[RFC][PATCH 4/5] mm,ib,ipath: Use VM_PINNED

From: Peter Zijlstra
Date: Mon May 26 2014 - 11:31:09 EST


XXX: got lost, need the start vaddr in the release paths, help?

Use the mm_mpin() call to prepare the vm for a 'persistent'
get_user_pages() call.

Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Mike Marciniszyn <infinipath@xxxxxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxx>
Cc: Sean Hefty <sean.hefty@xxxxxxxxx>
Cc: Hal Rosenstock <hal.rosenstock@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
drivers/infiniband/hw/ipath/ipath_file_ops.c | 6 ++---
drivers/infiniband/hw/ipath/ipath_kernel.h | 4 +--
drivers/infiniband/hw/ipath/ipath_user_pages.c | 28 +++++++++++--------------
3 files changed, 18 insertions(+), 20 deletions(-)

--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -456,7 +456,7 @@ static int ipath_tid_update(struct ipath
ipath_stats.sps_pageunlocks++;
}
}
- ipath_release_user_pages(pagep, cnt);
+ ipath_release_user_pages(pagep, /* vaddr */, cnt);
} else {
/*
* Copy the updated array, with ipath_tid's filled in, back
@@ -572,7 +572,7 @@ static int ipath_tid_free(struct ipath_p
pci_unmap_page(dd->pcidev,
dd->ipath_physshadow[porttid + tid],
PAGE_SIZE, PCI_DMA_FROMDEVICE);
- ipath_release_user_pages(&p, 1);
+ ipath_release_user_pages(&p, /* vaddr */, 1);
ipath_stats.sps_pageunlocks++;
} else
ipath_dbg("Unused tid %u, ignoring\n", tid);
@@ -2025,7 +2025,7 @@ static void unlock_expected_tids(struct
dd->ipath_pageshadow[i] = NULL;
pci_unmap_page(dd->pcidev, dd->ipath_physshadow[i],
PAGE_SIZE, PCI_DMA_FROMDEVICE);
- ipath_release_user_pages_on_close(&ps, 1);
+ ipath_release_user_pages_on_close(&ps, /* vaddr */, 1);
cnt++;
ipath_stats.sps_pageunlocks++;
}
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -1082,8 +1082,8 @@ static inline void ipath_sdma_desc_unres
#define IPATH_DFLT_RCVHDRSIZE 9

int ipath_get_user_pages(unsigned long, size_t, struct page **);
-void ipath_release_user_pages(struct page **, size_t);
-void ipath_release_user_pages_on_close(struct page **, size_t);
+void ipath_release_user_pages(struct page **, unsigned long, size_t);
+void ipath_release_user_pages_on_close(struct page **, unsigned long, size_t);
int ipath_eeprom_read(struct ipath_devdata *, u8, void *, int);
int ipath_eeprom_write(struct ipath_devdata *, u8, const void *, int);
int ipath_tempsense_read(struct ipath_devdata *, u8 regnum);
--- a/drivers/infiniband/hw/ipath/ipath_user_pages.c
+++ b/drivers/infiniband/hw/ipath/ipath_user_pages.c
@@ -39,7 +39,7 @@
#include "ipath_kernel.h"

static void __ipath_release_user_pages(struct page **p, size_t num_pages,
- int dirty)
+ int dirty)
{
size_t i;

@@ -56,16 +56,12 @@ static void __ipath_release_user_pages(s
static int __ipath_get_user_pages(unsigned long start_page, size_t num_pages,
struct page **p, struct vm_area_struct **vma)
{
- unsigned long lock_limit;
size_t got;
int ret;

- lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
- if (num_pages > lock_limit) {
- ret = -ENOMEM;
+ ret = mm_mpin(start_page, num_pages * PAGE_SIZE);
+ if (ret)
goto bail;
- }

ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
(unsigned long) num_pages, start_page);
@@ -78,14 +74,12 @@ static int __ipath_get_user_pages(unsign
if (ret < 0)
goto bail_release;
}
-
- current->mm->pinned_vm += num_pages;
-
ret = 0;
goto bail;

bail_release:
__ipath_release_user_pages(p, got, 0);
+ mm_munpin(start_page, num_pages * PAGE_SIZE);
bail:
return ret;
}
@@ -172,13 +166,13 @@ int ipath_get_user_pages(unsigned long s
return ret;
}

-void ipath_release_user_pages(struct page **p, size_t num_pages)
+void ipath_release_user_pages(struct page **p, unsigned long start_page,
+ size_t num_pages)
{
down_write(&current->mm->mmap_sem);

__ipath_release_user_pages(p, num_pages, 1);
-
- current->mm->pinned_vm -= num_pages;
+ mm_munpin(start_page, num_pages * PAGE_SIZE);

up_write(&current->mm->mmap_sem);
}
@@ -186,6 +180,7 @@ void ipath_release_user_pages(struct pag
struct ipath_user_pages_work {
struct work_struct work;
struct mm_struct *mm;
+ unsigned long start_page;
unsigned long num_pages;
};

@@ -195,13 +190,15 @@ static void user_pages_account(struct wo
container_of(_work, struct ipath_user_pages_work, work);

down_write(&work->mm->mmap_sem);
- work->mm->pinned_vm -= work->num_pages;
+ mm_munpin(work->start_page, work->num_pages * PAGE_SIZE);
up_write(&work->mm->mmap_sem);
mmput(work->mm);
kfree(work);
}

-void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
+void ipath_release_user_pages_on_close(struct page **p,
+ unsigned long start_page,
+ size_t num_pages)
{
struct ipath_user_pages_work *work;
struct mm_struct *mm;
@@ -218,6 +215,7 @@ void ipath_release_user_pages_on_close(s

INIT_WORK(&work->work, user_pages_account);
work->mm = mm;
+ work->start_page = start_page;
work->num_pages = num_pages;

queue_work(ib_wq, &work->work);


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