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* Merge tag 'for-linus-4.3' of git://git.code.sf.net/p/openipmi/linux-ipmiLinus Torvalds2015-09-0811-280/+437
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull IPMI updates from Corey Minyard: "Most of these have been sitting in linux-next for more than a release, particularly commit 0fbcf4af7c83 ("ipmi: Convert the IPMI SI ACPI handling to a platform device") which is probably the most complex patch. That is also the one that changes drivers/acpi/acpi_pnp.c. The change in that file is only removing IPMI from a "special platform devices" list, since I convert it to the standard PNP interface. I posted this one to the ACPI list twice and got no response, and it seems to work well in my testing, so I'm hoping it's good. Hidehiro Kawai posted a set of changes that improves the panic time handling in the IPMI driver. The rest of the changes are minor bug fixes or cleanups and some documentation" * tag 'for-linus-4.3' of git://git.code.sf.net/p/openipmi/linux-ipmi: ipmi:ssif: Add a module parm to specify that SMBus alerts don't work ipmi: add of_device_id in MODULE_DEVICE_TABLE ipmi: Compensate for BMCs that wont set the irq enable bit ipmi: Don't call receive handler in the panic context ipmi: Avoid touching possible corrupted lists in the panic context ipmi: Don't flush messages in sender() in run-to-completion mode ipmi: Factor out message flushing procedure ipmi: Remove unneeded set_run_to_completion call ipmi: Make some data const that was only read ipmi: constify SSIF ACPI device ids ipmi: Delete an unnecessary check before the function call "cleanup_one_si" char:ipmi - Change 1 to true for bool type variables during initialization. impi:Remove unneeded setting of module owner to THIS_MODULE in the platform structure, powernv_ipmi_driver ipmi: Add a comment in how messages are delivered from the lower layer ipmi/powernv: Fix potential invalid pointer dereference ipmi: Convert the IPMI SI ACPI handling to a platform device ipmi: Add device tree bindings information
| * ipmi:ssif: Add a module parm to specify that SMBus alerts don't workCorey Minyard2015-09-031-0/+8
| | | | | | | | | | | | | | They are broken on some platforms, this gives people a chance to work around it until the firmware is fixed. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: add of_device_id in MODULE_DEVICE_TABLEBrijesh Singh2015-09-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | Fix autoloading ipmi modules when using device tree. Signed-off-by: Brijesh Singh <brijeshkumar.singh@amd.com> Moved this change up into the CONFIG_OF section to account for changes to the probing code. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Compensate for BMCs that wont set the irq enable bitCorey Minyard2015-09-031-43/+137
| | | | | | | | | | | | | | | | | | | | | | | | It appears that some BMCs support interrupts but don't support setting the irq enable bits. The interrupts are just always on. Sigh. Add code to compensate. The new code was very similar to another functions, so this also factors out the common code into other functions. Signed-off-by: Corey Minyard <cminyard@mvista.com> Tested-by: Henrik Korkuc <henrik@kirneh.eu>
| * ipmi: Don't call receive handler in the panic contextHidehiro Kawai2015-09-031-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | Received handlers defined as ipmi_recv_hndl member of struct ipmi_user_hndl can take a spinlock. This means that if the kernel panics while holding the lock, a deadlock may happen on the lock while flushing queued messages in the panic context. Calling the receive handler doesn't make much meanings in the panic context, simply skip it to avoid possible deadlocks. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Avoid touching possible corrupted lists in the panic contextHidehiro Kawai2015-09-031-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When processing queued messages in the panic context, IPMI driver tries to do it without any locking to avoid deadlocks. However, this means we can touch a corrupted list if the kernel panicked while manipulating the list. Fortunately, current `add-tail and del-from-head' style implementation won't touch the corrupted part, but it is inherently risky. To get rid of the risk, this patch re-initializes the message lists on panic if the related spinlock has already been acquired. As the result, we may lose queued messages, but it's not so painful. Dropping messages on the received message list is also less problematic because no one can respond the received messages. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Fixed a comment typo. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Don't flush messages in sender() in run-to-completion modeHidehiro Kawai2015-09-033-5/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When flushing queued messages in run-to-completion mode, smi_event_handler() is recursively called. flush_messages() smi_event_handler() handle_transaction_done() deliver_recv_msg() ipmi_smi_msg_received() smi_recv_tasklet() sender() flush_messages() smi_event_handler() ... The depth of the recursive call depends on the number of queued messages, so it can cause a stack overflow if many messages have been queued. To solve this problem, this patch removes flush_messages() from sender()@ipmi_si_intf.c. Instead, add flush_messages() to caller side of sender() if needed. Additionally, to implement this, add new handler flush_messages to struct ipmi_smi_handlers. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Fixed up a comment and some spacing issues. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Factor out message flushing procedureHidehiro Kawai2015-09-031-21/+18
