- 26 9月, 2014 1 次提交
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由 Vladimir Zapolskiy 提交于
Decrement the np_pool device_node refcount, which was incremented on the preceding of_parse_phandle() call. Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Olof Johansson <olof@lixom.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 24 9月, 2014 1 次提交
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由 Tejun Heo 提交于
blk-mq uses percpu_ref for its usage counter which tracks the number of in-flight commands and used to synchronously drain the queue on freeze. percpu_ref shutdown takes measureable wallclock time as it involves a sched RCU grace period. This means that draining a blk-mq takes measureable wallclock time. One would think that this shouldn't matter as queue shutdown should be a rare event which takes place asynchronously w.r.t. userland. Unfortunately, SCSI probing involves synchronously setting up and then tearing down a lot of request_queues back-to-back for non-existent LUNs. This means that SCSI probing may take more than ten seconds when scsi-mq is used. This will be properly fixed by implementing a mechanism to keep q->mq_usage_counter in atomic mode till genhd registration; however, that involves rather big updates to percpu_ref which is difficult to apply late in the devel cycle (v3.17-rc6 at the moment). As a stop-gap measure till the proper fix can be implemented in the next cycle, this patch introduces __percpu_ref_kill_expedited() and makes blk_mq_freeze_queue() use it. This is heavy-handed but should work for testing the experimental SCSI blk-mq implementation. Signed-off-by: NTejun Heo <tj@kernel.org> Reported-by: NChristoph Hellwig <hch@infradead.org> Link: http://lkml.kernel.org/g/20140919113815.GA10791@lst.de Fixes: add703fd ("blk-mq: use percpu_ref for mq usage count") Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Tested-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 20 9月, 2014 1 次提交
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由 Fabian Frederick 提交于
linux/log2.h was included twice. Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 14 9月, 2014 1 次提交
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由 Linus Torvalds 提交于
It used to be an ad-hoc hack defined by the x86 version of <asm/bitops.h> that enabled a couple of library routines to know whether an integer multiply is faster than repeated shifts and additions. This just makes it use the real Kconfig system instead, and makes x86 (which was the only architecture that did this) select the option. NOTE! Even for x86, this really is kind of wrong. If we cared, we would probably not enable this for builds optimized for netburst (P4), where shifts-and-adds are generally faster than multiplies. This patch does *not* change that kind of logic, though, it is purely a syntactic change with no code changes. This was triggered by the fact that we have other places that really want to know "do I want to expand multiples by constants by hand or not", particularly the hash generation code. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 9月, 2014 1 次提交
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由 David Howells 提交于
This fixes CVE-2014-3631. It is possible for an associative array to end up with a shortcut node at the root of the tree if there are more than fan-out leaves in the tree, but they all crowd into the same slot in the lowest level (ie. they all have the same first nibble of their index keys). When assoc_array_gc() returns back up the tree after scanning some leaves, it can fall off of the root and crash because it assumes that the back pointer from a shortcut (after label ascend_old_tree) must point to a normal node - which isn't true of a shortcut node at the root. Should we find we're ascending rootwards over a shortcut, we should check to see if the backpointer is zero - and if it is, we have completed the scan. This particular bug cannot occur if the root node is not a shortcut - ie. if you have fewer than 17 keys in a keyring or if you have at least two keys that sit into separate slots (eg. a keyring and a non keyring). This can be reproduced by: ring=`keyctl newring bar @s` for ((i=1; i<=18; i++)); do last_key=`keyctl newring foo$i $ring`; done keyctl timeout $last_key 2 Doing this: echo 3 >/proc/sys/kernel/keys/gc_delay first will speed things up. If we do fall off of the top of the tree, we get the following oops: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540 