The patch titled
Subject: mm/shuffle: Fix shuffle enable
has been added to the -mm tree. Its filename is
mm-shuffle-initial-free-memory-to-improve-memory-side-cache-utilization-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-shuffle-initial-free-memory-to-improve-memory-side-cache-utilization-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-shuffle-initial-free-memory-to-improve-memory-side-cache-utilization-fix.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** 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: Dan Williams <dan.j.williams@xxxxxxxxx>
Subject: mm/shuffle: Fix shuffle enable
The removal of shuffle_store() in v10 of the patch series was prompted by
the review feedback to convert page_alloc_shuffle() to __memint. I
obviously booted a stale kernel build in my tests because shuffle_store()
is indeed required:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
#PF error: [INSTR]
PGD 0 P4D 0
Oops: 0010 [#1] SMP PTI
CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc1+ #2867
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180531_142017-buildhw-08.phx2.fedoraproject.org-1.fc28 04/01/2014
RIP: 0010: (null)
Code: Bad RIP value.
RSP: 0000:ffffffff82603e78 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: cccccccccccccccd
RDX: ffffffff8261d7c0 RSI: ffffffff8244c010 RDI: ffff88843ffe1aaa
RBP: ffff88843ffe1aac R08: ffffffff83486978 R09: 0000000000000000
R10: ffffffff82603e80 R11: 0000000000000048 R12: ffff88843ffe1a97
R13: ffff88843ffe1aaa R14: ffffffff8244c010 R15: 000000000000016d
FS: 0000000000000000(0000) GS:ffff88811be00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000002614000 CR4: 00000000000606b0
Call Trace:
? parse_args+0x170/0x360
? set_init_arg+0x55/0x55
? start_kernel+0x1d8/0x4c4
? set_init_arg+0x55/0x55
? secondary_startup_64+0xa4/0xb0
Reintroduce it and mark it __meminit. Given the sysfs attribute is not
writable it will never be called after init.
Link: http://lkml.kernel.org/r/154943713038.3858443.4125180191382062871.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/shuffle.c~mm-shuffle-initial-free-memory-to-improve-memory-side-cache-utilization-fix
+++ a/mm/shuffle.c
@@ -38,7 +38,21 @@ extern int shuffle_show(char *buffer, co
return sprintf(buffer, "%c\n", test_bit(SHUFFLE_ENABLE, &shuffle_state)
? 'Y' : 'N');
}
-module_param_call(shuffle, NULL, shuffle_show, &shuffle_param, 0400);
+
+static __meminit int shuffle_store(const char *val,
+ const struct kernel_param *kp)
+{
+ int rc = param_set_bool(val, kp);
+
+ if (rc < 0)
+ return rc;
+ if (shuffle_param)
+ page_alloc_shuffle(SHUFFLE_ENABLE);
+ else
+ page_alloc_shuffle(SHUFFLE_FORCE_DISABLE);
+ return 0;
+}
+module_param_call(shuffle, shuffle_store, shuffle_show, &shuffle_param, 0400);
/*
* For two pages to be swapped in the shuffle, they must be free (on a
_
Patches currently in -mm which might be from dan.j.williams@xxxxxxxxx are
mm-shuffle-initial-free-memory-to-improve-memory-side-cache-utilization.patch
mm-shuffle-initial-free-memory-to-improve-memory-side-cache-utilization-fix.patch
mm-move-buddy-list-manipulations-into-helpers.patch
mm-maintain-randomization-of-page-free-lists.patch
