diff options
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/rdma/hfi1/hfi.h | 1 | ||||
| -rw-r--r-- | drivers/staging/rdma/hfi1/user_pages.c | 52 |
2 files changed, 47 insertions, 6 deletions
diff --git a/drivers/staging/rdma/hfi1/hfi.h b/drivers/staging/rdma/hfi1/hfi.h index 2107cdc8ce3f..ff3b37ad89a3 100644 --- a/drivers/staging/rdma/hfi1/hfi.h +++ b/drivers/staging/rdma/hfi1/hfi.h @@ -1664,6 +1664,7 @@ void shutdown_led_override(struct hfi1_pportdata *ppd); */ #define DEFAULT_RCVHDR_ENTSIZE 32 +bool hfi1_can_pin_pages(struct hfi1_devdata *, u32, u32); int hfi1_acquire_user_pages(unsigned long, size_t, bool, struct page **); void hfi1_release_user_pages(struct page **, size_t, bool); diff --git a/drivers/staging/rdma/hfi1/user_pages.c b/drivers/staging/rdma/hfi1/user_pages.c index 3bf81086c24d..bd7a8ab0d635 100644 --- a/drivers/staging/rdma/hfi1/user_pages.c +++ b/drivers/staging/rdma/hfi1/user_pages.c @@ -48,22 +48,62 @@ #include <linux/mm.h> #include <linux/sched.h> #include <linux/device.h> +#include <linux/module.h> #include "hfi.h" -int hfi1_acquire_user_pages(unsigned long vaddr, size_t npages, bool writable, - struct page **pages) +static unsigned long cache_size = 256; +module_param(cache_size, ulong, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(cache_size, "Send and receive side cache size limit (in MB)"); + +/* + * Determine whether the caller can pin pages. + * + * This function should be used in the implementation of buffer caches. + * The cache implementation should call this function prior to attempting + * to pin buffer pages in order to determine whether they should do so. + * The function computes cache limits based on the configured ulimit and + * cache size. Use of this function is especially important for caches + * which are not limited in any other way (e.g. by HW resources) and, thus, + * could keeping caching buffers. + * + */ +bool hfi1_can_pin_pages(struct hfi1_devdata *dd, u32 nlocked, u32 npages) { - unsigned long pinned, lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + unsigned long ulimit = rlimit(RLIMIT_MEMLOCK), pinned, cache_limit, + size = (cache_size * (1UL << 20)); /* convert to bytes */ + unsigned usr_ctxts = dd->num_rcv_contexts - dd->first_user_ctxt; bool can_lock = capable(CAP_IPC_LOCK); - int ret; + + /* + * Calculate per-cache size. The calculation below uses only a quarter + * of the available per-context limit. This leaves space for other + * pinning. Should we worry about shared ctxts? + */ + cache_limit = (ulimit / usr_ctxts) / 4; + + /* If ulimit isn't set to "unlimited" and is smaller than cache_size. */ + if (ulimit != (-1UL) && size > cache_limit) + size = cache_limit; + + /* Convert to number of pages */ + size = DIV_ROUND_UP(size, PAGE_SIZE); down_read(¤t->mm->mmap_sem); pinned = current->mm->pinned_vm; up_read(¤t->mm->mmap_sem); - if (pinned + npages > lock_limit && !can_lock) - return -ENOMEM; + /* First, check the absolute limit against all pinned pages. */ + if (pinned + npages >= ulimit && !can_lock) + return false; + + return ((nlocked + npages) <= size) || can_lock; +} + +int hfi1_acquire_user_pages(unsigned long vaddr, size_t npages, bool writable, + struct page **pages) +{ + int ret; ret = get_user_pages_fast(vaddr, npages, writable, pages); if (ret < 0) |