PGD dae15067 PUD cfc24067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: xt_nat xt_mark nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_rpfilter ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_ni CPU: 0 PID: 26011 Comm: kworker/0:1 Not tainted 3.14.9-200.fc20.x86_64 #1 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: events key_garbage_collector task: ffff8800918bd580 ti: ffff8800aac14000 task.ti: ffff8800aac14000 RIP: 0010:[<ffffffff8136cea7>] [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540 RSP: 0018:ffff8800aac15d40 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800aaecacc0 RDX: ffff8800daecf440 RSI: 0000000000000001 RDI: ffff8800aadc2bc0 RBP: ffff8800aac15da8 R08: 0000000000000001 R09: 0000000000000003 R10: ffffffff8136ccc7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000070 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 00000000db10d000 CR4: 00000000000006f0 Stack: ffff8800aac15d50 0000000000000011 ffff8800aac15db8 ffffffff812e2a70 ffff880091a00600 0000000000000000 ffff8800aadc2bc3 00000000cd42c987 ffff88003702df20 ffff88003702dfa0 0000000053b65c09 ffff8800aac15fd8 Call Trace: [<ffffffff812e2a70>] ? keyring_detect_cycle_iterator+0x30/0x30 [<ffffffff812e3e75>] keyring_gc+0x75/0x80 [<ffffffff812e1424>] key_garbage_collector+0x154/0x3c0 [<ffffffff810a67b6>] process_one_work+0x176/0x430 [<ffffffff810a744b>] worker_thread+0x11b/0x3a0 [<ffffffff810a7330>] ? rescuer_thread+0x3b0/0x3b0 [<ffffffff810ae1a8>] kthread+0xd8/0xf0 [<ffffffff810ae0d0>] ? insert_kthread_work+0x40/0x40 [<ffffffff816ffb7c>] ret_from_fork+0x7c/0xb0 [<ffffffff810ae0d0>] ? insert_kthread_work+0x40/0x40 Code: 08 4c 8b 22 0f 84 bf 00 00 00 41 83 c7 01 49 83 e4 fc 41 83 ff 0f 4c 89 65 c0 0f 8f 5a fe ff ff 48 8b 45 c0 4d 63 cf 49 83 c1 02 <4e> 8b 34 c8 4d 85 f6 0f 84 be 00 00 00 41 f6 c6 01 0f 84 92 RIP [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540 RSP <ffff8800aac15d40> CR2: 0000000000000018 ---[ end trace 1129028a088c0cbd ]--- Signed-off-by: NDavid Howells <dhowells@redhat.com> Acked-by: NDon Zickus <dzickus@redhat.com> Signed-off-by: NJames Morris <james.l.morris@oracle.com>
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- 03 9月, 2014 2 次提交
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由 Pablo Neira Ayuso 提交于
No need for rht_dereference() from rhashtable_destroy() since the existing callers don't hold the mutex when invoking this function from: 1) Netlink, this is called in case of memory allocation errors in the initialization path, no nl_sk_hash_lock is held. 2) Netfilter, this is called from the rcu callback, no nfnl_lock is held either. I think it's reasonable to assume that the caller has to make sure that no hash resizing may happen before releasing the bucket array. Therefore, the caller should be responsible for releasing this in a safe way, document this to make people aware of it. This resolves a rcu lockdep splat in nft_hash: =============================== [ INFO: suspicious RCU usage. ] 3.16.0+ #178 Not tainted ------------------------------- lib/rhashtable.c:596 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by ksoftirqd/2/18: #0: (rcu_callback){......}, at: [<ffffffff810918fd>] rcu_process_callbacks+0x27e/0x4c7 stack backtrace: CPU: 2 PID: 18 Comm: ksoftirqd/2 Not tainted 3.16.0+ #178 Hardware name: LENOVO 23259H1/23259H1, BIOS G2ET32WW (1.12 ) 05/30/2012 0000000000000001 ffff88011706bb68 ffffffff8143debc 0000000000000000 ffff880117062610 ffff88011706bb98 ffffffff81077515 ffff8800ca041a50 0000000000000004 ffff8800ca386480 ffff8800ca041a00 ffff88011706bbb8 Call Trace: [<ffffffff8143debc>] dump_stack+0x4e/0x68 [<ffffffff81077515>] lockdep_rcu_suspicious+0xfa/0x103 [<ffffffff81228b1b>] rhashtable_destroy+0x46/0x52 [<ffffffffa06f21a7>] nft_hash_destroy+0x73/0x82 [nft_hash] Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org> Acked-by: NThomas Graf <tgraf@suug.ch>
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由 David Howells 提交于
An edit script should be considered inaccessible by a function once it has called assoc_array_apply_edit() or assoc_array_cancel_edit(). However, assoc_array_gc() is accessing the edit script just after the gc_complete: label. Reported-by: NAndreea-Cristina Bernat <bernat.ada@gmail.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Reviewed-by: NAndreea-Cristina Bernat <bernat.ada@gmail.com> cc: shemming@brocade.com cc: paulmck@linux.vnet.ibm.com Cc: stable@vger.kernel.org Signed-off-by: NJames Morris <james.l.morris@oracle.com>
