- 10 Sep, 2015 40 commits
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Jan Harkes authored
Dan Carpenter discovered a buffer overflow in the Coda file system readlink code. A userspace file system daemon can return a 4096 byte result which then triggers a one byte write past the allocated readlink result buffer. This does not trigger with an unmodified Coda implementation because Coda has a 1024 byte limit for symbolic links, however other userspace file systems using the Coda kernel module could be affected. Although this is an obvious overflow, I don't think this has to be handled as too sensitive from a security perspective because the overflow is on the Coda userspace daemon side which already needs root to open Coda's kernel device and to mount the file system before we get to the point that links can be read. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Jan Harkes <jaharkes@cs.cmu.edu> Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
"CONST <comparison> variable" checks like: if (NULL != foo) and while (0 < bar(...)) where a constant (or what appears to be a constant like an upper case identifier) is on the left of a comparison are generally preferred to be written using the constant on the right side like: if (foo != NULL) and while (bar(...) > 0) Add a test for this. Add a --fix option too, but only do it when the code is immediately surrounded by parentheses to avoid misfixing things like "(0 < bar() + constant)" Signed-off-by:Joe Perches <joe@perches.com> Cc: Nicolas Morey Chaisemartin <nmorey@kalray.eu> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Joe Perches authored
commit 61031952 ("arch, x86: pmem api for ensuring durability of persistent memory updates") added a new __pmem annotation for sparse verification. Add __pmem to the $Sparse variable so checkpatch can appropriately ignore uses of this attribute too. Signed-off-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by:
Andy Whitcroft <apw@canonical.com> Signed-off-by:
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Eddie Kovsky authored
Using checkpatch.pl with Perl 5.22.0 generates the following warning: Unescaped left brace in regex is deprecated, passed through in regex; This patch fixes the warnings by escaping occurrences of the left brace inside the regular expression. Signed-off-by:Eddie Kovsky <ewk@edkovsky.org> Cc: Joe Perches <joe@perches.com> Signed-off-by:
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Joe Perches authored
Fixes: and Link: lines may exceed 75 chars in the commit log. So too can stack dump and dmesg lines and lines that seem like filenames. And Fixes: lines don't need to have a "commit" prefix before the commit id. Add exceptions for these types of lines. Signed-off-by:
Paul Bolle <pebolle@tiscali.nl> Signed-off-by:
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Joe Perches authored
Using 0x%d is wrong. Emit a message when it happens. Miscellanea: Improve the %Lu warning to match formats like %16Lu. Signed-off-by:
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Joe Perches authored
Making --strict the default for staging may help some people submit patches without obvious defects. Signed-off-by:
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Joe Perches authored
Some of the block comment tests that are used only for networking are appropriate for all patches. For example, these styles are not encouraged: /* block comment without introductory * */ and /* * block comment with line terminating */ Remove the networking specific test and add comments. There are some infrequent false positives where code is lazily commented out using /* and */ rather than using #if 0/#endif blocks like: /* case foo: case bar: */ case baz: Signed-off-by:
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Joe Perches authored
commit 34d8815f ("checkpatch: add --showfile to allow input via pipe to show filenames") broke the --emacs with --file option. Fix it. Signed-off-by:
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Joe Perches authored
Sergey Senozhatsky has modified several destroy functions that can now be called with NULL values. - kmem_cache_destroy() - mempool_destroy() - dma_pool_destroy() Update checkpatch to warn when those functions are preceded by an if. Update checkpatch to --fix all the calls too only when the code style form is using leading tabs. from: if (foo) <func>(foo); to: <func>(foo); Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by:
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Joe Perches authored
