- 16 Oct, 2020 40 commits
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Tobias Jordan authored
Whether crc32_be needs a lookup table is chosen based on CRC_LE_BITS. Obviously, the _be function should be governed by the _BE_ define. This probably never pops up as it's hard to come up with a configuration where CRC_BE_BITS isn't the same as CRC_LE_BITS and as nobody is using bitwise CRC anyway. Fixes: 46c5801e ("crc32: bolt on crc32c") Signed-off-by: Tobias Jordan <kernel@cdqe.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lkml.kernel.org/r/20200923182122.GA3338@agrajag.zerfleddert.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dan Carpenter authored
This is supposed to return false on failure, not a negative error code. Fixes: 170e38548b81 ("mm/hmm/test: use after free in dmirror_allocate_chunk()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Dan Williams <dan.j.williams@intel.com> Link: https://lkml.kernel.org/r/20201010200812.GA1886610@mwandaSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andy Shevchenko authored
Add a macro to test if entry is pointing to the head of the list which is useful in cases like: list_for_each_entry(pos, &head, member) { if (cond) break; } if (list_entry_is_head(pos, &head, member)) return -ERRNO; that allows to avoid additional variable to be added to track if loop has not been stopped in the middle. While here, convert list_for_each_entry*() family of macros to use a new one. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com> Link: https://lkml.kernel.org/r/20200929134342.51489-1-andriy.shevchenko@linux.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
Use helper macro abs() to simplify the "x >= t || x <= -t" cmp. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200927122746.5964-1-linmiaohe@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Christophe JAILLET authored
'sgl' is zeroed a few lines below in 'sg_init_table()'. There is no need to clear it twice. Remove the redundant initialization. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200920071544.368841-1-christophe.jaillet@wanadoo.frSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Stephen Boyd authored
These two functions are deprecated. Users should call ida_alloc() or ida_free() respectively instead. Add documentation to this effect until the macro can be removed. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Tri Vo <trong@android.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Link: https://lkml.kernel.org/r/20200910055246.2297797-2-swboyd@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Stephen Boyd authored
The documentation for these functions indicates that callers don't need to hold a lock while calling them, but that documentation is only in one place under "IDA Usage". Let's state the same information on each IDA function so that it's clear what the calling context requires. Furthermore, let's document ida_simple_get() with the same information so that callers know how this API works. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tri Vo <trong@android.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Link: https://lkml.kernel.org/r/20200910055246.2297797-1-swboyd@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Fix typo/spello of "functions". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/8df15173-a6df-9426-7cad-a2d279bf1170@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040520.1999-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040514.26136-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "be". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040508.26086-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040455.25995-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "the". Fix spelling of "excess". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040449.25946-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "how". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040436.25852-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040430.25807-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop the repeated word "an". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200823040424.25760-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jarkko Sakkinen authored
Use @kernel.org address as the main communications end point. Update the corresponding M-entries and .mailmap (for git shortlog translation). Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Rob Herring <robh@kernel.org> Link: https://lkml.kernel.org/r/20201015142710.8371-1-jarkko.sakkinen@linux.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
MAINTAINERS files generally have no specific maintainer but are updated by individuals for subsystems all over the source tree. Exclude MAINTAINERS file(s) from --git-fallback searches so the unlucky individuals that update the files the most are not shown by default. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Rob Herring <robh@kernel.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Link: https://lkml.kernel.org/r/2bacb0a9c06fbb6d56a43bf930e808c74243c908.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
It's somewhat common for me to ask get_maintainer to tell me who maintains a patch file rather than the files modified by the patch. Emit a warning if using get_maintainer.pl -f <patchfile> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/f63229c051567041819f25e76f49d83c6e4c0f71.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Fix kernel-doc notation to use the documented Returns: syntax and place the function description for acct_process() on the first line where it should be. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Link: https://lkml.kernel.org/r/b4c33e5d-98e8-0c47-77b6-ac1859f94d7f@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Fix multiple occurrences of duplicated words in kernel/. Fix one typo/spello on the same line as a duplicate word. Change one instance of "the the" to "that the". Otherwise just drop one of the repeated words. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Liao Pingfang authored
