From c96fc2d85f4a827e3bb2abe7de2394a1fb8a0fe7 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 23 May 2016 16:23:57 -0700 Subject: [PATCH] signal: make oom_flags a bool Currently the size of "struct signal_struct"->oom_flags member is sizeof(unsigned) bytes, but only one flag OOM_FLAG_ORIGIN which is updated by current thread is defined. We can convert OOM_FLAG_ORIGIN into a bool, and reuse the saved bytes for updating from the OOM killer and/or the OOM reaper thread. By the way, do we care about a race window between run_store() and swapoff() because it would be theoretically possible that two threads sharing the "struct signal_struct" concurrently call respective functions? If we care, we can make oom_flags an atomic_t. Signed-off-by: Tetsuo Handa Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/oom.h | 9 +++------ include/linux/sched.h | 6 +++++- include/linux/types.h | 1 - 3 files changed, 8 insertions(+), 8 deletions(-) diff --git a/include/linux/oom.h b/include/linux/oom.h index d3f533f2f481..83469522690a 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -50,24 +50,21 @@ enum oom_scan_t { OOM_SCAN_SELECT, /* always select this thread first */ }; -/* Thread is the potential origin of an oom condition; kill first on oom */ -#define OOM_FLAG_ORIGIN ((__force oom_flags_t)0x1) - extern struct mutex oom_lock; static inline void set_current_oom_origin(void) { - current->signal->oom_flags |= OOM_FLAG_ORIGIN; + current->signal->oom_flag_origin = true; } static inline void clear_current_oom_origin(void) { - current->signal->oom_flags &= ~OOM_FLAG_ORIGIN; + current->signal->oom_flag_origin = false; } static inline bool oom_task_origin(const struct task_struct *p) { - return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN); + return p->signal->oom_flag_origin; } extern void mark_oom_victim(struct task_struct *tsk); diff --git a/include/linux/sched.h b/include/linux/sched.h index 2c036de6c1ee..21c26e78aec5 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -794,7 +794,11 @@ struct signal_struct { struct tty_audit_buf *tty_audit_buf; #endif - oom_flags_t oom_flags; + /* + * Thread is the potential origin of an oom condition; kill first on + * oom + */ + bool oom_flag_origin; short oom_score_adj; /* OOM kill score adjustment */ short oom_score_adj_min; /* OOM kill score adjustment min value. * Only settable by CAP_SYS_RESOURCE. */ diff --git a/include/linux/types.h b/include/linux/types.h index 70dd3dfde631..baf718324f4a 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -156,7 +156,6 @@ typedef u32 dma_addr_t; typedef unsigned __bitwise__ gfp_t; typedef unsigned __bitwise__ fmode_t; -typedef unsigned __bitwise__ oom_flags_t; #ifdef CONFIG_PHYS_ADDR_T_64BIT typedef u64 phys_addr_t;