[CRIU] [PATCH] rst-malloc: introduce rst_mem_align
Andrew Vagin
avagin at virtuozzo.com
Wed Feb 10 13:45:56 PST 2016
On Wed, Feb 10, 2016 at 11:49:10AM -0700, Tycho Andersen wrote:
> Since we need to align some allocations (but not most of them), let's
> switch to a helper called rst_mem_align, which aligns the free list pointer
> for the next allocation.
>
> v2: always rst_mem_align() before the beginning of each "set" of
> allocations; add a note about recommended usage of rst_mem_align().
>
Acked-by: Andrew Vagin <avagin at virtuozzo.com>
I think we need to merge rst_mem_align and rst_mem_cpos. We can rename
rst_mem_cpos to rst_mem_align_cpos() and do everything in this function.
Thanks,
Andrew
> Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
> CC: Cyrill Gorcunov <gorcunov at gmail.com>
> CC: Andrey Vagin <avagin at openvz.org>
> ---
> cr-restore.c | 31 +++++++++++++++++++++----------
> include/rst-malloc.h | 13 ++++++++++---
> rst-malloc.c | 28 ++++++++--------------------
> sk-tcp.c | 3 ++-
> timerfd.c | 3 ++-
> 5 files changed, 43 insertions(+), 35 deletions(-)
>
> diff --git a/cr-restore.c b/cr-restore.c
> index 2155dbc..ec16626 100644
> --- a/cr-restore.c
> +++ b/cr-restore.c
> @@ -775,7 +775,7 @@ static int collect_child_pids(int state, int *n)
> if (pi->state != state)
> continue;
>
> - child = rst_mem_alloc_cont(sizeof(*child), RM_PRIVATE);
> + child = rst_mem_alloc(sizeof(*child), RM_PRIVATE);
> if (!child)
> return -1;
>
> @@ -788,12 +788,14 @@ static int collect_child_pids(int state, int *n)
>
> static int collect_helper_pids()
> {
> + rst_mem_align(RM_PRIVATE);
> helpers_pos = rst_mem_cpos(RM_PRIVATE);
> return collect_child_pids(TASK_HELPER, &n_helpers);
> }
>
> static int collect_zombie_pids()
> {
> + rst_mem_align(RM_PRIVATE);
> zombies_pos = rst_mem_cpos(RM_PRIVATE);
> return collect_child_pids(TASK_DEAD, &n_zombies);
> }
> @@ -2133,6 +2135,7 @@ out:
>
> static int prepare_task_entries(void)
> {
> + rst_mem_align(RM_SHREMAP);
> task_entries_pos = rst_mem_cpos(RM_SHREMAP);
> task_entries = rst_mem_alloc(sizeof(*task_entries), RM_SHREMAP);
> if (!task_entries) {
> @@ -2432,7 +2435,7 @@ static int prepare_posix_timers_from_fd(int pid)
> if (ret <= 0)
> break;
>
> - t = rst_mem_alloc_cont(sizeof(struct restore_posix_timer), RM_PRIVATE);
> + t = rst_mem_alloc(sizeof(struct restore_posix_timer), RM_PRIVATE);
> if (!t)
> break;
>
> @@ -2457,6 +2460,7 @@ static int prepare_posix_timers(int pid, CoreEntry *core)
> TaskTimersEntry *tte = core->tc->timers;
> struct restore_posix_timer *t;
>
> + rst_mem_align(RM_PRIVATE);
> posix_timers_cpos = rst_mem_cpos(RM_PRIVATE);
>
> if (!tte)
> @@ -2464,7 +2468,7 @@ static int prepare_posix_timers(int pid, CoreEntry *core)
>
> posix_timers_nr = tte->n_posix;
> for (i = 0; i < posix_timers_nr; i++) {
> - t = rst_mem_alloc_cont(sizeof(struct restore_posix_timer), RM_PRIVATE);
> + t = rst_mem_alloc(sizeof(struct restore_posix_timer), RM_PRIVATE);
> if (!t)
> goto out;
>
> @@ -2623,7 +2627,7 @@ static int prepare_rlimits_from_fd(int pid)
> if (ret <= 0)
> break;
>
> - r = rst_mem_alloc_cont(sizeof(*r), RM_PRIVATE);
> + r = rst_mem_alloc(sizeof(*r), RM_PRIVATE);
> if (!r) {
> pr_err("Can't allocate memory for resource %d\n",
> rlims_nr);
> @@ -2654,13 +2658,14 @@ static int prepare_rlimits(int pid, CoreEntry *core)
> TaskRlimitsEntry *rls = core->tc->rlimits;
> struct rlimit *r;
>
> + rst_mem_align(RM_PRIVATE);
