From: Chunhai Guo via Linux-erofs <linux-erofs@lists.ozlabs.org>
To: xiang@kernel.org
Cc: Chunhai Guo <guochunhai@vivo.com>,
linux-erofs@lists.ozlabs.org, huyue2@coolpad.com
Subject: [PATCH v2] erofs: relaxed temporary buffers allocation on readahead
Date: Sat, 20 Jan 2024 07:55:51 -0700 [thread overview]
Message-ID: <20240120145551.1941483-1-guochunhai@vivo.com> (raw)
Even with inplace decompression, sometimes extra temporary buffers are
still needed for decompression. In low-memory scenarios, it would be
better to try to allocate with GFP_NOWAIT on readahead first. That can
help reduce the time spent on page allocation under memory pressure.
There is an average reduction of 21% in page allocation time under
multi-app launch benchmark workload [1] on ARM64 Android devices running
the 5.15 kernel with an 8-core CPU and 8GB of memory.
[1] https://lore.kernel.org/r/20240109074143.4138783-1-guochunhai@vivo.com
Suggested-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
---
fs/erofs/compress.h | 5 ++---
fs/erofs/decompressor.c | 5 +++--
fs/erofs/decompressor_deflate.c | 19 +++++++++++++------
fs/erofs/decompressor_lzma.c | 17 ++++++++++++-----
fs/erofs/zdata.c | 16 ++++++++++++----
5 files changed, 42 insertions(+), 20 deletions(-)
diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
index 279933e007d2..7cc5841577b2 100644
--- a/fs/erofs/compress.h
+++ b/fs/erofs/compress.h
@@ -11,13 +11,12 @@
struct z_erofs_decompress_req {
struct super_block *sb;
struct page **in, **out;
-
unsigned short pageofs_in, pageofs_out;
unsigned int inputsize, outputsize;
- /* indicate the algorithm will be used for decompression */
- unsigned int alg;
+ unsigned int alg; /* the algorithm for decompression */
bool inplace_io, partial_decoding, fillgaps;
+ gfp_t gfp; /* allocation flags for extra temporary buffers */
};
struct z_erofs_decompressor {
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 1d65b9f60a39..ef2b08ec9830 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -111,8 +111,9 @@ static int z_erofs_lz4_prepare_dstpages(struct z_erofs_lz4_decompress_ctx *ctx,
victim = availables[--top];
get_page(victim);
} else {
- victim = erofs_allocpage(pagepool,
- GFP_KERNEL | __GFP_NOFAIL);
+ victim = erofs_allocpage(pagepool, rq->gfp);
+ if (!victim)
+ return -ENOMEM;
set_page_private(victim, Z_EROFS_SHORTLIVED_PAGE);
}
rq->out[i] = victim;
diff --git a/fs/erofs/decompressor_deflate.c b/fs/erofs/decompressor_deflate.c
index 4a64a9c91dd3..b98872058abe 100644
--- a/fs/erofs/decompressor_deflate.c
+++ b/fs/erofs/decompressor_deflate.c
@@ -95,7 +95,7 @@ int z_erofs_load_deflate_config(struct super_block *sb,
}
int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
- struct page **pagepool)
+ struct page **pgpl)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -158,8 +158,12 @@ int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
strm->z.avail_out = min_t(u32, outsz, PAGE_SIZE - pofs);
outsz -= strm->z.avail_out;
if (!rq->out[no]) {
- rq->out[no] = erofs_allocpage(pagepool,
- GFP_KERNEL | __GFP_NOFAIL);
+ rq->out[no] = erofs_allocpage(pgpl, rq->gfp);
+ if (!rq->out[no]) {
+ kout = NULL;
+ err = -ENOMEM;
+ break;
+ }
set_page_private(rq->out[no],
Z_EROFS_SHORTLIVED_PAGE);
}
@@ -211,8 +215,11 @@ int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
DBG_BUGON(erofs_page_is_managed(EROFS_SB(sb),
rq->in[j]));
