FAILED: patch "[PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING" failed to apply to 5.4-stable tree

PATCH [email protected] 2 participants 5 messages Dec 9, 2020 – Dec 14, 2020

Subsystems (6)

Stable branch Memory management Arm (32-bit) MM core +2 more subsystems

lore

Share & tools

lore

[email protected]

author maintainer

2020-12-09 15:54 UTC #0 lore raw

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e91d8d78237de8d7120c320b3645b7100848f24d Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email protected]>
Date: Sat, 5 Dec 2020 22:14:51 -0800
Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING

While I was doing zram testing, I found sometimes decompression failed since the compression buffer was corrupted. With investigation, I found below commit calls cond_resched unconditionally so it could make a problem in atomic context if the task is reschedule.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:108
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog
  3 locks held by memhog/946:
   #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160
   #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160
   #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0
  CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
  Call Trace:
    unmap_kernel_range_noflush+0x2eb/0x350
    unmap_kernel_range+0x14/0x30
    zs_unmap_object+0xd5/0xe0
    zram_bvec_rw.isra.0+0x38c/0x8e0
    zram_rw_page+0x90/0x101
    bdev_write_page+0x92/0xe0
    __swap_writepage+0x94/0x4a0
    pageout+0xe3/0x3a0
    shrink_page_list+0xb94/0xd60
    shrink_inactive_list+0x158/0x460

We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which contains the offending calling code) from zsmalloc.

Even though this option showed some amount improvement(e.g., 30%) in some arm32 platforms, it has been headache to maintain since it have abused APIs[1](e.g., unmap_kernel_range in atomic context).

Since we are approaching to deprecate 32bit machines and already made the config option available for only builtin build since v5.8, lastly it has been not default option in zsmalloc, it's time to drop the option for better maintenance.

[1] http://lore.kernel.org/linux-mm/[email protected]

Fixes e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range")

Signed-off-by Minchan Kim <[email protected]>

Signed-off-by Andrew Morton <[email protected]>

Reviewed-by Sergey Senozhatsky <[email protected]>

Cc Tony Lindgren <[email protected]>

Cc Christoph Hellwig <[email protected]>

Cc Harish Sriram <[email protected]>

Cc Uladzislau Rezki <[email protected]>

Cc <[email protected]>

Link https://lkml.kernel.org/r/[email protected] open here

Signed-off-by Linus Torvalds <[email protected]>

arch/arm/configs/omap2plus_defconfig +0 -1

index 34793aabdb65..58df9fd79a76 100644
@@ -81,7 +81,6 @@ CONFIG_PARTITION_ADVANCED=y
 CONFIG_BINFMT_MISC=y
 CONFIG_CMA=y
 CONFIG_ZSMALLOC=m
-CONFIG_ZSMALLOC_PGTABLE_MAPPING=y
 CONFIG_NET=y
 CONFIG_PACKET=y
 CONFIG_UNIX=y

include/linux/zsmalloc.h +0 -1

index 0fdbf653b173..4807ca4d52e0 100644
@@ -20,7 +20,6 @@
  * zsmalloc mapping modes
  *
  * NOTE: These only make a difference when a mapped object spans pages.
- * They also have no effect when ZSMALLOC_PGTABLE_MAPPING is selected.
  */
 enum zs_mapmode {
 	ZS_MM_RW, /* normal read-write mapping */

mm/Kconfig +0 ~~-13~~

index d42423f884a7..390165ffbb0f 100644
@@ -707,19 +707,6 @@ config ZSMALLOC
 	  returned by an alloc().  This handle must be mapped in order to
 	  access the allocated space.
 
