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* + mm-zswap-cleanup-zswap_writeback_entry.patch added to mm-unstable branch
@ 2023-12-18 17:09 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2023-12-18 17:09 UTC (permalink / raw)
  To: mm-commits, yosryahmed, vitaly.wool, sjenning, nphamcs, hannes,
	ddstreet, chrisl, zhouchengming, akpm


The patch titled
     Subject: mm/zswap: cleanup zswap_writeback_entry()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-zswap-cleanup-zswap_writeback_entry.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-cleanup-zswap_writeback_entry.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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 via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Chengming Zhou <zhouchengming@bytedance.com>
Subject: mm/zswap: cleanup zswap_writeback_entry()
Date: Mon, 18 Dec 2023 11:50:35 +0000

Also after the common decompress part goes to __zswap_load(), we can
cleanup the zswap_writeback_entry() a little.

Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v3-5-4eac09b94ece@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/zswap.c |   25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

--- a/mm/zswap.c~mm-zswap-cleanup-zswap_writeback_entry
+++ a/mm/zswap.c
@@ -1443,7 +1443,6 @@ static int zswap_writeback_entry(struct
 	struct page *page;
 	struct mempolicy *mpol;
 	bool page_was_allocated;
-	int ret;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_NONE,
 	};
@@ -1453,15 +1452,18 @@ static int zswap_writeback_entry(struct
 	page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
 				NO_INTERLEAVE_INDEX, &page_was_allocated, true);
 	if (!page) {
-		ret = -ENOMEM;
-		goto fail;
+		/*
+		 * If we get here because the page is already in swapcache, a
+		 * load may be happening concurrently. It is safe and okay to
+		 * not free the entry. It is also okay to return !0.
+		 */
+		return -ENOMEM;
 	}
 
 	/* Found an existing page, we raced with load/swapin */
 	if (!page_was_allocated) {
 		put_page(page);
-		ret = -EEXIST;
-		goto fail;
+		return -EEXIST;
 	}
 
 	/*
@@ -1475,8 +1477,7 @@ static int zswap_writeback_entry(struct
 	if (zswap_rb_search(&tree->rbroot, swp_offset(entry->swpentry)) != entry) {
 		spin_unlock(&tree->lock);
 		delete_from_swap_cache(page_folio(page));
-		ret = -ENOMEM;
-		goto fail;
+		return -ENOMEM;
 	}
 	spin_unlock(&tree->lock);
 
@@ -1492,15 +1493,7 @@ static int zswap_writeback_entry(struct
 	__swap_writepage(page, &wbc);
 	put_page(page);
 
-	return ret;
-
-fail:
-	/*
-	 * If we get here because the page is already in swapcache, a
-	 * load may be happening concurrently. It is safe and okay to
-	 * not free the entry. It is also okay to return !0.
-	 */
-	return ret;
+	return 0;
 }
 
 static int zswap_is_page_same_filled(void *ptr, unsigned long *value)
_

Patches currently in -mm which might be from zhouchengming@bytedance.com are

mm-zswap-change-dstmem-size-to-one-page.patch
mm-zswap-reuse-dstmem-when-decompress.patch
mm-zswap-refactor-out-__zswap_load.patch
mm-zswap-cleanup-zswap_load.patch
mm-zswap-cleanup-zswap_writeback_entry.patch
mm-zswap-directly-use-percpu-mutex-and-buffer-in-load-store.patch


^ permalink raw reply	[flat|nested] 3+ messages in thread
* + mm-zswap-cleanup-zswap_writeback_entry.patch added to mm-unstable branch
@ 2023-12-26 19:51 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2023-12-26 19:51 UTC (permalink / raw)
  To: mm-commits, yosryahmed, vitaly.wool, sjenning, nphamcs, hannes,
	ddstreet, chrisl, zhouchengming, akpm


The patch titled
     Subject: mm/zswap: cleanup zswap_writeback_entry()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-zswap-cleanup-zswap_writeback_entry.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-cleanup-zswap_writeback_entry.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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 via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Chengming Zhou <zhouchengming@bytedance.com>
Subject: mm/zswap: cleanup zswap_writeback_entry()
Date: Tue, 26 Dec 2023 15:54:12 +0000

Also after the common decompress part goes to __zswap_load(), we can
cleanup the zswap_writeback_entry() a little.

Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v4-5-f228b059dd89@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Chris Li <chrisl@kernel.org> (Google)
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/zswap.c |   29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

--- a/mm/zswap.c~mm-zswap-cleanup-zswap_writeback_entry
+++ a/mm/zswap.c
@@ -1443,7 +1443,6 @@ static int zswap_writeback_entry(struct
 	struct page *page;
 	struct mempolicy *mpol;
 	bool page_was_allocated;
-	int ret;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_NONE,
 	};
@@ -1452,16 +1451,17 @@ static int zswap_writeback_entry(struct
 	mpol = get_task_policy(current);
 	page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
 				NO_INTERLEAVE_INDEX, &page_was_allocated, true);
-	if (!page) {
-		ret = -ENOMEM;
-		goto fail;
-	}
+	if (!page)
+		return -ENOMEM;
 
