From: Minchan Kim <minchan@xxxxxxxxxx> Subject: mm/madvise: check fatal signal pending of target process Bail out to prevent unnecessary CPU overhead if target process has pending fatal signal during (MADV_COLD|MADV_PAGEOUT) operation. Link: http://lkml.kernel.org/r/20200302193630.68771-4-minchan@xxxxxxxxxx Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: Christian Brauner <christian@xxxxxxxxxx> Cc: Daniel Colascione <dancol@xxxxxxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: John Dias <joaodias@xxxxxxxxxx> Cc: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Oleksandr Natalenko <oleksandr@xxxxxxxxxx> Cc: Sandeep Patil <sspatil@xxxxxxxxxx> Cc: SeongJae Park <sj38.park@xxxxxxxxx> Cc: SeongJae Park <sjpark@xxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Sonny Rao <sonnyrao@xxxxxxxxxx> Cc: Tim Murray <timmurray@xxxxxxxxxx> Cc: Christian Brauner <christian.brauner@xxxxxxxxxx> Cc: <linux-man@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/madvise.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) --- a/mm/madvise.c~mm-check-fatal-signal-pending-of-target-process +++ a/mm/madvise.c @@ -39,6 +39,7 @@ struct madvise_walk_private { struct mmu_gather *tlb; bool pageout; + struct task_struct *target_task; }; /* @@ -319,6 +320,10 @@ static int madvise_cold_or_pageout_pte_r if (fatal_signal_pending(current)) return -EINTR; + if (private->target_task && + fatal_signal_pending(private->target_task)) + return -EINTR; + #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (pmd_trans_huge(*pmd)) { pmd_t orig_pmd; @@ -480,12 +485,14 @@ static const struct mm_walk_ops cold_wal }; static void madvise_cold_page_range(struct mmu_gather *tlb, + struct task_struct *task, struct vm_area_struct *vma, unsigned long addr, unsigned long end) { struct madvise_walk_private walk_private = { .pageout = false, .tlb = tlb, + .target_task = task, }; tlb_start_vma(tlb, vma); @@ -493,7 +500,8 @@ static void madvise_cold_page_range(stru tlb_end_vma(tlb, vma); } -static long madvise_cold(struct vm_area_struct *vma, +static long madvise_cold(struct task_struct *task, + struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start_addr, unsigned long end_addr) { @@ -506,19 +514,21 @@ static long madvise_cold(struct vm_area_ lru_add_drain(); tlb_gather_mmu(&tlb, mm, start_addr, end_addr); - madvise_cold_page_range(&tlb, vma, start_addr, end_addr); + madvise_cold_page_range(&tlb, task, vma, start_addr, end_addr); tlb_finish_mmu(&tlb, start_addr, end_addr); return 0; } static void madvise_pageout_page_range(struct mmu_gather *tlb, + struct task_struct *task, struct vm_area_struct *vma, unsigned long addr, unsigned long end) { struct madvise_walk_private walk_private = { .pageout = true, .tlb = tlb, + .target_task = task, }; tlb_start_vma(tlb, vma); @@ -542,7 +552,8 @@ static inline bool can_do_pageout(struct inode_permission(file_inode(vma->vm_file), MAY_WRITE) == 0; } -static long madvise_pageout(struct vm_area_struct *vma, +static long madvise_pageout(struct task_struct *task, + struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start_addr, unsigned long end_addr) { @@ -558,7 +569,7 @@ static long madvise_pageout(struct vm_ar lru_add_drain(); tlb_gather_mmu(&tlb, mm, start_addr, end_addr); - madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); + madvise_pageout_page_range(&tlb, task, vma, start_addr, end_addr); tlb_finish_mmu(&tlb, start_addr, end_addr); return 0; @@ -938,7 +949,8 @@ static int madvise_inject_error(int beha #endif static long -madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, +madvise_vma(struct task_struct *task, struct vm_area_struct *vma, + struct vm_area_struct **prev, unsigned long start, unsigned long end, int behavior) { switch (behavior) { @@ -947,9 +959,9 @@ madvise_vma(struct vm_area_struct *vma, case MADV_WILLNEED: return madvise_willneed(vma, prev, start, end); case MADV_COLD: - return madvise_cold(vma, prev, start, end); + return madvise_cold(task, vma, prev, start, end); case MADV_PAGEOUT: - return madvise_pageout(vma, prev, start, end); + return madvise_pageout(task, vma, prev, start, end); case MADV_FREE: case MADV_DONTNEED: return madvise_dontneed_free(vma, prev, start, end, behavior); @@ -1166,7 +1178,8 @@ int do_madvise(struct task_struct *targe tmp = end; /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ - error = madvise_vma(vma, &prev, start, tmp, behavior); + error = madvise_vma(target_task, vma, &prev, + start, tmp, behavior); if (error) goto out; start = tmp; _
