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2024-08-04profiling: remove profile=sleep supportTetsuo Handa1-10/+1
The kernel sleep profile is no longer working due to a recursive locking bug introduced by commit 42a20f86dc19 ("sched: Add wrapper for get_wchan() to keep task blocked") Booting with the 'profile=sleep' kernel command line option added or executing # echo -n sleep > /sys/kernel/profiling after boot causes the system to lock up. Lockdep reports kthreadd/3 is trying to acquire lock: ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70 but task is already holding lock: ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370 with the call trace being lock_acquire+0xc8/0x2f0 get_wchan+0x32/0x70 __update_stats_enqueue_sleeper+0x151/0x430 enqueue_entity+0x4b0/0x520 enqueue_task_fair+0x92/0x6b0 ttwu_do_activate+0x73/0x140 try_to_wake_up+0x213/0x370 swake_up_locked+0x20/0x50 complete+0x2f/0x40 kthread+0xfb/0x180 However, since nobody noticed this regression for more than two years, let's remove 'profile=sleep' support based on the assumption that nobody needs this functionality. Fixes: 42a20f86dc19 ("sched: Add wrapper for get_wchan() to keep task blocked") Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-29profiling: remove stale percpu flip buffer variablesLinus Torvalds1-6/+0
For some reason I didn't see this issue on my arm64 or x86-64 builds, but Stephen Rothwell reports that commit 2accfdb7eff6 ("profiling: attempt to remove per-cpu profile flip buffer") left these static variables around, and the powerpc build is unhappy about them: kernel/profile.c:52:28: warning: 'cpu_profile_flip' defined but not used [-Wunused-variable] 52 | static DEFINE_PER_CPU(int, cpu_profile_flip); | ^~~~~~~~~~~~~~~~ .. So remove these stale left-over remnants too. Fixes: 2accfdb7eff6 ("profiling: attempt to remove per-cpu profile flip buffer") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-29profiling: attempt to remove per-cpu profile flip bufferLinus Torvalds1-181/+2
This is the really old legacy kernel profiling code, which has long since been obviated by "real profiling" (ie 'prof' and company), and mainly remains as a source of syzbot reports. There are anecdotal reports that people still use it for boot-time profiling, but it's unlikely that such use would care about the old NUMA optimizations in this code from 2004 (commit ad02973d42: "profile: 512x Altix timer interrupt livelock fix" in the BK import archive at [1]) So in order to head off future syzbot reports, let's try to simplify this code and get rid of the per-cpu profile buffers that are quite a large portion of the complexity footprint of this thing (including CPU hotplug callbacks etc). It's unlikely anybody will actually notice, or possibly, as Thomas put it: "Only people who indulge in nostalgia will notice :)". That said, if it turns out that this code is actually actively used by somebody, we can always revert this removal. Thus the "attempt" in the summary line. [ Note: in a small nod to "the profiling code can cause NUMA problems", this also removes the "increment the last entry in the profiling array on any unknown hits" logic. That would account any program counter in a module to that single counter location, and might exacerbate any NUMA cacheline bouncing issues ] Link: https://lore.kernel.org/all/CAHk-=wgs52BxT4Zjmjz8aNvHWKxf5_ThBY4bYL1Y6CTaNL2dTw@mail.gmail.com/ Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git [1] Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-29profiling: remove prof_cpu_maskTetsuo Handa1-40/+6