| | | | | | | | | | | | | | | | Factor out message flushing procedure which is used in run-to-completion mode. This patch doesn't change the logic. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Remove unneeded set_run_to_completion callHidehiro Kawai2015-09-031-2/+0
| | | | | | | | | | | | | | | | | | send_panic_events() calls intf->handlers->set_run_to_completion(), but it has already been done in the caller function panic_event(). Remove it from send_panic_events(). Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Make some data const that was only readCorey Minyard2015-09-037-37/+40
| | | | | | | | | | | | | | Several data structures were only used for reading, so make them const. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: constify SSIF ACPI device idsMathias Krause2015-09-031-1/+1
| | | | | | | | | | | | | | | | Constify the ACPI device ID array, it doesn't need to be writable at runtime. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Delete an unnecessary check before the function call "cleanup_one_si"Markus Elfring2015-09-031-3/+1
| | | | | | | | | | | | | | | | | | | | The cleanup_one_si() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * char:ipmi - Change 1 to true for bool type variables during initialization.Shailendra Verma2015-09-032-6/+6
| | | | | | | | | | Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * impi:Remove unneeded setting of module owner to THIS_MODULE in the platform ↵Nicholas Krause2015-09-031-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | structure, powernv_ipmi_driver This removes the no longer required setting of the module owner for the plaform structure,powernv_ipmi_driver to THIS_MODULE as the driver core for ipmi drivers will directly find and set the module owner for this driver. Signed-off-by: Nicholas Krause <xerofoify@gmail.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Add a comment in how messages are delivered from the lower layerCorey Minyard2015-09-031-0/+4
| | | | | | | | | | | | To avoid confusion in the future. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi/powernv: Fix potential invalid pointer dereferenceNeelesh Gupta2015-09-031-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the OPAL call to receive the ipmi message fails, then we free up the smi message and return. But, the driver still holds the reference to old smi message in the 'cur_msg' which can potentially be accessed later and freed again leading to kernel oops. To fix it up, The kernel driver should reset the 'cur_msg' and send reply to the user in addition to freeing the message. Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Fixed a checkpatch warning dealing with an else after a return. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Convert the IPMI SI ACPI handling to a platform deviceCorey Minyard2015-09-032-165/+157
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The IPMI SI driver was using direct PNP, but that was not really ideal because the IPMI device is a platform device. There was some special handling in the acpi_pnp.c code for making this work, but that was breaking ACPI handling for the IPMI SSIF driver. So without this patch there were significant issues getting the SSIF driver to work with ACPI. So use a platform device for ACPI detection and remove the entry from acpi_pnp.c. Signed-off-by: Corey Minyard <cminyard@mvista.com>
| * ipmi: Add device tree bindings informationCorey Minyard2015-09-031-0/+25
| | | | | | | | Signed-off-by: Corey Minyard <cminyard@mvista.com>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2015-09-0899-1569/+2784
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge second patch-bomb from Andrew Morton: "Almost all of the rest of MM. There was an unusually large amount of MM material this time" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (141 commits) zpool: remove no-op module init/exit mm: zbud: constify the zbud_ops mm: zpool: constify the zpool_ops mm: swap: zswap: maybe_preload & refactoring zram: unify error reporting zsmalloc: remove null check from destroy_handle_cache() zsmalloc: do not take class lock in zs_shrinker_count() zsmalloc: use class->pages_per_zspage zsmalloc: consider ZS_ALMOST_FULL as migrate source zsmalloc: partial page ordering within a fullness_list zsmalloc: use shrinker to trigger auto-compaction zsmalloc: account the number of compacted pages zsmalloc/zram: introduce zs_pool_stats api zsmalloc: cosmetic compaction code adjustments zsmalloc: introduce zs_can_compact() function zsmalloc: always keep per-class stats zsmalloc: drop unused variable `nr_to_migrate' mm/memblock.c: fix comment in __next_mem_range() mm/page_alloc.c: fix type information of memoryless node memory-hotplug: fix comments in zone_spanned_pages_in_node() and zone_spanned_pages_in_node() ...
