The patch titled
Subject: mm/madvise: check fatal signal pending of target process
has been added to the -mm tree. Its filename is
mm-check-fatal-signal-pending-of-target-process.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-check-fatal-signal-pending-of-target-process.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-check-fatal-signal-pending-of-target-process.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
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>
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: <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
@@ -36,6 +36,7 @@
struct madvise_walk_private {
struct mmu_gather *tlb;
bool pageout;
+ struct task_struct *target_task;
};
/*
@@ -316,6 +317,10 @@ 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;
@@ -471,12 +476,14 @@ 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);
@@ -484,7 +491,8 @@ 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)
{
@@ -497,19 +505,21 @@ 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);
@@ -533,7 +543,8 @@ 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)
{
@@ -549,7 +560,7 @@ 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;
@@ -929,7 +940,8 @@ 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) {
@@ -938,9 +950,9 @@ 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);
@@ -1140,7 +1152,8 @@ 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;
_
Patches currently in -mm which might be from minchan@xxxxxxxxxx are
mm-pass-task-and-mm-to-do_madvise.patch
mm-introduce-external-memory-hinting-api.patch
mm-check-fatal-signal-pending-of-target-process.patch
pid-move-pidfd_get_pid-function-to-pidc.patch
mm-support-both-pid-and-pidfd-for-process_madvise.patch