Replace do_brk with do_brk_flags in comment of prctl_set_mm_map(), since do_brk was removed in following commit. Fixes: bb177a73 ("mm: do not bug_on on incorrect length in __mm_populate()") Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/1600650751-43127-1-git-send-email-wang.yi59@zte.com.cnSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andy Shevchenko authored
kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt to start cleaning it up by splitting out min()/max() et al. helpers. At the same time convert users in header and lib folder to use new header. Though for time being include new header back to kernel.h to avoid twisted indirected includes for other existing users. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20200910164152.GA1891694@smile.fi.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Randy Dunlap authored
Drop duplicated words {the, that} in comments. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joel Becker <jlbec@evilplan.org> Cc: Christoph Hellwig <hch@lst.de> Link: https://lkml.kernel.org/r/20200811021826.25032-1-rdunlap@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
The current page_order() can only be called on pages in the buddy allocator. For compound pages, you have to use compound_order(). This is confusing and led to a bug, so rename page_order() to buddy_order(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20201001152259.14932-2-willy@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mike Rapoport authored
The early_pfn_valid() macro is defined but it is never used. Remove it. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lkml.kernel.org/r/20200923162915.26935-1-rppt@kernel.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
In commit 1da177e4 ("Linux-2.6.12-rc2"), the helper put_write_access() came with the atomic_dec operation of the i_writecount field. But it forgot to use this helper in __vma_link_file() and dup_mmap(). Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200924115235.5111-1-linmiaohe@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Xiaofei Tan authored
Fix following warnings caused by mismatch bewteen function parameters and comments. mm/workingset.c:228: warning: Function parameter or member 'lruvec' not described in 'workingset_age_nonresident' mm/workingset.c:228: warning: Excess function parameter 'memcg' description in 'workingset_age_nonresident' Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/1600485913-11192-1-git-send-email-tanxiaofei@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Chen Tao authored
Correct one function name "get_partials" with "get_partial". Update the old struct name of list3 with kmem_cache_node. Signed-off-by: Chen Tao <chentao3@hotmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lkml.kernel.org/r/Message-ID: Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
Fix some broken comments including typo, grammar error and wrong function name. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200913095456.54873-1-linmiaohe@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Yu Zhao authored
Signed-off-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alex Shi <alex.shi@linux.alibaba.com> Link: http://lkml.kernel.org/r/20200831175042.3527153-2-yuzhao@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ira Weiny authored
The #endif at the end of the file matches up with the '#if defined(HASHED_PAGE_VIRTUAL)' on line 374. Not the CONFIG_HIGHMEM #if earlier. Fix comments on both of the #endif's to indicate the correct end of blocks for each. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lkml.kernel.org/r/20200819184635.112579-1-ira.weiny@intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Wei Yang authored
list_for_each_entry_safe() guarantees that we will never stumble over the list head; "&page->lru != list" will always evaluate to true. Let's simplify. [david@redhat.com: Changelog refinements] Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: http://lkml.kernel.org/r/20200818084448.33969-1-richard.weiyang@linux.alibaba.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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YueHaibing authored
Remove duplicate header which is included twice. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/20200818114323.58156-1-yuehaibing@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Douglas Anderson authored
If we fail to decompress in zram it's a pretty serious problem. We were entrusted to be able to decompress the old data but we failed. Either we've got some crazy bug in the compression code or we've got memory corruption. At the moment, when this happens the log looks like this: ERR kernel: [ 1833.099861] zram: Decompression failed! err=-22, page=336112 ERR kernel: [ 1833.099881] zram: Decompression failed! err=-22, page=336112 ALERT kernel: [ 1833.099886] Read-error on swap-device (253:0:2688896) It is true that we have an "ALERT" level log in there, but (at least to me) it feels like even this isn't enough to impart the seriousness of this error. Let's convert to a WARN_ON. Note that WARN_ON is automatically "unlikely" so we can simply replace the old annotation with the new one. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Link: https://lkml.kernel.org/r/20200917174059.1.If09c882545dbe432268f7a67a4d4cfcb6caace4f@changeidSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand authored
As we no longer shuffle via generic_online_page() and when undoing isolation, we can simplify the comment. We now effectively shuffle only once (properly) when onlining new memory. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-6-david@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand authored