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- 30 8月, 2014 1 次提交
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由 Dave Jones 提交于
I was puzzled why /proc/$$/stack had disappeared, until I figured out I had disabled the last debug option that did a 'select STACKTRACE'. This patch makes the option show up at config time, so it can be enabled without enabling any of the more heavyweight debug options. Signed-off-by: NDave Jones <davej@redhat.com> Acked-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 28 8月, 2014 1 次提交
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由 Rob Clark 提交于
We really don't want distro's enabling this in their kernels. Try and make that more clear. Signed-off-by: NRob Clark <robdclark@gmail.com> Acked-by: NMaarten Lankhorst <maarten.lankhorst@canonical.com> Signed-off-by: NDave Airlie <airlied@redhat.com>
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- 15 8月, 2014 2 次提交
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由 Thomas Graf 提交于
No need to export rht_obj(), all inner to outer object translations occur internally. It was intended to be used with rht_for_each() which now primarily serves as the iterator for rhashtable_remove_pprev() to effectively flush and free the full table. Signed-off-by: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
Properly annotate next pointers as access is RCU protected in the lookup path. Signed-off-by: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 09 8月, 2014 6 次提交
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由 Laura Abbott 提交于
Rather than have architectures #define ARCH_HAS_SG_CHAIN in an architecture specific scatterlist.h, make it a proper Kconfig option and use that instead. At same time, remove the header files are are now mostly useless and just include asm-generic/scatterlist.h. [sfr@canb.auug.org.au: powerpc files now need asm/dma.h] Signed-off-by: NLaura Abbott <lauraa@codeaurora.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc] Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Yinghai Lu 提交于
Now with 64bit bzImage and kexec tools, we support ramdisk that size is bigger than 2g, as we could put it above 4G. Found compressed initramfs image could not be decompressed properly. It turns out that image length is int during decompress detection, and it will become < 0 when length is more than 2G. Furthermore, during decompressing len as int is used for inbuf count, that has problem too. Change len to long, that should be ok as on 32 bit platform long is 32bits. Tested with following compressed initramfs image as root with kexec. gzip, bzip2, xz, lzma, lzop, lz4. run time for populate_rootfs(): size name Nehalem-EX Westmere-EX Ivybridge-EX 9034400256 root_img : 26s 24s 30s 3561095057 root_img.lz4 : 28s 27s 27s 3459554629 root_img.lzo : 29s 29s 28s 3219399480 root_img.gz : 64s 62s 49s 2251594592 root_img.xz : 262s 260s 183s 2226366598 root_img.lzma: 386s 376s 277s 2901482513 root_img.bz2 : 635s 599s Signed-off-by: NYinghai Lu <yinghai@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Rashika Kheria <rashika.kheria@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Cc: P J P <ppandit@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: "Daniel M. Weeks" <dan@danweeks.net> Cc: Alexandre Courbot <acourbot@nvidia.com> Cc: Jan Beulich <JBeulich@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Yinghai Lu 提交于
During testing initrd (>2G) support, find decompress/lz4 does not work with initrd at all. decompress_* should support: 1. inbuf[]/outbuf[] for kernel preboot. 2. inbuf[]/flush() for initramfs 3. fill()/flush() for initrd. in the unlz4 does not handle case 3, as input len is passed as 0, and it failed in first try. Fix that add one extra if (fill) checking, and get out if EOF from the fill(). Signed-off-by: NYinghai Lu <yinghai@kernel.org> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Himangi Saraogi 提交于
Use BUG_ON(x) rather than if(x) BUG(); The semantic patch that fixes this problem is as follows: // <smpl> @@ identifier x; @@ -if (!x) BUG(); +BUG_ON(!x); // </smpl> Signed-off-by: NHimangi Saraogi <himangi774@gmail.com> Acked-by: NJulia Lawall <julia.lawall@lip6.fr> Cc: Stefani Seibold <stefani@seibold.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Wei Yang 提交于