syzbot is reporting uninit-value at profile_hits(), for there is a race window between if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL)) return -ENOMEM; cpumask_copy(prof_cpu_mask, cpu_possible_mask); in profile_init() and cpumask_available(prof_cpu_mask) && cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) in profile_tick(); prof_cpu_mask remains uninitialzed until cpumask_copy() completes while cpumask_available(prof_cpu_mask) returns true as soon as alloc_cpumask_var(&prof_cpu_mask) completes. We could replace alloc_cpumask_var() with zalloc_cpumask_var() and call cpumask_copy() from create_proc_profile() on only UP kernels, for profile_online_cpu() calls cpumask_set_cpu() as needed via cpuhp_setup_state(CPUHP_AP_ONLINE_DYN) on SMP kernels. But this patch removes prof_cpu_mask because it seems unnecessary. The cpumask_test_cpu(smp_processor_id(), prof_cpu_mask) test in profile_tick() is likely always true due to a CPU cannot call profile_tick() if that CPU is offline and cpumask_set_cpu(cpu, prof_cpu_mask) is called when that CPU becomes online and cpumask_clear_cpu(cpu, prof_cpu_mask) is called when that CPU becomes offline . This test could be false during transition between online and offline. But according to include/linux/cpuhotplug.h , CPUHP_PROFILE_PREPARE belongs to PREPARE section, which means that the CPU subjected to profile_dead_cpu() cannot be inside profile_tick() (i.e. no risk of use-after-free bug) because interrupt for that CPU is disabled during PREPARE section. Therefore, this test is guaranteed to be true, and can be removed. (Since profile_hits() checks prof_buffer != NULL, we don't need to check prof_buffer != NULL here unless get_irq_regs() or user_mode() is such slow that we want to avoid when prof_buffer == NULL). do_profile_hits() is called from profile_tick() from timer interrupt only if cpumask_test_cpu(smp_processor_id(), prof_cpu_mask) is true and prof_buffer is not NULL. But syzbot is also reporting that sometimes do_profile_hits() is called while current thread is still doing vzalloc(), where prof_buffer must be NULL at this moment. This indicates that multiple threads concurrently tried to write to /sys/kernel/profiling interface, which caused that somebody else try to re-allocate prof_buffer despite somebody has already allocated prof_buffer. Fix this by using serialization. Reported-by: syzbot <syzbot+b1a83ab2a9eb9321fbdd@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=b1a83ab2a9eb9321fbdd Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: syzbot <syzbot+b1a83ab2a9eb9321fbdd@syzkaller.appspotmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-04-27profiling: Remove create_prof_cpu_mask().Tetsuo Handa1-43/+0
create_prof_cpu_mask() is no longer used after commit 1f44a225777e ("s390: convert interrupt handling to use generic hardirq"). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-09-11kernel/profile.c: simplify duplicated code in profile_setup()wuchi1-18/+14
The code to parse option string "schedule/sleep/kvm" of cmdline in function profile_setup is redundant, so simplify that. Link: https://lkml.kernel.org/r/20220901003121.53597-1-wuchi.zero@gmail.com Signed-off-by: wuchi <wuchi.zero@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foudation.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29profile: setup_profiling_timer() is moslty not implementedBen Dooks1-2/+6
The setup_profiling_timer() is mostly un-implemented by many architectures. In many places it isn't guarded by CONFIG_PROFILE which is needed for it to be used. Make it a weak symbol in kernel/profile.c and remove the 'return -EINVAL' implementations from the kenrel. There are a couple of architectures which do return 0 from the setup_profiling_timer() function but they don't seem to do anything else with it. To keep the /proc compatibility for now, leave these for a future update or removal. On ARM, this fixes the following sparse warning: arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static? Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16profiling: fix shift too large makes kernel panicChen Zhongjin1-0/+7