-config ZSMALLOC_PGTABLE_MAPPING
-	bool "Use page table mapping to access object in zsmalloc"
-	depends on ZSMALLOC=y
-	help
-	  By default, zsmalloc uses a copy-based object mapping method to
-	  access allocations that span two pages. However, if a particular
-	  architecture (ex, ARM) performs VM mapping faster than copying,
-	  then you should select this. This causes zsmalloc to use page table
-	  mapping rather than copying for object mapping.
-
-	  You can check speed with zsmalloc benchmark:
-	  https://github.com/spartacus06/zsmapbench
-
 config ZSMALLOC_STAT
 	bool "Export zsmalloc statistics"
 	depends on ZSMALLOC

mm/zsmalloc.c +0 ~~-54~~

73 lines not on this page · raw message

Minchan Kim

maintainer

2020-12-10 17:55 UTC #1 lore raw

Quoted 49 lines · On Wed, Dec 09, 2020 at 10:07:04AM +0100, [email protected] wrote:

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e91d8d78237de8d7120c320b3645b7100848f24d Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email protected]>
Date: Sat, 5 Dec 2020 22:14:51 -0800
Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING
While I was doing zram testing, I found sometimes decompression failed since the compression buffer was corrupted. With investigation, I found below commit calls cond_resched unconditionally so it could make a problem in atomic context if the task is reschedule.
  BUG: sleeping function called from invalid context at mm/vmalloc.c:108
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog
  3 locks held by memhog/946:
   #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160
   #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160
   #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0
  CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
  Call Trace:
    unmap_kernel_range_noflush+0x2eb/0x350
    unmap_kernel_range+0x14/0x30
    zs_unmap_object+0xd5/0xe0
    zram_bvec_rw.isra.0+0x38c/0x8e0
    zram_rw_page+0x90/0x101
    bdev_write_page+0x92/0xe0
    __swap_writepage+0x94/0x4a0
    pageout+0xe3/0x3a0
    shrink_page_list+0xb94/0xd60
    shrink_inactive_list+0x158/0x460
We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which contains the offending calling code) from zsmalloc.
Even though this option showed some amount improvement(e.g., 30%) in some arm32 platforms, it has been headache to maintain since it have abused APIs[1](e.g., unmap_kernel_range in atomic context).

Quoted 8 lines

Since we are approaching to deprecate 32bit machines and already made the config option available for only builtin build since v5.8, lastly it has been not default option in zsmalloc, it's time to drop the option for better maintenance.
[1] http://lore.kernel.org/linux-mm/[email protected]
Fixes e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range")

This patch fixex e47110e90584 which merged at v5.9 so we could drop it for v5.4.

Thanks.

Greg KH

author maintainer

2020-12-11 15:41 UTC #2 lore raw

Quoted 55 lines · Minchan Kim

Quoted 54 lines · On Wed, Dec 09, 2020 at 10:07:04AM +0100, [email protected] wrote:
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e91d8d78237de8d7120c320b3645b7100848f24d Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email protected]>
Date: Sat, 5 Dec 2020 22:14:51 -0800
Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING
While I was doing zram testing, I found sometimes decompression failed since the compression buffer was corrupted. With investigation, I found below commit calls cond_resched unconditionally so it could make a problem in atomic context if the task is reschedule.
  BUG: sleeping function called from invalid context at mm/vmalloc.c:108
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog
  3 locks held by memhog/946:
   #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160
   #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160
   #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0
  CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
  Call Trace:
    unmap_kernel_range_noflush+0x2eb/0x350
    unmap_kernel_range+0x14/0x30
    zs_unmap_object+0xd5/0xe0
    zram_bvec_rw.isra.0+0x38c/0x8e0
    zram_rw_page+0x90/0x101
    bdev_write_page+0x92/0xe0
    __swap_writepage+0x94/0x4a0
    pageout+0xe3/0x3a0
    shrink_page_list+0xb94/0xd60
    shrink_inactive_list+0x158/0x460
We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which contains the offending calling code) from zsmalloc.
Even though this option showed some amount improvement(e.g., 30%) in some arm32 platforms, it has been headache to maintain since it have abused APIs[1](e.g., unmap_kernel_range in atomic context).
Since we are approaching to deprecate 32bit machines and already made the config option available for only builtin build since v5.8, lastly it has been not default option in zsmalloc, it's time to drop the option for better maintenance.