In case 1, it passes down the BLACK color from G to p and u, and maintains the color of n. By doing so, it maintains the black height of the sub-tree. While in the comment, it marks the color of n to BLACK. This is a typo and not consistents with the code. This patch fixs this typo in comment. Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com> Acked-by: NMichel Lespinasse <walken@google.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrey Ryabinin 提交于
I'm working on address sanitizer project for kernel. Recently we started experiments with stack instrumentation, to detect out-of-bounds read/write bugs on stack. Just after booting I've hit out-of-bounds read on stack in idr_for_each (and in __idr_remove_all as well): struct idr_layer **paa = &pa[0]; while (id >= 0 && id <= max) { ... while (n < fls(id)) { n += IDR_BITS; p = *--paa; <--- here we are reading pa[-1] value. } } Despite the fact that after this dereference we are exiting out of loop and never use p, such behaviour is undefined and should be avoided. Fix this by moving pointer derference to the beggining of the loop, right before we will use it. Signed-off-by: NAndrey Ryabinin <a.ryabinin@samsung.com> Reviewed-by: NLai Jiangshan <laijs@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Alexey Preobrazhensky <preobr@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 8月, 2014 23 次提交
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由 Rasmus Villemoes 提交于
Apparently, bitmap_andnot is supposed to return whether the new bitmap is empty. But it didn't take potential garbage bits in the last word into account. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Apparently, bitmap_and is supposed to return whether the new bitmap is empty. But it didn't take potential garbage bits in the last word into account. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
__reg_op(..., REG_OP_ALLOC) always returns 0, so we might as well use that and save an instruction. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Changing the pos parameter of __reg_op to unsigned allows the compiler to generate slightly smaller and simpler code. Also update its callers bitmap_*_region to receive and pass unsigned int. The return types of bitmap_find_free_region and bitmap_allocate_region are still int to allow a negative error code to be returned. An int is certainly capable of representing any realistic return value. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
A few lines above, it was stated that positions for non-set bits are mapped to -1, which is obviously also what the code does. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
We want len to be the index of the first '\n', or the length of the string if there is no newline. This is a good example of the usefulness of strchrnul(). Use that instead, thus eliminating a branch and a call to strlen(). Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "start" is non-negative. Also, use the names "start" and "len" for the two parameters for consistency with bitmap_set. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "start" is non-negative. Also, use the names "start" and "len" for the two parameters in both header file and implementation, instead of the previous mix. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. I didn't change the return type, since that might change the semantics of some expression containing a call to bitmap_weight(). Certainly an int is capable of holding the result. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
This change is only for consistency with the changes to the other bitmap_* functions; it doesn't change the size of the generated code: inside BITS_TO_LONGS there is a sizeof(long), which causes bits to be interpreted as unsigned anyway. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Since the extra bits are "don't care", there is no reason to mask the last word to the used bits when complementing. This shaves off yet a few bytes. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Many functions in lib/bitmap.c start with an expression such as lim = bits/BITS_PER_LONG. Since bits has type (signed) int, and since gcc cannot know that it is in fact non-negative, it generates worse code than it could. These patches, mostly consisting of changing various parameters to unsigned, gives a slight overall code reduction: add/remove: 1/1 grow/shrink: 8/16 up/down: 251/-414 (-163) function old new delta tick_device_uses_broadcast 335 425 +90 __irq_alloc_descs 498 554 +56 __bitmap_andnot 73 115 +42 __bitmap_and 70 101 +31 bitmap_weight - 11 +11 copy_hugetlb_page_range 752 762 +10 follow_hugetlb_page 846 854 +8 hugetlb_init 1415 1417 +2 hugetlb_nrpages_setup 130 131 +1 hugetlb_add_hstate 377 376 -1 bitmap_allocate_region 82 80 -2 select_task_rq_fair 2202 2191 -11 hweight_long 66 55 -11 __reg_op 230 219 -11 dm_stats_message 2849 2833 -16 bitmap_parselist 92 74 -18 __bitmap_weight 115 97 -18 __bitmap_subset 153 129 -24 __bitmap_full 128 104 -24 __bitmap_empty 120 96 -24 bitmap_set 179 149 -30 bitmap_clear 185 155 -30 __bitmap_equal 136 105 -31 __bitmap_intersects 148 108 -40 __bitmap_complement 109 67 -42 tick_device_setup_broadcast_func.isra 81 - -81 [The increases in __bitmap_and{,not} are due to bug fixes 17/18,18/18. No idea why bitmap_weight suddenly appears.] While 163 bytes treewide is insignificant, I believe the bitmap functions are often called with locks held, so saving even a few cycles might be worth it. While making these changes, I found a few other things that might be worth including. 16,17,18 are actual bug fixes. The rest shouldn't change the behaviour of any of the functions, provided no-one passed negative nbits values. If something should come up, it should be fairly bisectable. A few issues I thought about, but didn't know what to do with: * Many of the functions misbehave if nbits is compile-time 0; the out-of-line functions generally handle 0 correctly. bitmap_fill() is particularly bad, whether the 0 is known at compile time or not. It would probably be nice to add detection of at least compile-time 0 and handle that appropriately. * I didn't change __bitmap_shift_{left,right} to use unsigned because I want to fully understand why the algorithm works before making that change. However, AFAICT, they behave correctly for all (positive) shift amounts. This is not the case for the small_const_nbits versions. If for example nbits = n = BITS_PER_LONG, the shift operators turn into no-ops (at least on x86), so one get *dst = *src, whereas one would expect to get *dst=0. That difference in behaviour is somewhat annoying. This patch (of 18): The compiler can generate slightly smaller and simpler code when it knows that "nbits" is non-negative. Since no-one passes a negative bit-count, this shouldn't affect the semantics. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrew Morton 提交于
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Don Mullis <don.mullis@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The helper merge_and_restore_back_links() makes sure to call the caller's cmp function during the final ->prev pointer fixup, so that the cmp function may call cond_resched(). However, if the cmp function does not call cond_resched() at all, this is entirely redundant. If it does, doing at least two function calls for every two pointer assignments is a bit excessive. This patch limits the calls to once for every 256 iterations. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Don Mullis <don.mullis@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
There is no reason to maintain the list structure while freeing the debug elements. Aside from the redundant pointer manipulations, it is also inefficient from a locality-of-reference viewpoint, since they are visited in a random order (wrt. the order they were allocated). Furthermore, if we jumped to exit: after detecting list corruption, it is actually dangerous. So just free the elements in the order they were allocated, using the backing array elts. Allocate that using kcalloc(), so that if allocation of one of the debug element fails, we just end up calling kfree(NULL) for the trailing elements. Minor details: Use sizeof(*elts) instead of sizeof(void *), and return err immediately when allocation of elts fails, to avoid introducing another label just before the final return statement. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Don Mullis <don.mullis@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Add a check to make sure that the prev pointer of the list head points to the last element on the list. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Don Mullis <don.mullis@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Don Mullis <don.mullis@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
Use kernel.h definition. Signed-off-by: NFabian Frederick <fabf@skynet.be> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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