__free_pages_core() is used when exposing fresh memory to the buddy during system boot and when onlining memory in generic_online_page(). generic_online_page() is used in two cases: 1. Direct memory onlining in online_pages(). 2. Deferred memory onlining in memory-ballooning-like mechanisms (HyperV balloon and virtio-mem), when parts of a section are kept fake-offline to be fake-onlined later on. In 1, we already place pages to the tail of the freelist. Pages will be freed to MIGRATE_ISOLATE lists first and moved to the tail of the freelists via undo_isolate_page_range(). In 2, we currently don't implement a proper rule. In case of virtio-mem, where we currently always online MAX_ORDER - 1 pages, the pages will be placed to the HEAD of the freelist - undesireable. While the hyper-v balloon calls generic_online_page() with single pages, usually it will call it on successive single pages in a larger block. The pages are fresh, so place them to the tail of the freelist and avoid the PCP. In __free_pages_core(), remove the now superflouos call to set_page_refcounted() and add a comment regarding page initialization and the refcount. Note: In 2. we currently don't shuffle. If ever relevant (page shuffling is usually of limited use in virtualized environments), we might want to shuffle after a sequence of generic_online_page() calls in the relevant callers. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@kernel.org> Cc: Scott Cheloha <cheloha@linux.ibm.com> Link: https://lkml.kernel.org/r/20201005121534.15649-5-david@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand authored
Whenever we move pages between freelists via move_to_free_list()/ move_freepages_block(), we don't actually touch the pages: 1. Page isolation doesn't actually touch the pages, it simply isolates pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist. When undoing isolation, we move the pages back to the target list. 2. Page stealing (steal_suitable_fallback()) moves free pages directly between lists without touching them. 3. reserve_highatomic_pageblock()/unreserve_highatomic_pageblock() moves free pages directly between freelists without touching them. We already place pages to the tail of the freelists when undoing isolation via __putback_isolated_page(), let's do it in any case (e.g., if order <= pageblock_order) and document the behavior. To simplify, let's move the pages to the tail for all move_to_free_list()/move_freepages_block() users. In 2., the target list is empty, so there should be no change. In 3., we might observe a change, however, highatomic is more concerned about allocations succeeding than cache hotness - if we ever realize this change degrades a workload, we can special-case this instance and add a proper comment. This change results in all pages getting onlined via online_pages() to be placed to the tail of the freelist. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-4-david@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand authored
__putback_isolated_page() already documents that pages will be placed to the tail of the freelist - this is, however, not the case for "order >= MAX_ORDER - 2" (see buddy_merge_likely()) - which should be the case for all existing users. This change affects two users: - free page reporting - page isolation, when undoing the isolation (including memory onlining). This behavior is desirable for pages that haven't really been touched lately, so exactly the two users that don't actually read/write page content, but rather move untouched pages. The new behavior is especially desirable for memory onlining, where we allow allocation of newly onlined pages via undo_isolate_page_range() in online_pages(). Right now, we always place them to the head of the freelist, resulting in undesireable behavior: Assume we add individual memory chunks via add_memory() and online them right away to the NORMAL zone. We create a dependency chain of unmovable allocations e.g., via the memmap. The memmap of the next chunk will be placed onto previous chunks - if the last block cannot get offlined+removed, all dependent ones cannot get offlined+removed. While this can already be observed with individual DIMMs, it's more of an issue for virtio-mem (and I suspect also ppc DLPAR). Document that this should only be used for optimizations, and no code should rely on this behavior for correction (if the order of the freelists ever changes). We won't care about page shuffling: memory onlining already properly shuffles after onlining. free page reporting doesn't care about physically contiguous ranges, and there are already cases where page isolation will simply move (physically close) free pages to (currently) the head of the freelists via move_freepages_block() instead of shuffling. If this becomes ever relevant, we should shuffle the whole zone when undoing isolation of larger ranges, and after free_contig_range(). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-3-david@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand authored
Patch series "mm: place pages to the freelist tail when onlining and undoing isolation", v2. When adding separate memory blocks via add_memory*() and onlining them immediately, the metadata (especially the memmap) of the next block will be placed onto one of the just added+onlined block. This creates a chain of unmovable allocations: If the last memory block cannot get offlined+removed() so will all dependent ones. We directly have unmovable allocations all over the place. This can be observed quite easily using virtio-mem, however, it can also be observed when using DIMMs. The freshly onlined pages will usually be placed to the head of the freelists, meaning they will be allocated next, turning the just-added memory usually immediately un-removable. The fresh pages are cold, prefering to allocate others (that might be hot) also feels to be the natural thing to do. It also applies to the hyper-v balloon xen-balloon, and ppc64 dlpar: when adding separate, successive memory blocks, each memory block will have unmovable