Quoted 6 lines

Quoted 3 lines
[1] http://lore.kernel.org/linux-mm/[email protected]
Fixes e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range")
This patch fixex e47110e90584 which merged at v5.9 so we could drop it for v5.4.

It was backported to 5.4.62, so are you _sure_?

thanks,

greg k-h

Minchan Kim

maintainer Reviewed-by Sergey Senozhatsky

2020-12-11 23:37 UTC #3 lore raw

Quoted 56 lines · Greg KH

Quoted 55 lines · Minchan Kim
Quoted 54 lines · On Wed, Dec 09, 2020 at 10:07:04AM +0100, [email protected] wrote:
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e91d8d78237de8d7120c320b3645b7100848f24d Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email protected]>
Date: Sat, 5 Dec 2020 22:14:51 -0800
Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING
While I was doing zram testing, I found sometimes decompression failed since the compression buffer was corrupted. With investigation, I found below commit calls cond_resched unconditionally so it could make a problem in atomic context if the task is reschedule.
  BUG: sleeping function called from invalid context at mm/vmalloc.c:108
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog
  3 locks held by memhog/946:
   #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160
   #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160
   #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0
  CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
  Call Trace:
    unmap_kernel_range_noflush+0x2eb/0x350
    unmap_kernel_range+0x14/0x30
    zs_unmap_object+0xd5/0xe0
    zram_bvec_rw.isra.0+0x38c/0x8e0
    zram_rw_page+0x90/0x101
    bdev_write_page+0x92/0xe0
    __swap_writepage+0x94/0x4a0
    pageout+0xe3/0x3a0
    shrink_page_list+0xb94/0xd60
    shrink_inactive_list+0x158/0x460
We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which contains the offending calling code) from zsmalloc.
Even though this option showed some amount improvement(e.g., 30%) in some arm32 platforms, it has been headache to maintain since it have abused APIs[1](e.g., unmap_kernel_range in atomic context).
Since we are approaching to deprecate 32bit machines and already made the config option available for only builtin build since v5.8, lastly it has been not default option in zsmalloc, it's time to drop the option for better maintenance.

Quoted 8 lines

Quoted 6 lines
Quoted 3 lines
[1] http://lore.kernel.org/linux-mm/[email protected]
Fixes e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range")
This patch fixex e47110e90584 which merged at v5.9 so we could drop it for v5.4.
It was backported to 5.4.62, so are you _sure_?

Oops, the patch went into 5.4 as stable but missed it. This is backport patch for 5.4.
original commit id is e91d8d78237de8d7120c320b3645b7100848f24d

Let me know unless it applies clean
Thank you!

From 29a6ece5ade445d776a58ff1a54ed50ed126fa70 Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email protected]>
Date: Sat, 5 Dec 2020 22:14:51 -0800
Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING

  BUG: sleeping function called from invalid context at mm/vmalloc.c:108
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog
  3 locks held by memhog/946:
   #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160
   #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160
   #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0
  CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
  Call Trace:
    unmap_kernel_range_noflush+0x2eb/0x350
    unmap_kernel_range+0x14/0x30
    zs_unmap_object+0xd5/0xe0
    zram_bvec_rw.isra.0+0x38c/0x8e0
    zram_rw_page+0x90/0x101
    bdev_write_page+0x92/0xe0
    __swap_writepage+0x94/0x4a0
    pageout+0xe3/0x3a0
    shrink_page_list+0xb94/0xd60
    shrink_inactive_list+0x158/0x460

We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which contains the offending calling code) from zsmalloc.

[1] http://lore.kernel.org/linux-mm/[email protected]

Fixes e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range")