Some really long declaration macros exist. For instance; DEFINE_DMA_BUF_EXPORT_INFO(exp_info); and DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(name, description) Increase the limit from 2 words to 6 after DECLARE/DEFINE uses. Signed-off-by:
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Joe Perches authored
Many lines exist like if (foo) bar; where the tabbed indentation of the branch is not one more than the "if" line above it. checkpatch should emit a warning on those lines. Miscellenea: o Remove comments from branch blocks o Skip blank lines in block Signed-off-by:
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Joe Perches authored
Using BUG/BUG_ON crashes the kernel and is just unfriendly. Enable code that emits a warning on BUG/BUG_ON use. Make the code emit the message at WARNING level when scanning a patch and at CHECK level when scanning files so that script users don't feel an obligation to fix code that might be above their pay grade. Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Tested-by:
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Joe Perches authored
Commit IDs should have commit descriptions too. Warn when a 12 to 40 byte SHA-1 is used in commit logs. Signed-off-by:
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Wang Long authored
In kmalloc_oob_krealloc_less, I think it is better to test the size2 boundary. If we do not call krealloc, the access of position size1 will still cause out-of-bounds and access of position size2 does not. After call krealloc, the access of position size2 cause out-of-bounds. So using size2 is more correct. Signed-off-by:
Wang Long <long.wanglong@huawei.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by:
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Wang Long authored
Signed-off-by:
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Kees Cook authored
To further clarify the purpose of the "esc" argument, rename it to "only" to reflect that it is a limit, not a list of additional characters to escape. Signed-off-by:
Kees Cook <keescook@chromium.org> Suggested-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
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Kees Cook authored
The esc argument is used to reduce which characters will be escaped. For example, using " " with ESCAPE_SPACE will not produce any escaped spaces. Signed-off-by:
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Linus Walleij authored
print_hex_dump_debug() is likely supposed to be analogous to pr_debug() or dev_dbg() & friends. Currently it will adhere to dynamic debug, but will not stub out prints if CONFIG_DEBUG is not set. Let's make it do the right thing, because I am tired of having my dmesg buffer full of hex dumps on production systems. Signed-off-by:
Linus Walleij <linus.walleij@linaro.org> Signed-off-by:
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Pan Xinhui authored
In __bitmap_parselist we can accept whitespaces on head or tail during every parsing procedure. If input has valid ranges, there is no reason to reject the user. For example, bitmap_parselist(" 1-3, 5, ", &mask, nmaskbits). After separating the string, we get " 1-3", " 5", and " ". It's possible and reasonable to accept such string as long as the parsing result is correct. Signed-off-by:Pan Xinhui <xinhuix.pan@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by:
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Pan Xinhui authored
If string end with '-', for exapmle, bitmap_parselist("1,0-",&mask, nmaskbits), It is not in a valid pattern, so add a check after loop. Return -EINVAL on such condition. Signed-off-by: -
Pan Xinhui authored
We can avoid in-loop incrementation of ndigits. Save current totaldigits to ndigits before loop, and check ndigits against totaldigits after the loop. Signed-off-by:
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Alexey Dobriyan authored
Convert from manual allocation/copy_from_user/... to kstrto*() family which were designed for exactly that. One case can not be converted to kstrto*_from_user() to make code even more simpler because of whitespace stripping, oh well... Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
strtol(3) et al accept "-0", so should we. Signed-off-by:
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Joe Perches authored
Anil's email address bounces and he hasn't had a signoff in over 5 years. Signed-off-by:
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Jason A. Donenfeld authored
The other two implementations of pr_debug_ratelimited include pr_fmt, along with every other pr_* function. But pr_debug_ratelimited forgot to add it with the CONFIG_DYNAMIC_DEBUG implementation. This patch unifies the behavior. Signed-off-by:
Jason A. Donenfeld <Jason@zx2c4.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Joe Perches authored
Commit e0e81739 ("CRED: Add some configurable debugging [try #6]") added the kdebug mechanism to this file back in 2009. The kdebug macro calls no_printk which always evaluates arguments. Most of the kdebug uses have an unnecessary call of atomic_read(&cred->usage) Make the kdebug macro do nothing by defining it with do { if (0) no_printk(...); } while (0) when not enabled. $ size kernel/cred.o* (defconfig x86-64) text data bss dec hex filename 2748 336 8 3092 c14 kernel/cred.o.new 2788 336 8 3132 c3c kernel/cred.o.old Miscellanea: o Neaten the #define kdebug macros while there Signed-off-by:
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Wei Yongjun authored
Signed-off-by:
Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Vasily Kulikov authored
Signed-off-by:
Vasily Kulikov <segoon@openwall.com> Cc: Solar Designer <solar@openwall.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by:
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Vasily Kulikov authored
Poison pointer values should be small enough to find a room in non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space" is located starting from 0x0. Given unprivileged users cannot mmap anything below mmap_min_addr, it should be safe to use poison pointers lower than mmap_min_addr. The current poison pointer values of LIST_POISON{1,2} might be too big for mmap_min_addr values equal or less than 1 MB (common case, e.g. Ubuntu uses only 0x10000). There is little point to use such a big value given the "poison pointer space" below 1 MB is not yet exhausted. Changing it to a smaller value solves the problem for small mmap_min_addr setups. The values are suggested by Solar Designer: http://www.openwall.com/lists/oss-security/2015/05/02/6Signed-off-by: -
Waiman Long authored
The proc_subdir_lock spinlock is used to allow only one task to make change to the proc directory structure as well as looking up information in it. However, the information lookup part can actually be entered by more than one task as the pde_get() and pde_put() reference count update calls in the critical sections are atomic increment and decrement respectively and so are safe with concurrent updates. The x86 architecture has already used qrwlock which is fair and other architectures like ARM are in the process of switching to qrwlock. So unfairness shouldn't be a concern in that conversion. This patch changed the proc_subdir_lock to a rwlock in order to enable concurrent lookup. The following functions were modified to take a write lock: - proc_register() - remove_proc_entry() - remove_proc_subtree() The following functions were modified to take a read lock: - xlate_proc_name() - proc_lookup_de() - proc_readdir_de() A parallel /proc filesystem search with the "find" command (1000 threads) was run on a 4-socket Haswell-EX box (144 threads). Before the patch, the parallel search took about 39s. After the patch, the parallel find took only 25s, a saving of about 14s. The micro-benchmark that I used was artificial, but it was used to reproduce an exit hanging problem that I saw in real application. In fact, only allow one task to do a lookup seems too limiting to me. Signed-off-by:
Waiman Long <Waiman.Long@hp.com> Acked-by:
"Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Scott J Norton <scott.norton@hp.com> Cc: Douglas Hatch <doug.hatch@hp.com> Signed-off-by:
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Calvin Owens authored
Currently, /proc/<pid>/map_files/ is restricted to CAP_SYS_ADMIN, and is only exposed if CONFIG_CHECKPOINT_RESTORE is set. Each mapped file region gets a symlink in /proc/<pid>/map_files/ corresponding to the virtual address range at which it is mapped. The symlinks work like the symlinks in /proc/<pid>/fd/, so you can follow them to the backing file even if that backing file has been unlinked. Currently, files which are mapped, unlinked, and closed are impossible to stat() from userspace. Exposing /proc/<pid>/map_files/ closes this functionality "hole". Not being able to stat() such files makes noticing and explicitly accounting for the space they use on the filesystem impossible. You can work around this by summing up the space used by every file in the filesystem and subtracting that total from what statfs() tells you, but that obviously isn't great, and it becomes unworkable once your filesystem becomes large enough. This patch moves map_files/ out from behind CONFIG_CHECKPOINT_RESTORE, and adjusts the permissions enforced on it as follows: * proc_map_files_lookup() * proc_map_files_readdir() * map_files_d_revalidate() Remove the CAP_SYS_ADMIN restriction, leaving only the current restriction requiring PTRACE_MODE_READ. The information made available to userspace by these three functions is already available in /proc/PID/maps with MODE_READ, so I don't see any reason to limit them any further (see below for more detail). * proc_map_files_follow_link() This stub has been added, and requires that the user have CAP_SYS_ADMIN in order to follow the links in map_files/, since there was concern on LKML both about the potential for bypassing permissions on ancestor directories in the path to files pointed to, and about what happens with more exotic memory mappings created by some drivers (ie dma-buf). In older versions of this patch, I changed every permission check in the four functions above to enforce MODE_ATTACH instead of MODE_READ. This was an oversight on my part, and after revisiting the discussion it seems that nobody was concerned about anything outside of what is made possible by ->follow_link(). So in this version, I've left the checks for PTRACE_MODE_READ as-is. [akpm@linux-foundation.org: catch up with concurrent proc_pid_follow_link() changes] Signed-off-by:
Calvin Owens <calvinowens@fb.com> Reviewed-by:
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Vladimir Davydov authored
Reading/writing a /proc/kpage* file may take long on machines with a lot of RAM installed. Signed-off-by:
Vladimir Davydov <vdavydov@parallels.com> Suggested-by:
Andres Lagar-Cavilla <andreslc@google.com> Reviewed-by:
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Vladimir Davydov authored
As noted by Minchan, a benefit of reading idle flag from /proc/kpageflags is that one can easily filter dirty and/or unevictable pages while estimating the size of unused memory. Note that idle flag read from /proc/kpageflags may be stale in case the page was accessed via a PTE, because it would be too costly to iterate over all page mappings on each /proc/kpageflags read to provide an up-to-date value. To make sure the flag is up-to-date one has to read /sys/kernel/mm/page_idle/bitmap first. Signed-off-by:
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Vladimir Davydov authored
Knowing the portion of memory that is not used by a certain application or memory cgroup (idle memory) can be useful for partitioning the system efficiently, e.g. by setting memory cgroup limits appropriately. Currently, the only means to estimate the amount of idle memory provided by the kernel is /proc/PID/{clear_refs,smaps}: the user can clear the access bit for all pages mapped to a particular process by writing 1 to clear_refs, wait for some time, and then count smaps:Referenced. However, this method has two serious shortcomings: - it does not count unmapped file pages - it affects the reclaimer logic To overcome these drawbacks, this patch introduces two new page flags, Idle and Young, and a new sysfs file, /sys/kernel/mm/page_idle/bitmap. A page's Idle flag can only be set from userspace by setting bit in /sys/kernel/mm/page_idle/bitmap at the offset corresponding to the page, and it is cleared whenever the page is accessed either through page tables (it is cleared in page_referenced() in this case) or using the read(2) system call (mark_page_accessed()). Thus by setting the Idle flag for pages of a particular workload, which can be found e.g. by reading /proc/PID/pagemap, waiting for some time to let the workload access its working set, and then reading the bitmap file, one can estimate the amount of pages that are not used by the workload. The Young page flag is used to avoid interference with the memory reclaimer. A page's Young flag is set whenever the Access bit of a page table entry pointing to the page is cleared by writing to the bitmap file. If page_referenced() is called on a Young page, it will add 1 to its return value, therefore concealing the fact that the Access bit was cleared. Note, since there is no room for extra page flags on 32 bit, this feature uses extended page flags when compiled on 32 bit. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: kpageidle requires an MMU] [akpm@linux-foundation.org: decouple from page-flags rework] Signed-off-by: -
Vladimir Davydov authored