allocations on them - for example gigantic pages will fail to allocate. While the ZONE_NORMAL doesn't provide any guarantees that memory can get offlined+removed again (any kind of fragmentation with unmovable allocations is possible), there are many scenarios (hotplugging a lot of memory, running workload, hotunplug some memory/as much as possible) where we can offline+remove quite a lot with this patchset. a) To visualize the problem, a very simple example: Start a VM with 4GB and 8GB of virtio-mem memory: [root@localhost ~]# lsmem RANGE SIZE STATE REMOVABLE BLOCK 0x0000000000000000-0x00000000bfffffff 3G online yes 0-23 0x0000000100000000-0x000000033fffffff 9G online yes 32-103 Memory block size: 128M Total online memory: 12G Total offline memory: 0B Then try to unplug as much as possible using virtio-mem. Observe which memory blocks are still around. Without this patch set: [root@localhost ~]# lsmem RANGE SIZE STATE REMOVABLE BLOCK 0x0000000000000000-0x00000000bfffffff 3G online yes 0-23 0x0000000100000000-0x000000013fffffff 1G online yes 32-39 0x0000000148000000-0x000000014fffffff 128M online yes 41 0x0000000158000000-0x000000015fffffff 128M online yes 43 0x0000000168000000-0x000000016fffffff 128M online yes 45 0x0000000178000000-0x000000017fffffff 128M online yes 47 0x0000000188000000-0x0000000197ffffff 256M online yes 49-50 0x00000001a0000000-0x00000001a7ffffff 128M online yes 52 0x00000001b0000000-0x00000001b7ffffff 128M online yes 54 0x00000001c0000000-0x00000001c7ffffff 128M online yes 56 0x00000001d0000000-0x00000001d7ffffff 128M online yes 58 0x00000001e0000000-0x00000001e7ffffff 128M online yes 60 0x00000001f0000000-0x00000001f7ffffff 128M online yes 62 0x0000000200000000-0x0000000207ffffff 128M online yes 64 0x0000000210000000-0x0000000217ffffff 128M online yes 66 0x0000000220000000-0x0000000227ffffff 128M online yes 68 0x0000000230000000-0x0000000237ffffff 128M online yes 70 0x0000000240000000-0x0000000247ffffff 128M online yes 72 0x0000000250000000-0x0000000257ffffff 128M online yes 74 0x0000000260000000-0x0000000267ffffff 128M online yes 76 0x0000000270000000-0x0000000277ffffff 128M online yes 78 0x0000000280000000-0x0000000287ffffff 128M online yes 80 0x0000000290000000-0x0000000297ffffff 128M online yes 82 0x00000002a0000000-0x00000002a7ffffff 128M online yes 84 0x00000002b0000000-0x00000002b7ffffff 128M online yes 86 0x00000002c0000000-0x00000002c7ffffff 128M online yes 88 0x00000002d0000000-0x00000002d7ffffff 128M online yes 90 0x00000002e0000000-0x00000002e7ffffff 128M online yes 92 0x00000002f0000000-0x00000002f7ffffff 128M online yes 94 0x0000000300000000-0x0000000307ffffff 128M online yes 96 0x0000000310000000-0x0000000317ffffff 128M online yes 98 0x0000000320000000-0x0000000327ffffff 128M online yes 100 0x0000000330000000-0x000000033fffffff 256M online yes 102-103 Memory block size: 128M Total online memory: 8.1G Total offline memory: 0B With this patch set: [root@localhost ~]# lsmem RANGE SIZE STATE REMOVABLE BLOCK 0x0000000000000000-0x00000000bfffffff 3G online yes 0-23 0x0000000100000000-0x000000013fffffff 1G online yes 32-39 Memory block size: 128M Total online memory: 4G Total offline memory: 0B All memory can get unplugged, all memory block can get removed. Of course, no workload ran and the system was basically idle, but it highlights the issue - the fairly deterministic chain of unmovable allocations. When a huge page for the 2MB memmap is needed, a just-onlined 4MB page will be split. The remaining 2MB page will be used for the memmap of the next memory block. So one memory block will hold the memmap of the two following memory blocks. Finally the pages of the last-onlined memory block will get used for the next bigger allocations - if any allocation is unmovable, all dependent memory blocks cannot get unplugged and removed until that allocation is gone. Note that with bigger memory blocks (e.g., 256MB), *all* memory blocks are dependent and none can get unplugged again! b) Experiment with memory intensive workload I performed an experiment with an older version of this patch set (before we used undo_isolate_page_range() in online_pages(): Hotplug 56GB to a VM with an initial 4GB, onlining all memory to ZONE_NORMAL right from the kernel when adding it. I then run various memory intensive workloads that consume most system memory for a total of 45 minutes. Once finished, I try to unplug as much memory as possible. With this change, I am able to remove via virtio-mem (adding individual 128MB memory blocks) 413 out of 448 added memory blocks. Via individual (256MB) DIMMs 380 out of 448 added memory blocks. (I don't have any numbers without this patchset, but looking at the above example, it's at most half of the 448 memory blocks for virtio-mem, and most probably none for DIMMs). Again, there are workloads that might behave very differently due to the nature of ZONE_NORMAL. This change also affects (besides memory onlining): - Other users of undo_isolate_page_range(): Pages are always placed to the tail. -- When memory offlining fails -- When memory isolation fails after having isolated some pageblocks -- When alloc_contig_range() either succeeds or fails - Other users of __putback_isolated_page(): Pages are always placed to the tail. -- Free page reporting - Other users of __free_pages_core() -- AFAIKs, any memory that is getting exposed to the buddy during boot. IIUC we will now usually allocate memory from lower addresses within a zone first (especially during boot). - Other users of generic_online_page() -- Hyper-V balloon This patch (of 5): Let's prepare for additional flags and avoid long parameter lists of bools. Follow-up patches will also make use of the flags in __free_pages_ok(). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-1-david@redhat.com Link: https://lkml.kernel.org/r/20201005121534.15649-2-david@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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