| * | zpool: remove no-op module init/exitDan Streetman2015-09-081-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove zpool_init() and zpool_exit(); they do nothing other than print "loaded" and "unloaded". Signed-off-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm: zbud: constify the zbud_opsKrzysztof Kozlowski2015-09-082-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The structure zbud_ops is not modified so make the pointer to it a pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm: zpool: constify the zpool_opsKrzysztof Kozlowski2015-09-085-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The structure zpool_ops is not modified so make the pointer to it a pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm: swap: zswap: maybe_preload & refactoringDmitry Safonov2015-09-083-78/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zswap_get_swap_cache_page and read_swap_cache_async have pretty much the same code with only significant difference in return value and usage of swap_readpage. I a helper __read_swap_cache_async() with the common code. Behavior change: now zswap_get_swap_cache_page will use radix_tree_maybe_preload instead radix_tree_preload. Looks like, this wasn't changed only by the reason of code duplication. Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zram: unify error reportingSergey Senozhatsky2015-09-081-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make zram syslog error reporting more consistent. We have random error levels in some places. For example, critical errors like "Error allocating memory for compressed page" and "Unable to allocate temp memory" are reported as KERN_INFO messages. a) Reassign error levels Error messages that directly affect zram functionality -- pr_err(): Error allocating zram address table Error creating memory pool Decompression failed! err=%d, page=%u Unable to allocate temp memory Compression failed! err=%d Error allocating memory for compressed page: %u, size=%zu Cannot initialise %s compressing backend Error allocating disk queue for device %d Error allocating disk structure for device %d Error creating sysfs group for device %d Unable to register zram-control class Unable to get major number Messages that do not affect functionality, but user must be warned (because sysfs attrs will be removed in this particular case) -- pr_warn(): %d (%s) Attribute %s (and others) will be removed. %s Messages that do not affect functionality and mostly are informative -- pr_info(): Cannot change max compression streams Can't change algorithm for initialized device Cannot change disksize for initialized device Added device: %s Removed device: %s b) Update sysfs_create_group() error message First, it lacks a trailing new line; add it. Second, every error message in zram_add() has a "for device %d" part, which makes errors more informative. Add missing part to "Error creating sysfs group" message. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: remove null check from destroy_handle_cache()Sergey Senozhatsky2015-09-081-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can pass a NULL cache pointer to kmem_cache_destroy(), because it NULL-checks its argument now. Remove redundant test from destroy_handle_cache(). Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: do not take class lock in zs_shrinker_count()Sergey Senozhatsky2015-09-081-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can avoid taking class ->lock around zs_can_compact() in zs_shrinker_count(), because the number that we return back is outdated in general case, by design. We have different sources that are able to change class's state right after we return from zs_can_compact() -- ongoing I/O operations, manually triggered compaction, or two of them happening simultaneously. We re-do this calculations during compaction on a per class basis anyway. zs_unregister_shrinker() will not return until we have an active shrinker, so classes won't unexpectedly disappear while zs_shrinker_count() iterates them. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: use class->pages_per_zspageMinchan Kim2015-09-081-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need to recalcurate pages_per_zspage in runtime. Just use class->pages_per_zspage to avoid unnecessary runtime overhead. Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: consider ZS_ALMOST_FULL as migrate sourceMinchan Kim2015-09-081-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no reason to prevent select ZS_ALMOST_FULL as migration source if we cannot find source from ZS_ALMOST_EMPTY. With this patch, zs_can_compact will return more exact result. Signed-off-by: Minchan Kim <minchan.kim@lge.