In the scope of the idle memory tracking feature, which is introduced by the following patch, we need to clear the referenced/accessed bit not only in primary, but also in secondary ptes. The latter is required in order to estimate wss of KVM VMs. At the same time we want to avoid flushing tlb, because it is quite expensive and it won't really affect the final result. Currently, there is no function for clearing pte young bit that would meet our requirements, so this patch introduces one. To achieve that we have to add a new mmu-notifier callback, clear_young, since there is no method for testing-and-clearing a secondary pte w/o flushing tlb. The new method is not mandatory and currently only implemented by KVM. Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by:
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Vladimir Davydov authored
/proc/kpagecgroup contains a 64-bit inode number of the memory cgroup each page is charged to, indexed by PFN. Having this information is useful for estimating a cgroup working set size. The file is present if CONFIG_PROC_PAGE_MONITOR && CONFIG_MEMCG. Signed-off-by:
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Vladimir Davydov authored
It is only used in mem_cgroup_try_charge, so fold it in and zap it. Signed-off-by:
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Vladimir Davydov authored
Hwpoison allows to filter pages by memory cgroup ino. Currently, it calls try_get_mem_cgroup_from_page to obtain the cgroup from a page and then its ino using cgroup_ino, but now we have a helper method for that, page_cgroup_ino, so use it instead. This patch also loosens the hwpoison memcg filter dependency rules - it makes it depend on CONFIG_MEMCG instead of CONFIG_MEMCG_SWAP, because hwpoison memcg filter does not require anything (nor it used to) from CONFIG_MEMCG_SWAP side. Signed-off-by:
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Vladimir Davydov authored
This patchset introduces a new user API for tracking user memory pages that have not been used for a given period of time. The purpose of this is to provide the userspace with the means of tracking a workload's working set, i.e. the set of pages that are actively used by the workload. Knowing the working set size can be useful for partitioning the system more efficiently, e.g. by tuning memory cgroup limits appropriately, or for job placement within a compute cluster. ==== USE CASES ==== The unified cgroup hierarchy has memory.low and memory.high knobs, which are defined as the low and high boundaries for the workload working set size. However, the working set size of a workload may be unknown or change in time. With this patch set, one can periodically estimate the amount of memory unused by each cgroup and tune their memory.low and memory.high parameters accordingly, therefore optimizing the overall memory utilization. Another use case is balancing workloads within a compute cluster. Knowing how much memory is not really used by a workload unit may help take a more optimal decision when considering migrating the unit to another node within the cluster. Also, as noted by Minchan, this would be useful for per-process reclaim (https://lwn.net/Articles/545668/). With idle tracking, we could reclaim idle pages only by smart user memory manager. ==== USER API ==== The user API consists of two new files: * /sys/kernel/mm/page_idle/bitmap. This file implements a bitmap where each bit corresponds to a page, indexed by PFN. When the bit is set, the corresponding page is idle. A page is considered idle if it has not been accessed since it was marked idle. To mark a page idle one should set the bit corresponding to the page by writing to the file. A value written to the file is OR-ed with the current bitmap value. Only user memory pages can be marked idle, for other page types input is silently ignored. Writing to this file beyond max PFN results in the ENXIO error. Only available when CONFIG_IDLE_PAGE_TRACKING is set. This file can be used to estimate the amount of pages that are not used by a particular workload as follows: 1. mark all pages of interest idle by setting corresponding bits in the /sys/kernel/mm/page_idle/bitmap 2. wait until the workload accesses its working set 3. read /sys/kernel/mm/page_idle/bitmap and count the number of bits set * /proc/kpagecgroup. This file contains a 64-bit inode number of the memory cgroup each page is charged to, indexed by PFN. Only available when CONFIG_MEMCG is set. This file can be used to find all pages (including unmapped file pages) accounted to a particular cgroup. Using /sys/kernel/mm/page_idle/bitmap, one can then estimate the cgroup working set size. For an example of using these files for estimating the amount of unused memory pages per each memory cgroup, please see the script attached below. ==== REASONING ==== The reason to introduce the new user API instead of using /proc/PID/{clear_refs,smaps} is that the latter has two serious drawbacks: - it does