> rlims_cpos = rst_mem_cpos(RM_PRIVATE);
>
> if (!rls)
> return prepare_rlimits_from_fd(pid);
>
> for (i = 0; i < rls->n_rlimits; i++) {
> - r = rst_mem_alloc_cont(sizeof(*r), RM_PRIVATE);
> + r = rst_mem_alloc(sizeof(*r), RM_PRIVATE);
> if (!r) {
> pr_err("Can't allocate memory for resource %d\n", i);
> return -1;
> @@ -2684,7 +2689,7 @@ static int signal_to_mem(SiginfoEntry *sie)
> siginfo_t *info, *t;
>
> info = (siginfo_t *) sie->siginfo.data;
> - t = rst_mem_alloc_cont(sizeof(siginfo_t), RM_PRIVATE);
> + t = rst_mem_alloc(sizeof(siginfo_t), RM_PRIVATE);
> if (!t)
> return -1;
>
> @@ -2802,7 +2807,7 @@ static void rst_reloc_creds(struct thread_restore_args *thread_args,
> static struct thread_creds_args *
> rst_prep_creds_args(CredsEntry *ce, unsigned long *prev_pos)
> {
> - unsigned long this_pos = rst_mem_cpos(RM_PRIVATE);
> + unsigned long this_pos;
> struct thread_creds_args *args;
>
> if (!verify_cap_size(ce)) {
> @@ -2812,8 +2817,10 @@ rst_prep_creds_args(CredsEntry *ce, unsigned long *prev_pos)
> return ERR_PTR(-EINVAL);
> }
>
> + rst_mem_align(RM_PRIVATE);
> + this_pos = rst_mem_cpos(RM_PRIVATE);
>
> - args = rst_mem_alloc_cont(sizeof(*args), RM_PRIVATE);
> + args = rst_mem_alloc(sizeof(*args), RM_PRIVATE);
> if (!args)
> return ERR_PTR(-ENOMEM);
>
> @@ -2838,6 +2845,7 @@ rst_prep_creds_args(CredsEntry *ce, unsigned long *prev_pos)
> size_t lsm_profile_len;
> char *lsm_profile;
>
> + rst_mem_align(RM_PRIVATE);
> args->mem_lsm_profile_pos = rst_mem_cpos(RM_PRIVATE);
> lsm_profile_len = strlen(rendered);
> lsm_profile = rst_mem_alloc(lsm_profile_len + 1, RM_PRIVATE);
> @@ -2874,6 +2882,7 @@ rst_prep_creds_args(CredsEntry *ce, unsigned long *prev_pos)
> if (ce->n_groups) {
> unsigned int *groups;
>
> + rst_mem_align(RM_PRIVATE);
> args->mem_groups_pos = rst_mem_cpos(RM_PRIVATE);
> groups = rst_mem_alloc(ce->n_groups * sizeof(u32), RM_PRIVATE);
> if (!groups)
> @@ -3016,11 +3025,12 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
> * walk them and m(un|re)map.
> */
>
> + rst_mem_align(RM_PRIVATE);
> tgt_vmas = rst_mem_cpos(RM_PRIVATE);
> list_for_each_entry(vma, &vmas->h, list) {
> VmaEntry *vme;
>
> - vme = rst_mem_alloc_cont(sizeof(*vme), RM_PRIVATE);
> + vme = rst_mem_alloc(sizeof(*vme), RM_PRIVATE);
> if (!vme)
> goto err_nv;
>
> @@ -3034,11 +3044,12 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
> * Put info about AIO rings, they will get remapped
> */
>
> + rst_mem_align(RM_PRIVATE);
> aio_rings = rst_mem_cpos(RM_PRIVATE);
> for (i = 0; i < mm->n_aios; i++) {
> struct rst_aio_ring *raio;
>
> - raio = rst_mem_alloc_cont(sizeof(*raio), RM_PRIVATE);
> + raio = rst_mem_alloc(sizeof(*raio), RM_PRIVATE);
> if (!raio)
> goto err_nv;
>
> diff --git a/include/rst-malloc.h b/include/rst-malloc.h
> index f205622..9a47b33 100644
> --- a/include/rst-malloc.h
> +++ b/include/rst-malloc.h
> @@ -47,8 +47,8 @@ enum {
> extern void rst_mem_switch_to_private(void);
> /*
> * Reports a cookie of a current shared buffer position, that
> - * can later be used in rst_mem_cpos() to find out the object
> - * pointer.
> + * can later be used in rst_mem_remap_ptr() to find out the object
> + * pointer in the restorer blob.
> */
> extern unsigned long rst_mem_cpos(int type);
> extern void *rst_mem_remap_ptr(unsigned long pos, int type);
> @@ -58,8 +58,15 @@ extern void *rst_mem_remap_ptr(unsigned long pos, int type);
> * last object can be freed (pop-ed from buffer).
