing, it just helped to distinguish from __pagevec_lru_add() in 2.6.28 development. Cut two leading underscores. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: take pagevecs off reclaim stackHugh Dickins2012-01-123-39/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru() by lists of pages_to_free: then apply Konstantin Khlebnikov's free_hot_cold_page_list() to them instead of pagevec_release(). Which simplifies the flow (no need to drop and retake lock whenever pagevec fills up) and reduces stale addresses in stack backtraces (which often showed through the pagevecs); but more importantly, removes another 120 bytes from the deepest stacks in page reclaim. Although I've not recently seen an actual stack overflow here with a vanilla kernel, move_active_pages_to_lru() has often featured in deep backtraces. However, free_hot_cold_page_list() does not handle compound pages (nor need it: a Transparent HugePage would have been split by the time it reaches the call in shrink_page_list()), but it is possible for putback_lru_pages() or move_active_pages_to_lru() to be left holding the last reference on a THP, so must exclude the unlikely compound case before putting on pages_to_free. Remove pagevec_strip(), its work now done in move_active_pages_to_lru(). The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c, but that is never on the reclaim path, and cannot be replaced by a list. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * memcg: fix mem_cgroup_print_bad_pageHugh Dickins2012-01-121-16/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If DEBUG_VM, mem_cgroup_print_bad_page() is called whenever bad_page() shows a "Bad page state" message, removes page from circulation, adds a taint and continues. This is at a very low level, often when a spinlock is held (sometimes when page table lock is held, for example). We want to recover from this badness, not make it worse: we must not kmalloc memory here, we must not do a cgroup path lookup via dubious pointers. No doubt that code was useful to debug a particular case at one time, and may be again, but take it out of the mainline kernel. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * memcg: fix split_huge_page_refcounts()Hugh Dickins2012-01-123-30/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch started off as a cleanup: __split_huge_page_refcounts() has to cope with two scenarios, when the hugepage being split is already on LRU, and when it is not; but why does it have to split that accounting across three different sites? Consolidate it in lru_add_page_tail(), handling evictable and unevictable alike, and use standard add_page_to_lru_list() when accounting is needed (when the head is not yet on LRU). But a recent regression in -next, I guess the removal of PageCgroupAcctLRU test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix: under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number, messing up reclaim calculations and causing a freeze at rmdir of cgroup. Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap that count - this has not been the only such incident. Document that lru_add_page_tail() is for Transparent HugePages by #ifdef around it. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: vmscan: check if reclaim should really abort even if compaction_ready() ↵Mel Gorman2012-01-121-10/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is true for one zone If compaction can proceed for a given zone, shrink_zones() does not reclaim any more pages from it. After commit [e0c2327: vmscan: abort reclaim/compaction if compaction can proceed], do_try_to_free_pages() tries to finish as soon as possible once one zone can compact. This was intended to prevent slabs being shrunk unnecessarily but there are side-effects. One is that a small zone that is ready for compaction will abort reclaim even if the chances of successfully allocating a THP from that zone is small. It also means that reclaim can return too early even though sc->nr_to_reclaim pages were not reclaimed. This partially reverts the commit until it is proven that slabs are really being shrunk unnecessarily but preserves the check to return 1 to avoid OOM if reclaim was aborted prematurely. [aarcange@redhat.com: This patch replaces a revert from Andrea] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: vmscan: when reclaiming for compaction, ensure there are sufficient free ↵Mel Gorman2012-01-121-5/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pages available In commit e0887c19 ("vmscan: limit direct reclaim for higher order allocations"), Rik noted that reclaim was too aggressive when THP was enabled. In his initial patch he used the number of free pages to decide if reclaim should abort for compaction. My feedback was that reclaim and compaction should be using the same logic when deciding if reclaim should be aborted. Unfortunately, this had the effect of reducing THP success rates when the workload included something like streaming reads that continually allocated pages. The window during which compaction could run and return a THP was too small. This patch combines Rik's two patches together. compaction_suitable() is still used to decide if reclaim should be aborted to allow compaction is used. However, it will also ensure that there is a reasonable buffer of free pages available. This improves upon the THP allocation success rates but bounds the number of pages that are freed for compaction. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: compaction: introduce sync-light migration for use by compactionMel Gorman2012-01-1211-52/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT mode that avoids writing back pages to backing storage. Async compaction maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is used. This avoids sync compaction stalling for an excessive length of time, particularly when copying files to a USB stick where there might be a large number of dirty pages backed by a filesystem that does not support ->writepages. [aarcange@redhat.com: This patch is heavily based on Andrea's work] [akpm@linux-foundation.org: fix fs/nfs/write.c build] [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: page allocator: do not call direct reclaim for THP allocations while ↵Mel Gorman2012-01-121-10/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | compaction is deferred If compaction is deferred, direct reclaim is used to try to free enough pages for the allocation to succeed. For small high-orders, this has a reasonable chance of success. However, if the caller has specified __GFP_NO_KSWAPD to limit the disruption to the system, it makes more sense to fail the allocation rather than stall the caller in direct reclaim. This patch skips direct reclaim if compaction is deferred and the caller specifies __GFP_NO_KSWAPD. Async compaction only considers a subset of pages so it is possible for compaction to be deferred prematurely and not enter direct reclaim even in cases where it should. To compensate for this, this patch also defers compaction only if sync compaction failed. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: compaction: make isolate_lru_page() filter-aware againMel Gorman2012-01-123-2/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 39deaf85 ("mm: compaction: make isolate_lru_page() filter-aware") noted that compaction does not migrate dirty or writeback pages and that is was meaningless to pick the page and re-add it to the LRU list. This had to be partially reverted because some dirty pages can be migrated by compaction without blocking. This patch updates "mm: compaction: make isolate_lru_page" by skipping over pages that migration has no possibility of migrating to minimise LRU disruption. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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