not count unmapped file pages - it affects the reclaimer logic The new API attempts to overcome them both. For more details on how it is achieved, please see the comment to patch 6. ==== PATCHSET STRUCTURE ==== The patch set is organized as follows: - patch 1 adds page_cgroup_ino() helper for the sake of /proc/kpagecgroup and patches 2-3 do related cleanup - patch 4 adds /proc/kpagecgroup, which reports cgroup ino each page is charged to - patch 5 introduces a new mmu notifier callback, clear_young, which is a lightweight version of clear_flush_young; it is used in patch 6 - patch 6 implements the idle page tracking feature, including the userspace API, /sys/kernel/mm/page_idle/bitmap - patch 7 exports idle flag via /proc/kpageflags ==== SIMILAR WORKS ==== Originally, the patch for tracking idle memory was proposed back in 2011 by Michel Lespinasse (see http://lwn.net/Articles/459269/). The main difference between Michel's patch and this one is that Michel implemented a kernel space daemon for estimating idle memory size per cgroup while this patch only provides the userspace with the minimal API for doing the job, leaving the rest up to the userspace. However, they both share the same idea of Idle/Young page flags to avoid affecting the reclaimer logic. ==== PERFORMANCE EVALUATION ==== SPECjvm2008 (https://www.spec.org/jvm2008/) was used to evaluate the performance impact introduced by this patch set. Three runs were carried out: - base: kernel without the patch - patched: patched kernel, the feature is not used - patched-active: patched kernel, 1 minute-period daemon is used for tracking idle memory For tracking idle memory, idlememstat utility was used: https://github.com/locker/idlememstat testcase base patched patched-active compiler 537.40 ( 0.00)% 532.26 (-0.96)% 538.31 ( 0.17)% compress 305.47 ( 0.00)% 301.08 (-1.44)% 300.71 (-1.56)% crypto 284.32 ( 0.00)% 282.21 (-0.74)% 284.87 ( 0.19)% derby 411.05 ( 0.00)% 413.44 ( 0.58)% 412.07 ( 0.25)% mpegaudio 189.96 ( 0.00)% 190.87 ( 0.48)% 189.42 (-0.28)% scimark.large 46.85 ( 0.00)% 46.41 (-0.94)% 47.83 ( 2.09)% scimark.small 412.91 ( 0.00)% 415.41 ( 0.61)% 421.17 ( 2.00)% serial 204.23 ( 0.00)% 213.46 ( 4.52)% 203.17 (-0.52)% startup 36.76 ( 0.00)% 35.49 (-3.45)% 35.64 (-3.05)% sunflow 115.34 ( 0.00)% 115.08 (-0.23)% 117.37 ( 1.76)% xml 620.55 ( 0.00)% 619.95 (-0.10)% 620.39 (-0.03)% composite 211.50 ( 0.00)% 211.15 (-0.17)% 211.67 ( 0.08)% time idlememstat: 17.20user 65.16system 2:15:23elapsed 1%CPU (0avgtext+0avgdata 8476maxresident)k 448inputs+40outputs (1major+36052minor)pagefaults 0swaps ==== SCRIPT FOR COUNTING IDLE PAGES PER CGROUP ==== #! /usr/bin/python # import os import stat import errno import struct CGROUP_MOUNT = "/sys/fs/cgroup/memory" BUFSIZE = 8 * 1024 # must be multiple of 8 def get_hugepage_size(): with open("/proc/meminfo", "r") as f: for s in f: k, v = s.split(":") if k == "Hugepagesize": return int(v.split()[0]) * 1024 PAGE_SIZE = os.sysconf("SC_PAGE_SIZE") HUGEPAGE_SIZE = get_hugepage_size() def set_idle(): f = open("/sys/kernel/mm/page_idle/bitmap", "wb", BUFSIZE) while True: try: f.write(struct.pack("Q", pow(2, 64) - 1)) except IOError as err: if err.errno == errno.ENXIO: break raise f.close() def count_idle(): f_flags = open("/proc/kpageflags", "rb", BUFSIZE) f_cgroup = open("/proc/kpagecgroup", "rb", BUFSIZE) with open("/sys/kernel/mm/page_idle/bitmap", "rb", BUFSIZE) as f: while f.read(BUFSIZE): pass # update idle flag idlememsz = {} while True: s1, s2 = f_flags.read(8), f_cgroup.read(8) if not s1 or not s2: break flags, = struct.unpack('Q', s1) cgino, = struct.unpack('Q', s2) unevictable = (flags >> 18) & 1 huge = (flags >> 22) & 1 idle = (flags >> 25) & 1 if idle and not unevictable: idlememsz[cgino] = idlememsz.get(cgino, 0) + \ (HUGEPAGE_SIZE if huge else PAGE_SIZE) f_flags.close() f_cgroup.close() return idlememsz if __name__ == "__main__": print "Setting the idle flag for each page..." set_idle() raw_input("Wait until the workload accesses its working set, " "then press Enter") print "Counting idle pages..." idlememsz = count_idle() for dir, subdirs, files in os.walk(CGROUP_MOUNT): ino = os.stat(dir)[stat.ST_INO] print dir + ": " + str(idlememsz.get(ino, 0) / 1024) + " kB" ==== END SCRIPT ==== This patch (of 8): Add page_cgroup_ino() helper to memcg. This function returns the inode number of the closest online ancestor of the memory cgroup a page is charged to. It is required for exporting information about which page is charged to which cgroup to userspace, which will be introduced by a following patch. Signed-off-by:
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