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: partial page ordering within a fullness_listSergey Senozhatsky2015-09-081-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY} pages. Put a page with higher ->inuse count first within its ->fullness_list, which will give us better chances to fill up this page with new objects (find_get_zspage() return ->fullness_list head for new object allocation), so some zspages will become ZS_ALMOST_FULL/ZS_FULL quicker. It performs a trivial and cheap ->inuse compare which does not slow down zsmalloc and in the worst case keeps the list pages in no particular order. A more expensive solution could sort fullness_list by ->inuse count. [minchan@kernel.org: code adjustments] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: use shrinker to trigger auto-compactionSergey Senozhatsky2015-09-081-0/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Perform automatic pool compaction by a shrinker when system is getting tight on memory. User-space has a very little knowledge regarding zsmalloc fragmentation and basically has no mechanism to tell whether compaction will result in any memory gain. Another issue is that user space is not always aware of the fact that system is getting tight on memory. Which leads to very uncomfortable scenarios when user space may start issuing compaction 'randomly' or from crontab (for example). Fragmentation is not always necessarily bad, allocated and unused objects, after all, may be filled with the data later, w/o the need of allocating a new zspage. On the other hand, we obviously don't want to waste memory when the system needs it. Compaction now has a relatively quick pool scan so we are able to estimate the number of pages that will be freed easily, which makes it possible to call this function from a shrinker->count_objects() callback. We also abort compaction as soon as we detect that we can't free any pages any more, preventing wasteful objects migrations. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: account the number of compacted pagesSergey Senozhatsky2015-09-084-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compaction returns back to zram the number of migrated objects, which is quite uninformative -- we have objects of different sizes so user space cannot obtain any valuable data from that number. Change compaction to operate in terms of pages and return back to compaction issuer the number of pages that were freed during compaction. So from now on we will export more meaningful value in zram<id>/mm_stat -- the number of freed (compacted) pages. This requires: (a) a rename of `num_migrated' to 'pages_compacted' (b) a internal API change -- return first_page's fullness_group from putback_zspage(), so we know when putback_zspage() did free_zspage(). It helps us to account compaction stats correctly. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc/zram: introduce zs_pool_stats apiSergey Senozhatsky2015-09-084-21/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | `zs_compact_control' accounts the number of migrated objects but it has a limited lifespan -- we lose it as soon as zs_compaction() returns back to zram. It worked fine, because (a) zram had it's own counter of migrated objects and (b) only zram could trigger compaction. However, this does not work for automatic pool compaction (not issued by zram). To account objects migrated during auto-compaction (issued by the shrinker) we need to store this number in zs_pool. Define a new `struct zs_pool_stats' structure to keep zs_pool's stats there. It provides only `num_migrated', as of this writing, but it surely can be extended. A new zsmalloc zs_pool_stats() symbol exports zs_pool's stats back to caller. Use zs_pool_stats() in zram and remove `num_migrated' from zram_stats. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: cosmetic compaction code adjustmentsSergey Senozhatsky2015-09-081-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change zs_object_copy() argument order to be (DST, SRC) rather than (SRC, DST). copy/move functions usually have (to, from) arguments order. Rename alloc_target_page() to isolate_target_page(). This function doesn't allocate anything, it isolates target page, pretty much like isolate_source_page(). Tweak __zs_compact() comment. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: introduce zs_can_compact() functionSergey Senozhatsky2015-09-081-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function checks if class compaction will free any pages. Rephrasing -- do we have enough unused objects to form at least one ZS_EMPTY page and free it. It aborts compaction if class compaction will not result in any (further) savings. EXAMPLE (this debug output is not part of this patch set): - class size - number of allocated objects - number of used objects - max objects per zspage - pages per zspage - estimated number of pages that will be freed [..] class-512 objs:544 inuse:540 maxobj-per-zspage:8 pages-per-zspage:1 zspages-to-free:0 ... class-512 compaction is useless. break class-496 objs:660 inuse:570 maxobj-per-zspage:33 pages-per-zspage:4 zspages-to-free:2 class-496 objs:627 inuse:570 maxobj-per-zspage:33 pages-per-zspage:4 zspages-to-free:1 class-496 objs:594 inuse:570 maxobj-per-zspage:33 pages-per-zspage:4 zspages-to-free:0 ... class-496 compaction is useless. break class-448 objs:657 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:4 class-448 objs:648 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:3 class-448 objs:639 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:2 class-448 objs:630 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:1 class-448 objs:621 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:0 ... class-448 compaction is useless. break class-432 objs:728 inuse:685 maxobj-per-zspage:28 pages-per-zspage:3 zspages-to-free:1 class-432 objs:700 inuse:685 maxobj-per-zspage:28 pages-per-zspage:3 zspages-to-free:0 ... class-432 compaction is useless. break class-416 objs:819 inuse:705 maxobj-per-zspage:39 pages-per-zspage:4 zspages-to-free:2 class-416 objs:780 inuse:705 maxobj-per-zspage:39 pages-per-zspage:4 zspages-to-free:1 class-416 objs:741 inuse:705 maxobj-per-zspage:39 pages-per-zspage:4 zspages-to-free:0 ... class-416 compaction is useless. break class-400 objs:690 inuse:674 maxobj-per-zspage:10 pages-per-zspage:1 zspages-to-free:1 class-400 objs:680 inuse:674 maxobj-per-zspage:10 pages-per-zspage:1 zspages-to-free:0 ... class-400 compaction is useless. break class-384 objs:736 inuse:709 maxobj-per-zspage:32 pages-per-zspage:3 zspages-to-free:0 ... class-384 compaction is useless. break [..] Every "compaction is useless" indicates that we saved CPU cycles. class-512 has 544 object allocated 540 objects used 8 objects per-page Even if we have a ALMOST_EMPTY zspage, we still don't have enough room to migrate all of its objects and free this zspage; so compaction will not make a lot of sense, it's better to just leave it as is. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: always keep per-class statsSergey Senozhatsky2015-09-081-32/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always account per-class `zs_size_stat' stats. This data will help us make better decisions during compaction. We are especially interested in OBJ_ALLOCATED and OBJ_USED, which can tell us if class compaction will result in any memory gain. For instance, we know the number of allocated objects in the class, the number of objects being used (so we also know how many objects are not used) and the number of objects per-page. So we can ensure if we have enough unused objects to form at least one ZS_EMPTY zspage during compaction. We calculate this value on per-class basis so we can calculate a total number of zspages that can be released. Which is exactly what a shrinker wants to know. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | zsmalloc: drop unused variable `nr_to_migrate'Sergey Senozhatsky2015-09-081-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset tweaks compaction and makes it possible to trigger pool compaction automatically when system is getting low on memory. zsmalloc in some cases can suffer from a notable fragmentation and compaction can release some considerable amount of memory. The problem here is that currently we fully rely on user space to perform compaction when needed. However, performing zsmalloc compaction is not always an obvious thing to do. For example, suppose we have a `idle' fragmented (compaction was never performed) zram device and system is getting low on memory due to some 3rd party user processes (gcc LTO, or firefox, etc.). It's quite unlikely that user space will issue zpool compaction in this case. Besides, user space cannot tell for sure how badly pool is fragmented; however, this info is known to zsmalloc and, hence, to a shrinker. This patch (of 7): __zs_compact() does not use `nr_to_migrate', drop it. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm/memblock.c: fix comment in __next_mem_range()Alexander Kuleshov2015-09-081-1/+1
| | | | | | | | | | | | | | | | | | Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm/page_alloc.c: fix type information of memoryless nodeZhen Lei2015-09-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For a memoryless node, the output of get_pfn_range_for_nid are all zero. It will display mem from 0 to -1. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.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>