Signed-off-by Minchan Kim <[email protected]>

Signed-off-by Andrew Morton <[email protected]>

Reviewed-by Sergey Senozhatsky <[email protected]>

Cc Tony Lindgren <[email protected]>

Cc Christoph Hellwig <[email protected]>

Cc Harish Sriram <[email protected]>

Cc Uladzislau Rezki <[email protected]>

Cc <[email protected]>

Link https://lkml.kernel.org/r/[email protected] open here

Signed-off-by Linus Torvalds <[email protected]>

---
 include/linux/zsmalloc.h |  1 -
 mm/Kconfig               | 13 ------------
 mm/zsmalloc.c            | 46 ----------------------------------------
 3 files changed, 60 deletions(-)

include/linux/zsmalloc.h +0 -1

index 2219cce81ca4..4807ca4d52e0 100644
@@ -20,7 +20,6 @@
  * zsmalloc mapping modes
  *
  * NOTE: These only make a difference when a mapped object spans pages.
- * They also have no effect when PGTABLE_MAPPING is selected.
  */
 enum zs_mapmode {
 	ZS_MM_RW, /* normal read-write mapping */

mm/Kconfig +0 ~~-13~~

index a5dae9a7eb51..fbdc5c70e487 100644
@@ -576,19 +576,6 @@ config ZSMALLOC
 	  returned by an alloc().  This handle must be mapped in order to
 	  access the allocated space.
 
-config PGTABLE_MAPPING
-	bool "Use page table mapping to access object in zsmalloc"
-	depends on ZSMALLOC
-	help
-	  By default, zsmalloc uses a copy-based object mapping method to
-	  access allocations that span two pages. However, if a particular
-	  architecture (ex, ARM) performs VM mapping faster than copying,
-	  then you should select this. This causes zsmalloc to use page table
-	  mapping rather than copying for object mapping.
-
-	  You can check speed with zsmalloc benchmark:
-	  https://github.com/spartacus06/zsmapbench
-
 config ZSMALLOC_STAT
 	bool "Export zsmalloc statistics"
 	depends on ZSMALLOC

mm/zsmalloc.c +0 ~~-46~~

65 lines not on this page · raw message

Signature · 1 line

2.29.2.576.ga3fc446d84-goog

Greg KH

author maintainer

2020-12-14 15:47 UTC #4 lore raw

Quoted 64 lines · Minchan Kim

Quoted 63 lines · Greg KH
Quoted 61 lines · Minchan Kim
Quoted 49 lines · On Wed, Dec 09, 2020 at 10:07:04AM +0100, [email protected] wrote:
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e91d8d78237de8d7120c320b3645b7100848f24d Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email protected]>
Date: Sat, 5 Dec 2020 22:14:51 -0800
Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING
While I was doing zram testing, I found sometimes decompression failed since the compression buffer was corrupted. With investigation, I found below commit calls cond_resched unconditionally so it could make a problem in atomic context if the task is reschedule.
  BUG: sleeping function called from invalid context at mm/vmalloc.c:108
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog
  3 locks held by memhog/946:
   #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160
   #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160
   #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0
  CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
  Call Trace:
    unmap_kernel_range_noflush+0x2eb/0x350
    unmap_kernel_range+0x14/0x30
    zs_unmap_object+0xd5/0xe0
    zram_bvec_rw.isra.0+0x38c/0x8e0
    zram_rw_page+0x90/0x101
    bdev_write_page+0x92/0xe0
    __swap_writepage+0x94/0x4a0
    pageout+0xe3/0x3a0
    shrink_page_list+0xb94/0xd60
    shrink_inactive_list+0x158/0x460
We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which contains the offending calling code) from zsmalloc.
Even though this option showed some amount improvement(e.g., 30%) in some arm32 platforms, it has been headache to maintain since it have abused APIs[1](e.g., unmap_kernel_range in atomic context).
Quoted 8 lines
Since we are approaching to deprecate 32bit machines and already made the config option available for only builtin build since v5.8, lastly it has been not default option in zsmalloc, it's time to drop the option for better maintenance.
[1] http://lore.kernel.org/linux-mm/[email protected]
Fixes e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range")
This patch fixex e47110e90584 which merged at v5.9 so we could drop it for v5.4.

Quoted 7 lines

Quoted 1 line
It was backported to 5.4.62, so are you _sure_?
Oops, the patch went into 5.4 as stable but missed it. This is backport patch for 5.4.
original commit id is e91d8d78237de8d7120c320b3645b7100848f24d
Let me know unless it applies clean

That worked, thanks!

greg k-h