2d186afd04d6 ("profiling: fix shift-out-of-bounds bugs") limits shift value by [0, BITS_PER_LONG -1], which means [0, 63]. However, syzbot found that the max shift value should be the bit number of (_etext - _stext). If shift is outside of this, the "buffer_bytes" will be zero and will cause kzalloc(0). Then the kernel panics due to dereferencing the returned pointer 16. This can be easily reproduced by passing a large number like 60 to enable profiling and then run readprofile. LOGS: BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 6148067 P4D 6148067 PUD 6142067 PMD 0 PREEMPT SMP CPU: 4 PID: 184 Comm: readprofile Not tainted 5.18.0+ #162 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_profile+0x104/0x220 RSP: 0018:ffffc900006fbe80 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888006150000 RSI: 0000000000000001 RDI: ffffffff82aba4a0 RBP: 000000000188bb60 R08: 0000000000000010 R09: ffff888006151000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82aba4a0 R13: 0000000000000000 R14: ffffc900006fbf08 R15: 0000000000020c30 FS: 000000000188a8c0(0000) GS:ffff88803ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000006144000 CR4: 00000000000006e0 Call Trace: <TASK> proc_reg_read+0x56/0x70 vfs_read+0x9a/0x1b0 ksys_read+0xa1/0xe0 ? fpregs_assert_state_consistent+0x1e/0x40 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x4d4b4e RSP: 002b:00007ffebb668d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000188a8a0 RCX: 00000000004d4b4e RDX: 0000000000000400 RSI: 000000000188bb60 RDI: 0000000000000003 RBP: 0000000000000003 R08: 000000000000006e R09: 0000000000000000 R10: 0000000000000041 R11: 0000000000000246 R12: 000000000188bb60 R13: 0000000000000400 R14: 0000000000000000 R15: 000000000188bb60 </TASK> Modules linked in: CR2: 0000000000000010 Killed ---[ end trace 0000000000000000 ]--- Check prof_len in profile_init() to prevent it be zero. Link: https://lkml.kernel.org/r/20220531012854.229439-1-chenzhongjin@huawei.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-01-08exit: Remove profile_handoff_taskEric W. Biederman1-23/+0
All profile_handoff_task does is notify the task_free_notifier chain. The helpers task_handoff_register and task_handoff_unregister are used to add and delete entries from that chain and are never called. So remove the dead code and make it much easier to read and reason about __put_task_struct. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lkml.kernel.org/r/87fspyw6m0.fsf@email.froward.int.ebiederm.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-01-08exit: Remove profile_task_exit & profile_munmapEric W. Biederman1-50/+0
When I say remove I mean remove. All profile_task_exit and profile_munmap do is call a blocking notifier chain. The helpers profile_task_register and profile_task_unregister are not called anywhere in the tree. Which means this is all dead code. So remove the dead code and make it easier to read do_exit. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lkml.kernel.org/r/20220103213312.9144-1-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-09-08profiling: fix shift-out-of-bounds bugsPavel Skripkin1-10/+11
Syzbot reported shift-out-of-bounds bug in profile_init(). The problem was in incorrect prof_shift. Since prof_shift value comes from userspace we need to clamp this value into [0, BITS_PER_LONG -1] boundaries. Second possible shiht-out-of-bounds was found by Tetsuo: sample_step local variable in read_profile() had "unsigned int" type, but prof_shift allows to make a BITS_PER_LONG shift. So, to prevent possible shiht-out-of-bounds sample_step type was changed to "unsigned long". Also, "unsigned short int" will be sufficient for storing [0, BITS_PER_LONG] value, that's why there is no need for "unsigned long" prof_shift. Link: https://lkml.kernel.org/r/20210813140022.5011-1-paskripkin@gmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-10kernel: Initialize cpumask before parsingTetsuo Handa1-1/+1