-	/* Found an existing page, we raced with load/swapin */
+	/*
+	 * Found an existing page, we raced with load/swapin. We generally
+	 * writeback cold pages from zswap, and swapin means the page just
+	 * became hot. Skip this page and let the caller find another one.
+	 */
 	if (!page_was_allocated) {
 		put_page(page);
-		ret = -EEXIST;
-		goto fail;
+		return -EEXIST;
 	}
 
 	/*
@@ -1475,8 +1475,7 @@ static int zswap_writeback_entry(struct
 	if (zswap_rb_search(&tree->rbroot, swp_offset(entry->swpentry)) != entry) {
 		spin_unlock(&tree->lock);
 		delete_from_swap_cache(page_folio(page));
-		ret = -ENOMEM;
-		goto fail;
+		return -ENOMEM;
 	}
 	spin_unlock(&tree->lock);
 
@@ -1492,15 +1491,7 @@ static int zswap_writeback_entry(struct
 	__swap_writepage(page, &wbc);
 	put_page(page);
 
-	return ret;
-
-fail:
-	/*
-	 * If we get here because the page is already in swapcache, a
-	 * load may be happening concurrently. It is safe and okay to
-	 * not free the entry. It is also okay to return !0.
-	 */
-	return ret;
+	return 0;
 }
 
 static int zswap_is_page_same_filled(void *ptr, unsigned long *value)
_

Patches currently in -mm which might be from zhouchengming@bytedance.com are

mm-zswap-change-dstmem-size-to-one-page.patch
mm-zswap-reuse-dstmem-when-decompress.patch
mm-zswap-refactor-out-__zswap_load.patch
mm-zswap-cleanup-zswap_load.patch
mm-zswap-cleanup-zswap_writeback_entry.patch
mm-zswap-change-per-cpu-mutex-and-buffer-to-per-acomp_ctx.patch


^ permalink raw reply	[flat|nested] 3+ messages in thread
* + mm-zswap-cleanup-zswap_writeback_entry.patch added to mm-unstable branch
@ 2023-12-28 18:32 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2023-12-28 18:32 UTC (permalink / raw)
  To: mm-commits, yosryahmed, vitaly.wool, sjenning, nphamcs, hannes,
	ddstreet, chrisl, 21cnbao, zhouchengming, akpm


The patch titled
     Subject: mm/zswap: cleanup zswap_writeback_entry()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-zswap-cleanup-zswap_writeback_entry.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-cleanup-zswap_writeback_entry.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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 via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Chengming Zhou <zhouchengming@bytedance.com>
Subject: mm/zswap: cleanup zswap_writeback_entry()
Date: Thu, 28 Dec 2023 09:45:45 +0000

Also after the common decompress part goes to __zswap_load(), we can
cleanup the zswap_writeback_entry() a little.

Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-4-9382162bbf05@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Chris Li <chrisl@kernel.org> (Google)
Cc: Barry Song <21cnbao@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/zswap.c |   29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

--- a/mm/zswap.c~mm-zswap-cleanup-zswap_writeback_entry
+++ a/mm/zswap.c
@@ -1443,7 +1443,6 @@ static int zswap_writeback_entry(struct
 	struct page *page;
 	struct mempolicy *mpol;
 	bool page_was_allocated;
-	int ret;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_NONE,
 	};
@@ -1452,16 +1451,17 @@ static int zswap_writeback_entry(struct
 	mpol = get_task_policy(current);
 	page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
 				NO_INTERLEAVE_INDEX, &page_was_allocated, true);
-	if (!page) {
-		ret = -ENOMEM;
-		goto fail;
-	}
+	if (!page)
+		return -ENOMEM;
 
-	/* Found an existing page, we raced with load/swapin */
+	/*
+	 * Found an existing page, we raced with load/swapin. We generally
+	 * writeback cold pages from zswap, and swapin means the page just
+	 * became hot. Skip this page and let the caller find another one.
+	 */
 	if (!page_was_allocated) {
 		put_page(page);
-		ret = -EEXIST;
-		goto fail;
+		return -EEXIST;
 	}
 
 	/*
@@ -1475,8 +1475,7 @@ static int zswap_writeback_entry(struct
 	if (zswap_rb_search(&tree->rbroot, swp_offset(entry->swpentry)) != entry) {
 		spin_unlock(&tree->lock);
 		delete_from_swap_cache(page_folio(page));
-		ret = -ENOMEM;
-		goto fail;
+		return -ENOMEM;
 	}
 	spin_unlock(&tree->lock);
 
@@ -1492,15 +1491,7 @@ static int zswap_writeback_entry(struct
 	__swap_writepage(page, &wbc);
 	put_page(page);
 
-	return ret;
-
-fail:
-	/*
-	 * If we get here because the page is already in swapcache, a
-	 * load may be happening concurrently. It is safe and okay to
-	 * not free the entry. It is also okay to return !0.
-	 */
-	return ret;
+	return 0;
 }
 
 static int zswap_is_page_same_filled(void *ptr, unsigned long *value)
_

Patches currently in -mm which might be from zhouchengming@bytedance.com are

mm-zswap-reuse-dstmem-when-decompress.patch
mm-zswap-refactor-out-__zswap_load.patch
mm-zswap-cleanup-zswap_load.patch
mm-zswap-cleanup-zswap_writeback_entry.patch
mm-zswap-change-per-cpu-mutex-and-buffer-to-per-acomp_ctx.patch


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-12-28 18:32 UTC | newest]

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