> */
> extern void *rst_mem_alloc(unsigned long size, int type);
> -extern void *rst_mem_alloc_cont(unsigned long size, int type);
> extern void rst_mem_free_last(int type);
> +
> +/* Word-align the current freelist pointer for the next allocation. If we don't
> + * align pointers, some futex and atomic operations can fail. Additionally,
> + * there are performance benefits to aligning arrays, so it is recommended to
> + * align before calling rst_mem_cpos() in most cases.
> + */
> +extern void rst_mem_align(int type);
> +
> /*
> * Routines to remap SHREMAP and PRIVATE into restorer address space
> */
> diff --git a/rst-malloc.c b/rst-malloc.c
> index 8e17255..f4afcaf 100644
> --- a/rst-malloc.c
> +++ b/rst-malloc.c
> @@ -128,7 +128,7 @@ unsigned long rst_mem_cpos(int type)
> {
> struct rst_mem_type_s *t = &rst_mems[type];
> BUG_ON(!t->remapable || !t->enabled);
> - return ((void*) round_up((unsigned long)t->free_mem, sizeof(void *))) - t->buf;
> + return t->free_mem - t->buf;
> }
>
> void *rst_mem_remap_ptr(unsigned long pos, int type)
> @@ -138,7 +138,7 @@ void *rst_mem_remap_ptr(unsigned long pos, int type)
> return t->buf + pos;
> }
>
> -static void *__rst_mem_alloc(unsigned long size, int type)
> +void *rst_mem_alloc(unsigned long size, int type)
> {
> struct rst_mem_type_s *t = &rst_mems[type];
> void *ret;
> @@ -158,24 +158,6 @@ static void *__rst_mem_alloc(unsigned long size, int type)
> return ret;
> }
>
> -void *rst_mem_alloc(unsigned long size, int type)
> -{
> - struct rst_mem_type_s *t = &rst_mems[type];
> -
> - t->free_mem = (void *) round_up((unsigned long)t->free_mem, sizeof(void *));
> -
> - return __rst_mem_alloc(size, type);
> -}
> -
> -/* Allocate memory without gaps with a previous slice */
> -void *rst_mem_alloc_cont(unsigned long size, int type)
> -{
> - struct rst_mem_type_s *t = &rst_mems[type];
> - BUG_ON(!t->remapable);
> -
> - return __rst_mem_alloc(size, type);
> -}
> -
> void rst_mem_free_last(int type)
> {
> struct rst_mem_type_s *t = &rst_mems[type];
> @@ -187,6 +169,12 @@ void rst_mem_free_last(int type)
> t->last = 0; /* next free_last would be no-op */
> }
>
> +void rst_mem_align(int type)
> +{
> + struct rst_mem_type_s *t = &rst_mems[type];
> + t->free_mem = (void *) round_up((unsigned long)t->free_mem, sizeof(void *));
> +}
> +
> unsigned long rst_mem_lock(void)
> {
> /*
> diff --git a/sk-tcp.c b/sk-tcp.c
> index 8e17024..4d4cf83 100644
> --- a/sk-tcp.c
> +++ b/sk-tcp.c
> @@ -678,6 +678,7 @@ int rst_tcp_socks_prep(void)
> {
> struct inet_sk_info *ii;
>
> + rst_mem_align(RM_PRIVATE);
> rst_tcp_socks_cpos = rst_mem_cpos(RM_PRIVATE);
> list_for_each_entry(ii, &rst_tcp_repair_sockets, rlist) {
> struct rst_tcp_sock *rs;
> @@ -689,7 +690,7 @@ int rst_tcp_socks_prep(void)
> if (ii->sk_fd == -1)
> continue;
>
> - rs = rst_mem_alloc_cont(sizeof(*rs), RM_PRIVATE);
> + rs = rst_mem_alloc(sizeof(*rs), RM_PRIVATE);
> if (!rs)
> return -1;
>
> diff --git a/timerfd.c b/timerfd.c
> index b91e047..6ca1229 100644
> --- a/timerfd.c
> +++ b/timerfd.c
> @@ -115,11 +115,12 @@ int rst_timerfd_prep(void)
> struct timerfd_info *ti;
> struct restore_timerfd *t;
>
> + rst_mem_align(RM_PRIVATE);
> rst_timerfd_cpos = rst_mem_cpos(RM_PRIVATE);
> list_for_each_entry(ti, &rst_timerfds, rlist) {
> TimerfdEntry *tfe = ti->tfe;
>
> - t = rst_mem_alloc_cont(sizeof(*t), RM_PRIVATE);
> + t = rst_mem_alloc(sizeof(*t), RM_PRIVATE);
> if (!t)
> return -1;
>
> --
> 2.5.0
>
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