KMSAN complains that new_value at cpumask_parse_user() from write_irq_affinity() from irq_affinity_proc_write() is uninitialized. [ 148.133411][ T5509] ===================================================== [ 148.135383][ T5509] BUG: KMSAN: uninit-value in find_next_bit+0x325/0x340 [ 148.137819][ T5509] [ 148.138448][ T5509] Local variable ----new_value.i@irq_affinity_proc_write created at: [ 148.140768][ T5509] irq_affinity_proc_write+0xc3/0x3d0 [ 148.142298][ T5509] irq_affinity_proc_write+0xc3/0x3d0 [ 148.143823][ T5509] ===================================================== Since bitmap_parse() from cpumask_parse_user() calls find_next_bit(), any alloc_cpumask_var() + cpumask_parse_user() sequence has possibility that find_next_bit() accesses uninitialized cpu mask variable. Fix this problem by replacing alloc_cpumask_var() with zalloc_cpumask_var(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp
2020-02-04proc: convert everything to "struct proc_ops"Alexey Dobriyan1-12/+12
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04kernel/profile.c: use cpumask_available to check for NULL cpumaskNathan Chancellor1-3/+3
When building with clang + -Wtautological-pointer-compare, these instances pop up: kernel/profile.c:339:6: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare] if (prof_cpu_mask != NULL) ^~~~~~~~~~~~~ ~~~~ kernel/profile.c:376:6: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare] if (prof_cpu_mask != NULL) ^~~~~~~~~~~~~ ~~~~ kernel/profile.c:406:26: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare] if (!user_mode(regs) && prof_cpu_mask != NULL && ^~~~~~~~~~~~~ ~~~~ 3 warnings generated. This can be addressed with the cpumask_available helper, introduced in commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") to fix warnings like this while keeping the code the same. Link: https://github.com/ClangBuiltLinux/linux/issues/747 Link: http://lkml.kernel.org/r/20191022191957.9554-1-natechancellor@gmail.com Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-31mm: remove include/linux/bootmem.hMike Rapoport1-1/+1
Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-02sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() ↵Ingo Molnar1-0/+2
from <linux/sched.h> to <linux/sched/stat.h> But first update usage sites with the new header dependency. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-15profile: Convert to hotplug state machineSebastian Andrzej Siewior1-116/+65
Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. A lot of code is removed because the for-loop is used and create_hash_tables() is removed since its purpose is covered by the startup / teardown hooks. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.649867675@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-22profile: hide unused functions when !CONFIG_PROC_FSArnd Bergmann1-2/+2
A couple of functions and variables in the profile implementation are used only on SMP systems by the procfs code, but are unused if either procfs is disabled or in uniprocessor kernels. gcc prints a harmless warning about the unused symbols: kernel/profile.c:243:13: error: 'profile_flip_buffers' defined but not used [-Werror=unused-function] static void profile_flip_buffers(void) ^ kernel/profile.c:266:13: error: 'profile_discard_flip_buffers' defined but not used [-Werror=unused-function] static void profile_discard_flip_buffers(void) ^ kernel/profile.c:330:12: error: 'profile_cpu_callback' defined but not used [-Werror=unused-function] static int profile_cpu_callback(struct notifier_block *info, ^ This adds further #ifdef to the file, to annotate exactly in which cases they are used. I have done several thousand ARM randconfig kernels with this patch applied and no longer get any warnings in this file. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Robin Holt <robinmholt@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-09sched/debug: Make schedstats a runtime tunable that is disabled by defaultMel Gorman1-0/+1