| * | memory-hotplug: fix comments in zone_spanned_pages_in_node() and ↵Xishi Qiu2015-09-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zone_spanned_pages_in_node() When hot adding a node from add_memory(), we will add memblock first, so the node is not empty. But when called from cpu_up(), the node should be empty. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Taku Izumi <izumi.taku@jp.fujitsu.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/page_alloc.c: change sysctl_lower_zone_reserve_ratio to ↵Yaowei Bai2015-09-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysctl_lowmem_reserve_ratio in comments We use sysctl_lowmem_reserve_ratio rather than sysctl_lower_zone_reserve_ratio to determine how aggressive the kernel is in defending lowmem from the possibility of being captured into pinned user memory. To avoid misleading, correct it in some comments. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Acked-by: Michal Hocko <mhocko@suse.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/page_alloc.c: fix a misleading commentYaowei Bai2015-09-082-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment says that the per-cpu batchsize and zone watermarks are determined by present_pages which is definitely wrong, they are both calculated from managed_pages. Fix it. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm/mmap.c:insert_vm_struct(): check for failure before setting valuesChen Gang2015-09-081-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no point in initializing vma->vm_pgoff if the insertion attempt will be failing anyway. Run the checks before performing the initialization. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm/khugepaged: allow interruption of allocation sleep againPetr Mladek2015-09-081-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 1dfb059b9438 ("thp: reduce khugepaged freezing latency") fixed khugepaged to do not block a system suspend. But the result is that it could not get interrupted before the given timeout because the condition for the wait event is "false". This patch puts back the original approach but it uses freezable_schedule_timeout_interruptible() instead of schedule_timeout_interruptible(). It does the right thing. I am pretty sure that the freezable variant was not used in the original fix only because it was not available at that time. The regression has been there for ages. It was not critical. It just did the allocation throttling a little bit more aggressively. I found this problem when converting the kthread to kthread worker API and trying to understand the code. This bug is thought to have minimal userspace-visible impact. Somebody could set a high alloc_sleep value by mistake, and then try to fix it back, but khugepaged would keep sleeping until the high value expires. Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm/memblock.c: fiy typos in commentsAlexander Kuleshov2015-09-081-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | s/succees/success/ Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm/compaction: correct to flush migrated pages if pageblock skip happensJoonsoo Kim2015-09-082-15/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We cache isolate_start_pfn before entering isolate_migratepages(). If pageblock is skipped in isolate_migratepages() due to whatever reason, cc->migrate_pfn can be far from isolate_start_pfn hence we flush pages that were freed. For example, the following scenario can be possible: - assume order-9 compaction, pageblock order is 9 - start_isolate_pfn is 0x200 - isolate_migratepages() - skip a number of pageblocks - start to isolate from pfn 0x600 - cc->migrate_pfn = 0x620 - return - last_migrated_pfn is set to 0x200 - check flushing condition - current_block_start is set to 0x600 - last_migrated_pfn < current_block_start then do useless flush This wrong flush would not help the performance and success rate so this patch tries to fix it. One simple way to know the exact position where we start to isolate migratable pages is that we cache it in isolate_migratepages() before entering actual isolation. This patch implements that and fixes the problem. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm: use numa_mem_id() in alloc_pages_node()Vlastimil Babka2015-09-081-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_pages_node() might fail when called with NUMA_NO_NODE and __GFP_THISNODE on a CPU belonging to a memoryless node. To make the local-node fallback more robust and prevent such situations, use numa_mem_id(), which was introduced for similar scenarios in the slab context. Suggested-by: Christoph Lameter <cl@linux.