diff options
author | Hugh Dickins <hughd@google.com> | 2023-10-19 23:39:08 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-26 02:47:16 +0300 |
commit | ddc1a5cbc05dc62743a2f409b96faa5cf95ba064 (patch) | |
tree | 6d3b7083fd984acd1391818a32ef9a7dd46049e7 /mm/zswap.c | |
parent | 23e4883248f0472d806c8b3422ba6257e67bf1a5 (diff) | |
download | linux-ddc1a5cbc05dc62743a2f409b96faa5cf95ba064.tar.xz |
mempolicy: alloc_pages_mpol() for NUMA policy without vma
Shrink shmem's stack usage by eliminating the pseudo-vma from its folio
allocation. alloc_pages_mpol(gfp, order, pol, ilx, nid) becomes the
principal actor for passing mempolicy choice down to __alloc_pages(),
rather than vma_alloc_folio(gfp, order, vma, addr, hugepage).
vma_alloc_folio() and alloc_pages() remain, but as wrappers around
alloc_pages_mpol(). alloc_pages_bulk_*() untouched, except to provide the
additional args to policy_nodemask(), which subsumes policy_node().
Cleanup throughout, cutting out some unhelpful "helpers".
It would all be much simpler without MPOL_INTERLEAVE, but that adds a
dynamic to the constant mpol: complicated by v3.6 commit 09c231cb8bfd
("tmpfs: distribute interleave better across nodes"), which added ino bias
to the interleave, hidden from mm/mempolicy.c until this commit.
Hence "ilx" throughout, the "interleave index". Originally I thought it
could be done just with nid, but that's wrong: the nodemask may come from
the shared policy layer below a shmem vma, or it may come from the task
layer above a shmem vma; and without the final nodemask then nodeid cannot
be decided. And how ilx is applied depends also on page order.
The interleave index is almost always irrelevant unless MPOL_INTERLEAVE:
with one exception in alloc_pages_mpol(), where the NO_INTERLEAVE_INDEX
passed down from vma-less alloc_pages() is also used as hint not to use
THP-style hugepage allocation - to avoid the overhead of a hugepage arg
(though I don't understand why we never just added a GFP bit for THP - if
it actually needs a different allocation strategy from other pages of the
same order). vma_alloc_folio() still carries its hugepage arg here, but
it is not used, and should be removed when agreed.
get_vma_policy() no longer allows a NULL vma: over time I believe we've
eradicated all the places which used to need it e.g. swapoff and madvise
used to pass NULL vma to read_swap_cache_async(), but now know the vma.
[hughd@google.com: handle NULL mpol being passed to __read_swap_cache_async()]
Link: https://lkml.kernel.org/r/ea419956-4751-0102-21f7-9c93cb957892@google.com
Link: https://lkml.kernel.org/r/74e34633-6060-f5e3-aee-7040d43f2e93@google.com
Link: https://lkml.kernel.org/r/1738368e-bac0-fd11-ed7f-b87142a939fe@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun heo <tj@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Domenico Cerasuolo <mimmocerasuolo@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/zswap.c')
-rw-r--r-- | mm/zswap.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index 37d2b1cb2ecb..060857adca76 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -24,6 +24,7 @@ #include <linux/swap.h> #include <linux/crypto.h> #include <linux/scatterlist.h> +#include <linux/mempolicy.h> #include <linux/mempool.h> #include <linux/zpool.h> #include <crypto/acompress.h> @@ -1057,6 +1058,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry, { swp_entry_t swpentry = entry->swpentry; struct page *page; + struct mempolicy *mpol; struct scatterlist input, output; struct crypto_acomp_ctx *acomp_ctx; struct zpool *pool = zswap_find_zpool(entry); @@ -1075,8 +1077,9 @@ static int zswap_writeback_entry(struct zswap_entry *entry, } /* try to allocate swap cache page */ - page = __read_swap_cache_async(swpentry, GFP_KERNEL, NULL, 0, - &page_was_allocated); + mpol = get_task_policy(current); + page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol, + NO_INTERLEAVE_INDEX, &page_was_allocated); if (!page) { ret = -ENOMEM; goto fail; |