schedstats is very useful during debugging and performance tuning but it incurs overhead to calculate the stats. As such, even though it can be disabled at build time, it is often enabled as the information is useful. This patch adds a kernel command-line and sysctl tunable to enable or disable schedstats on demand (when it's built in). It is disabled by default as someone who knows they need it can also learn to enable it when necessary. The benefits are dependent on how scheduler-intensive the workload is. If it is then the patch reduces the number of cycles spent calculating the stats with a small benefit from reducing the cache footprint of the scheduler. These measurements were taken from a 48-core 2-socket machine with Xeon(R) E5-2670 v3 cpus although they were also tested on a single socket machine 8-core machine with Intel i7-3770 processors. netperf-tcp 4.5.0-rc1 4.5.0-rc1 vanilla nostats-v3r1 Hmean 64 560.45 ( 0.00%) 575.98 ( 2.77%) Hmean 128 766.66 ( 0.00%) 795.79 ( 3.80%) Hmean 256 950.51 ( 0.00%) 981.50 ( 3.26%) Hmean 1024 1433.25 ( 0.00%) 1466.51 ( 2.32%) Hmean 2048 2810.54 ( 0.00%) 2879.75 ( 2.46%) Hmean 3312 4618.18 ( 0.00%) 4682.09 ( 1.38%) Hmean 4096 5306.42 ( 0.00%) 5346.39 ( 0.75%) Hmean 8192 10581.44 ( 0.00%) 10698.15 ( 1.10%) Hmean 16384 18857.70 ( 0.00%) 18937.61 ( 0.42%) Small gains here, UDP_STREAM showed nothing intresting and neither did the TCP_RR tests. The gains on the 8-core machine were very similar. tbench4 4.5.0-rc1 4.5.0-rc1 vanilla nostats-v3r1 Hmean mb/sec-1 500.85 ( 0.00%) 522.43 ( 4.31%) Hmean mb/sec-2 984.66 ( 0.00%) 1018.19 ( 3.41%) Hmean mb/sec-4 1827.91 ( 0.00%) 1847.78 ( 1.09%) Hmean mb/sec-8 3561.36 ( 0.00%) 3611.28 ( 1.40%) Hmean mb/sec-16 5824.52 ( 0.00%) 5929.03 ( 1.79%) Hmean mb/sec-32 10943.10 ( 0.00%) 10802.83 ( -1.28%) Hmean mb/sec-64 15950.81 ( 0.00%) 16211.31 ( 1.63%) Hmean mb/sec-128 15302.17 ( 0.00%) 15445.11 ( 0.93%) Hmean mb/sec-256 14866.18 ( 0.00%) 15088.73 ( 1.50%) Hmean mb/sec-512 15223.31 ( 0.00%) 15373.69 ( 0.99%) Hmean mb/sec-1024 14574.25 ( 0.00%) 14598.02 ( 0.16%) Hmean mb/sec-2048 13569.02 ( 0.00%) 13733.86 ( 1.21%) Hmean mb/sec-3072 12865.98 ( 0.00%) 13209.23 ( 2.67%) Small gains of 2-4% at low thread counts and otherwise flat. The gains on the 8-core machine were slightly different tbench4 on 8-core i7-3770 single socket machine Hmean mb/sec-1 442.59 ( 0.00%) 448.73 ( 1.39%) Hmean mb/sec-2 796.68 ( 0.00%) 794.39 ( -0.29%) Hmean mb/sec-4 1322.52 ( 0.00%) 1343.66 ( 1.60%) Hmean mb/sec-8 2611.65 ( 0.00%) 2694.86 ( 3.19%) Hmean mb/sec-16 2537.07 ( 0.00%) 2609.34 ( 2.85%) Hmean mb/sec-32 2506.02 ( 0.00%) 2578.18 ( 2.88%) Hmean mb/sec-64 2511.06 ( 0.00%) 2569.16 ( 2.31%) Hmean mb/sec-128 2313.38 ( 0.00%) 2395.50 ( 3.55%) Hmean mb/sec-256 2110.04 ( 0.00%) 2177.45 ( 3.19%) Hmean mb/sec-512 2072.51 ( 0.00%) 2053.97 ( -0.89%) In constract, this shows a relatively steady 2-3% gain at higher thread counts. Due to the nature of the patch and the type of workload, it's not a surprise that the result will depend on the CPU used. hackbench-pipes 4.5.0-rc1 4.5.0-rc1 vanilla nostats-v3r1 Amean 1 0.0637 ( 0.00%) 0.0660 ( -3.59%) Amean 4 0.1229 ( 0.00%) 0.1181 ( 3.84%) Amean 7 0.1921 ( 0.00%) 0.1911 ( 0.52%) Amean 12 0.3117 ( 0.00%) 0.2923 ( 6.23%) Amean 21 0.4050 ( 0.00%) 0.3899 ( 3.74%) Amean 30 0.4586 ( 0.00%) 0.4433 ( 3.33%) Amean 48 0.5910 ( 0.00%) 0.5694 ( 3.65%) Amean 79 0.8663 ( 0.00%) 0.8626 ( 0.43%) Amean 110 1.1543 ( 0.00%) 1.1517 ( 0.22%) Amean 141 1.4457 ( 0.00%) 1.4290 ( 1.16%) Amean 172 1.7090 ( 0.00%) 1.6924 ( 0.97%) Amean 192 1.9126 ( 0.00%) 1.9089 ( 0.19%) Some small gains and losses and while the variance data is not included, it's close to the noise. The UMA machine did not show anything particularly different pipetest 4.5.0-rc1 4.5.0-rc1 vanilla nostats-v2r2 Min Time 4.13 ( 0.00%) 3.99 ( 3.39%) 1st-qrtle Time 4.38 ( 0.00%) 4.27 ( 2.51%) 2nd-qrtle Time 4.46 ( 0.00%) 4.39 ( 1.57%) 3rd-qrtle