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Christoph Lameter <cl@linux.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm: unify checks in alloc_pages_node() and __alloc_pages_node()Vlastimil Babka2015-09-081-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Perform the same debug checks in alloc_pages_node() as are done in __alloc_pages_node(), by making the former function a wrapper of the latter one. In addition to better diagnostics in DEBUG_VM builds for situations which have been already fatal (e.g. out-of-bounds node id), there are two visible changes for potential existing buggy callers of alloc_pages_node(): - calling alloc_pages_node() with any negative nid (e.g. due to arithmetic overflow) was treated as passing NUMA_NO_NODE and fallback to local node was applied. This will now be fatal. - calling alloc_pages_node() with an offline node will now be checked for DEBUG_VM builds. Since it's not fatal if the node has been previously online, and this patch may expose some existing buggy callers, change the VM_BUG_ON in __alloc_pages_node() to VM_WARN_ON. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm: rename alloc_pages_exact_node() to __alloc_pages_node()Vlastimil Babka2015-09-0818-37/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_pages_exact_node() was introduced in commit 6484eb3e2a81 ("page allocator: do not check NUMA node ID when the caller knows the node is valid") as an optimized variant of alloc_pages_node(), that doesn't fallback to current node for nid == NUMA_NO_NODE. Unfortunately the name of the function can easily suggest that the allocation is restricted to the given node and fails otherwise. In truth, the node is only preferred, unless __GFP_THISNODE is passed among the gfp flags. The misleading name has lead to mistakes in the past, see for example commits 5265047ac301 ("mm, thp: really limit transparent hugepage allocation to local node") and b360edb43f8e ("mm, mempolicy: migrate_to_node should only migrate to node"). Another issue with the name is that there's a family of alloc_pages_exact*() functions where 'exact' means exact size (instead of page order), which leads to more confusion. To prevent further mistakes, this patch effectively renames alloc_pages_exact_node() to __alloc_pages_node() to better convey that it's an optimized variant of alloc_pages_node() not intended for general usage. Both functions get described in comments. It has been also considered to really provide a convenience function for allocations restricted to a node, but the major opinion seems to be that __GFP_THISNODE already provides that functionality and we shouldn't duplicate the API needlessly. The number of users would be small anyway. Existing callers of alloc_pages_exact_node() are simply converted to call __alloc_pages_node(), with the exception of sba_alloc_coherent() which open-codes the check for NUMA_NO_NODE, so it is converted to use alloc_pages_node() instead. This means it no longer performs some VM_BUG_ON checks, and since the current check for nid in alloc_pages_node() uses a 'nid < 0' comparison (which includes NUMA_NO_NODE), it may hide wrong values which would be previously exposed. Both differences will be rectified by the next patch. To sum up, this patch makes no functional changes, except temporarily hiding potentially buggy callers. Restricting the checks in alloc_pages_node() is left for the next patch which can in turn expose more existing buggy callers. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Robin Holt <robinmholt@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Cliff Whickman <cpw@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm, vmscan: unlock page while waiting on writebackHugh Dickins2015-09-081-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is merely a politeness: I've not found that shrink_page_list() leads to deadlock with the page it holds locked across wait_on_page_writeback(); but nevertheless, why hold others off by keeping the page locked there? And while we're at it: remove the mistaken "not " from the commentary on this Case 3 (and a distracting blank line from Case 2, if I may). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | list_lru: don't call list_lru_from_kmem if the list_head is emptyJeff Layton2015-09-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the list_head is empty then we'll have called list_lru_from_kmem for nothing. Move that call inside of the list_empty if block. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>