hulk inclusion category: bugfix bugzilla: NA CVE: NA

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When files cgroup is enabled, it's will leads syscall performance regression in UnixBench. Add a helper files_cgroup_enabled() and use it to control if use files cgroup, wen can use cgroup_disable=files in cmdline to disable files cgroup.

syscall of UnixBench (large is better) enable files cgroup: 2868.5 disable files cgroup: 3177.0 disable config of files cgroup: 3186.5

Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-by: Tao Hou houtao1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- .../admin-guide/kernel-parameters.txt | 7 ++++--- fs/file.c | 21 ++++++++++++------- include/linux/filescontrol.h | 6 ++++++ 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 564b14b0b9b84..05b9b8c6034cd 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -492,9 +492,10 @@ a single hierarchy - foo isn't visible as an individually mountable subsystem - {Currently only "memory" controller deal with this and - cut the overhead, others just disable the usage. So - only cgroup_disable=memory is actually worthy} + {Currently "memory" and "files" controller deal with + this and cut the overhead, others just disable the usage. + So cgroup_disable=memory and cgroup_disable=files are + actually worthy}

cgroup_no_v1= [KNL] Disable one, multiple, all cgroup controllers in v1 Format: { controller[,controller...] | "all" } diff --git a/fs/file.c b/fs/file.c index 6dd55640e91fc..570b757fc469f 100644 --- a/fs/file.c +++ b/fs/file.c @@ -295,7 +295,8 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp) new_fdt->full_fds_bits = newf->full_fds_bits_init; new_fdt->fd = &newf->fd_array[0]; #ifdef CONFIG_CGROUP_FILES - files_cgroup_assign(newf); + if (files_cgroup_enabled()) + files_cgroup_assign(newf); #endif

spin_lock(&oldf->file_lock); @@ -361,6 +362,8 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)

rcu_assign_pointer(newf->fdt, new_fdt); #ifdef CONFIG_CGROUP_FILES + if (!files_cgroup_enabled()) + return newf; spin_lock(&newf->file_lock); if (!files_cgroup_alloc_fd(newf, files_cgroup_count_fds(newf))) { spin_unlock(&newf->file_lock); @@ -385,7 +388,8 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)

out_release: #ifdef CONFIG_CGROUP_FILES - files_cgroup_remove(newf); + if (files_cgroup_enabled()) + files_cgroup_remove(newf); #endif kmem_cache_free(files_cachep, newf); out: @@ -413,7 +417,8 @@ static struct fdtable *close_files(struct files_struct * files) struct file * file = xchg(&fdt->fd[i], NULL); if (file) { #ifdef CONFIG_CGROUP_FILES - files_cgroup_unalloc_fd(files, 1); + if (files_cgroup_enabled()) + files_cgroup_unalloc_fd(files, 1); #endif filp_close(file, files); cond_resched(); @@ -424,7 +429,8 @@ static struct fdtable *close_files(struct files_struct * files) } } #ifdef CONFIG_CGROUP_FILES - files_cgroup_remove(files); + if (files_cgroup_enabled()) + files_cgroup_remove(files); #endif

return fdt; @@ -546,7 +552,7 @@ int __alloc_fd(struct files_struct *files, if (error) goto repeat; #ifdef CONFIG_CGROUP_FILES - if (files_cgroup_alloc_fd(files, 1)) { + if (files_cgroup_enabled() && files_cgroup_alloc_fd(files, 1)) { error = -EMFILE; goto out; } @@ -589,7 +595,7 @@ static void __put_unused_fd(struct files_struct *files, unsigned int fd) { struct fdtable *fdt = files_fdtable(files); #ifdef CONFIG_CGROUP_FILES - if (test_bit(fd, fdt->open_fds)) + if (files_cgroup_enabled() && test_bit(fd, fdt->open_fds)) files_cgroup_unalloc_fd(files, 1); #endif __clear_open_fd(fd, fdt); @@ -878,7 +884,8 @@ __releases(&files->file_lock) goto out; } #ifdef CONFIG_CGROUP_FILES - if (!tofree && files_cgroup_alloc_fd(files, 1)) { + if (files_cgroup_enabled() && + !tofree && files_cgroup_alloc_fd(files, 1)) { err = -EMFILE; goto out; } diff --git a/include/linux/filescontrol.h b/include/linux/filescontrol.h index 49dc620cf64ec..0182f145a3392 100644 --- a/include/linux/filescontrol.h +++ b/include/linux/filescontrol.h @@ -19,6 +19,7 @@ #define _LINUX_FILESCONTROL_H

#include <linux/fdtable.h> +#include <linux/cgroup.h>

#ifdef CONFIG_CGROUP_FILES

@@ -30,5 +31,10 @@ extern struct files_struct init_files; void files_cgroup_assign(struct files_struct *files); void files_cgroup_remove(struct files_struct *files);

+static inline bool files_cgroup_enabled(void) +{ + return cgroup_subsys_enabled(files_cgrp_subsys); +} + #endif /* CONFIG_CGROUP_FILES */ #endif /* _LINUX_FILESCONTROL_H */