Time 4.56 ( 0.00%) 4.51 ( 1.10%) Max-90% Time 4.67 ( 0.00%) 4.60 ( 1.50%) Max-93% Time 4.71 ( 0.00%) 4.65 ( 1.27%) Max-95% Time 4.74 ( 0.00%) 4.71 ( 0.63%) Max-99% Time 4.88 ( 0.00%) 4.79 ( 1.84%) Max Time 4.93 ( 0.00%) 4.83 ( 2.03%) Mean Time 4.48 ( 0.00%) 4.39 ( 1.91%) Best99%Mean Time 4.47 ( 0.00%) 4.39 ( 1.91%) Best95%Mean Time 4.46 ( 0.00%) 4.38 ( 1.93%) Best90%Mean Time 4.45 ( 0.00%) 4.36 ( 1.98%) Best50%Mean Time 4.36 ( 0.00%) 4.25 ( 2.49%) Best10%Mean Time 4.23 ( 0.00%) 4.10 ( 3.13%) Best5%Mean Time 4.19 ( 0.00%) 4.06 ( 3.20%) Best1%Mean Time 4.13 ( 0.00%) 4.00 ( 3.39%) Small improvement and similar gains were seen on the UMA machine. The gain is small but it stands to reason that doing less work in the scheduler is a good thing. The downside is that the lack of schedstats and tracepoints may be surprising to experts doing performance analysis until they find the existence of the schedstats= parameter or schedstats sysctl. It will be automatically activated for latencytop and sleep profiling to alleviate the problem. For tracepoints, there is a simple warning as it's not safe to activate schedstats in the context when it's known the tracepoint may be wanted but is unavailable. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <mgalbraith@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1454663316-22048-1-git-send-email-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-08mm: rename alloc_pages_exact_node() to __alloc_pages_node()Vlastimil Babka1-4/+4
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>
2015-02-13profile: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-2/+1
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06kernel/profile.c: use static const char instead of static charFabian Frederick1-3/+3
schedstr, sleepstr and kvmstr are only used in strcmp & strlen Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06kernel/profile.c: convert printk to pr_foo()Fabian Frederick1-9/+5
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07Merge tag 'cpu-hotplug-3.15-rc1' of ↵Linus Torvalds1-5/+15
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull CPU hotplug notifiers registration fixes from Rafael Wysocki: "The purpose of this single series of commits from Srivatsa S Bhat (with a small piece from Gautham R Shenoy) touching multiple subsystems that use CPU hotplug notifiers is to provide a way to register them that will not lead to deadlocks with CPU online/offline operations as described in the changelog of commit 93ae4f978ca7f ("CPU hotplug: Provide lockless versions of callback registration functions"). The first three commits in the series introduce the API and document it and the rest simply goes through the users of CPU hotplug notifiers and converts them to using the new method" * tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) net/iucv/iucv.c: Fix CPU hotplug callback registration net/core/flow.c: Fix CPU hotplug callback registration mm, zswap: Fix CPU hotplug callback registration mm, vmstat: Fix CPU hotplug callback registration profile: Fix CPU hotplug callback registration trace, ring-buffer: Fix CPU hotplug callback registration xen, balloon: Fix CPU hotplug callback registration hwmon, via-cputemp: Fix CPU hotplug callback registration hwmon, coretemp: Fix CPU hotplug callback registration thermal, x86-pkg-temp: Fix CPU hotplug callback registration octeon, watchdog: Fix CPU hotplug callback registration oprofile, nmi-timer: Fix CPU hotplug callback registration intel-idle: Fix CPU hotplug callback registration clocksource, dummy-timer: Fix CPU hotplug callback registration drivers/base/topology.c: Fix CPU hotplug callback registration acpi-cpufreq: Fix CPU hotplug callback registration zsmalloc: Fix CPU hotplug callback registration scsi, fcoe: Fix CPU hotplug callback registration scsi, bnx2fc: Fix CPU hotplug callback registration scsi, bnx2i: Fix CPU hotplug callback registration ...
2014-04-03kernel: audit/fix non-modular users of module_init in core codePaul Gortmaker1-1/+1
Code that is obj-y (always built-in) or dependent on a bool Kconfig (built-in or absent) can never be modular. So using module_init as an alias for __initcall can be somewhat misleading. Fix these up now, so that we can relocate module_init from init.h into module.h in the future. If we don't do this, we'd have to add module.h to obviously non-modular code, and that would be a worse thing. The audit targets the following module_init users for change: kernel/user.c obj-y kernel/kexec.c bool KEXEC (one instance per arch) kernel/profile.c bool PROFILING kernel/hung_task.c bool DETECT_HUNG_TASK kernel/sched/stats.c bool SCHEDSTATS kernel/user_namespace.c bool USER_NS Note that direct use of __initcall is discouraged, vs. one of the priority categorized subgroups. As __initcall gets mapped onto device_initcall, our use of subsys_initcall (which makes sense for these files) will thus change this registration from level 6-device to level 4-subsys (i.e. slightly earlier). However no observable impact of that difference has been observed during testing. Also, two instances of missing ";" at EOL are fixed in kexec. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-20profile: Fix CPU hotplug callback registrationSrivatsa S. Bhat1-5/+15
Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the profile code by using this latter form of callback registration. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-10mm: fix GFP_THISNODE callers and clarifyJohannes Weiner1-2/+2
GFP_THISNODE is for callers that implement their own clever fallback to remote nodes. It restricts the allocation to the specified node and does not invoke reclaim, assuming that the caller will take care of it when the fallback fails, e.g. through a subsequent allocation request without GFP_THISNODE set. However, many current GFP_THISNODE users only want the node exclusive aspect of the flag, without actually implementing their own fallback or triggering reclaim if necessary. This results in things like page migration failing prematurely even when there is easily reclaimable memory available, unless kswapd happens to be running already or a concurrent allocation attempt triggers the necessary reclaim. Convert all callsites that don't implement their own fallback strategy to __GFP_THISNODE. This restricts the allocation a single node too, but at the same time allows the allocator to enter the slowpath, wake kswapd, and invoke direct reclaim if necessary, to make the allocation happen when memory is full. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-14kernel: delete __cpuinit usage from all core kernel filesPaul Gortmaker1-1/+1
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the uses of the __cpuinit macros from C files in the core kernel directories (kernel, init, lib, mm, and include) that don't really have a specific maintainer. [1] https://lkml.org/lkml/2013/5/20/589 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-05-01proc: Supply PDE attribute setting accessor functionsDavid Howells1-1/+1
Supply accessor functions to set attributes in proc_dir_entry structs. The following are supplied: proc_set_size() and proc_set_user(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> cc: linuxppc-dev@lists.ozlabs.org cc: linux-media@vger.kernel.org cc: netdev@vger.kernel.org cc: linux-wireless@vger.kernel.org cc: linux-pci@vger.kernel.org cc: netfilter-devel@vger.kernel.org cc: alsa-devel@alsa-project.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09create_proc_cpu_mask() doesn't need an argument...Al Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-24profiling: Remove unused timer hookFrederic Weisbecker1-24/+0
The last remaining user was oprofile and its use has been removed a while ago in commit bc078e4eab65f11bba ("oprofile: convert oprofile from timer_hook to hrtimer"). There doesn't seem to be any upstream user of this hook for about two years now. And I'm not even aware of any out of tree user. Let's remove it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1356191991-2251-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-06propagate name change to comments in kernel sourceNadia Yvette Chambers1-3/+4
I've legally changed my name with New York State, the US Social Security Administration, et al. This patch propagates the name change and change in initials and login to comments in the kernel source as well. Signed-off-by: Nadia Yvette Chambers <nyc@holomorphy.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-10-31kernel: Map most files to use export.h instead of module.hPaul Gortmaker1-1/+1
The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include <linux/module.h> +#include <linux/export.h> This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-05-26kernel/profile.c: remove some duplicate code from profile_hits()Rakib Mullick1-7/+9
profile_hits() has a common check for prof_on and prof_buffer regardless of SMP or !SMP. So, remove some duplicate code by splitting profile_hits into two. [akpm@linux-foundation.org: make do_profile_hits static] Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-31profile: Use vzalloc() rather than vmalloc() & memset()Jesper Juhl1-4/+2
There's no reason to memset() manually when we have vzalloc(). Signed-off-by: Jesper Juhl <jj@chaosbits.net> Cc: Arjan van de Ven <arjan@infradead.org> Cc: William Irwin <wli@holomorphy.com> LKML-Reference: <alpine.LNX.2.00.1010302150310.1572@swampdragon.chaosbits.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann1-0/+1
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-05-27numa: in-kernel profiling: use cpu_to_mem() for per cpu allocationsLee Schermerhorn1-2/+2
In kernel profiling requires that we be able to allocate "local" memory for each cpu. Use "cpu_to_mem()" instead of "cpu_to_node()" to support memoryless nodes. Depends on the "numa_mem_id()" patch. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27kernel/: convert cpu notifier to return encapsulate errno valueAkinobu Mita1-2/+2
By the previous modification, the cpu notifier can return encapsulate errno value. This converts the cpu notifiers for kernel/*.c Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-14profile: fix stats and data leakageHugh Dickins1-1/+3
If the kernel is large or the profiling step small, /proc/profile leaks data and readprofile shows silly stats, until readprofile -r has reset the buffer: clear the prof_buffer when it is vmalloc()ed. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-20kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_fileAlexey Dobriyan1-21/+24
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29profile: suppress warning about large allocations when profile=1 is specifiedMel Gorman1-2/+3
When profile= is used, a large buffer is allocated early at boot. This can be larger than what the page allocator can provide so it prints a warning. However, the caller is able to handle the situation so this patch suppresses the warning. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16page allocator: do not check NUMA node ID when the caller knows the node is ↵Mel Gorman1-4/+4
valid Callers of alloc_pages_node() can optionally specify -1 as a node to mean "allocate from the current node". However, a number of the callers in fast paths know for a fact their node is valid. To avoid a comparison and branch, this patch adds alloc_pages_exact_node() that only checks the nid with VM_BUG_ON(). Callers that know their node is valid are then converted. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Paul Mundt <lethal@linux-sh.org> [for the SLOB NUMA bits] Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11x86: remove some alloc_bootmem_cpumask_var callingYinghai Lu1-6/+0
Now that we set up the slab allocator earlier, we can get rid of some alloc_bootmem_cpumask_var() calls in boot code. Cc: Ingo Molnar <mingo@elte.hu> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-02-10profiling: fix broken profiling regressionHugh Dickins1-0/+3
Impact: fix broken /proc/profile on UP machines Commit c309b917cab55799ea489d7b5f1b77025d9f8462 "cpumask: convert kernel/profile.c" broke profiling. prof_cpu_mask was previously initialized to CPU_MASK_ALL, but left uninitialized in that commit. We need to copy cpu_possible_mask (cpu_online_mask is not enough). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06profile: don't include <asm/ptrace.h> twice.KOSAKI Motohiro1-1/+0
Currently, kernel/profile.c include <asm/ptrace.h> twice. It can be removed. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-01cpumask: convert kernel/profile.cRusty Russell1-13/+25
Impact: Reduce kernel memory usage, use new cpumask API. Avoid a static cpumask_t for prof_cpu_mask, and an on-stack cpumask_t in prof_cpu_mask_write_proc. Both become cpumask_var_t. prof_cpu_mask is only allocated when profiling is on, but the NULL checks are optimized out by gcc for the !CPUMASK_OFFSTACK case. Also removed some strange and unnecessary casts. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30Merge branch 'master' of ↵Rusty Russell1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
2008-12-13cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and ↵Rusty Russell1-2/+2
cpulist_scnprintf to take pointers. Impact: change calling convention of existing cpumask APIs Most cpumask functions started with cpus_: these have been replaced by cpumask_ ones which take struct cpumask pointers as expected. These four functions don't have good replacement names; fortunately they're rarely used, so we just change them over. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: paulus@samba.org Cc: mingo@redhat.com Cc: tony.luck@intel.com Cc: ralf@linux-mips.org Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: cl@linux-foundation.org Cc: srostedt@redhat.com
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