- tmppage = erofs_allocpage(pagepool,
- GFP_KERNEL | __GFP_NOFAIL);
+ tmppage = erofs_allocpage(pgpl, rq->gfp);
+ if (!tmppage) {
+ err = -ENOMEM;
+ goto failed;
+ }
set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE);
copy_highpage(tmppage, rq->in[j]);
rq->in[j] = tmppage;
@@ -230,7 +237,7 @@ int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
break;
}
}
-
+failed:
if (zlib_inflateEnd(&strm->z) != Z_OK && !err)
err = -EIO;
if (kout)
diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
index 2dd14f99c1dc..6ca357d83cfa 100644
--- a/fs/erofs/decompressor_lzma.c
+++ b/fs/erofs/decompressor_lzma.c
@@ -148,7 +148,7 @@ int z_erofs_load_lzma_config(struct super_block *sb,
}
int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
- struct page **pagepool)
+ struct page **pgpl)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -215,8 +215,11 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
PAGE_SIZE - pageofs);
outlen -= strm->buf.out_size;
if (!rq->out[no] && rq->fillgaps) { /* deduped */
- rq->out[no] = erofs_allocpage(pagepool,
- GFP_KERNEL | __GFP_NOFAIL);
+ rq->out[no] = erofs_allocpage(pgpl, rq->gfp);
+ if (!rq->out[no]) {
+ err = -ENOMEM;
+ break;
+ }
set_page_private(rq->out[no],
Z_EROFS_SHORTLIVED_PAGE);
}
@@ -258,8 +261,11 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
DBG_BUGON(erofs_page_is_managed(EROFS_SB(rq->sb),
rq->in[j]));
- tmppage = erofs_allocpage(pagepool,
- GFP_KERNEL | __GFP_NOFAIL);
+ tmppage = erofs_allocpage(pgpl, rq->gfp);
+ if (!tmppage) {
+ err = -ENOMEM;
+ goto failed;
+ }
set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE);
copy_highpage(tmppage, rq->in[j]);
rq->in[j] = tmppage;
@@ -277,6 +283,7 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
break;
}
}
+failed:
if (no < nrpages_out && strm->buf.out)
kunmap(rq->out[no]);
if (ni < nrpages_in)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 692c0c39be63..a293de2a60ed 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -82,6 +82,9 @@ struct z_erofs_pcluster {
/* L: indicate several pageofs_outs or not */
bool multibases;
+ /* L: whether extra buffer allocations are best-effort */
+ bool besteffort;
+
/* A: compressed bvecs (can be cached or inplaced pages) */
struct z_erofs_bvec compressed_bvecs[];
};
@@ -964,7 +967,7 @@ static int z_erofs_read_fragment(struct super_block *sb, struct page *page,
}
static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
- struct page *page)
+ struct page *page, bool ra)
{
struct inode *const inode = fe->inode;
struct erofs_map_blocks *const map = &fe->map;
@@ -1014,6 +1017,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
err = z_erofs_pcluster_begin(fe);
if (err)
goto out;
+ fe->pcl->besteffort |= !ra;
}
/*
@@ -1280,7 +1284,11 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
.inplace_io = overlapped,
.partial_decoding = pcl->partial,
.fillgaps = pcl->multibases,
+ .gfp = pcl->besteffort ?
+ GFP_KERNEL | __GFP_NOFAIL :
+ GFP_NOWAIT | __GFP_NORETRY
}, be->pagepool);
+ pcl->besteffort = false;
/* must handle all compressed pages before actual file pages */
if (z_erofs_is_inline_pcluster(pcl)) {
@@ -1785,7 +1793,7 @@ static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
if (PageUptodate(page))
unlock_page(page);
else
- (void)z_erofs_do_read_page(f, page);
+ (void)z_erofs_do_read_page(f, page, !!rac);
put_page(page);
}
@@ -1806,7 +1814,7 @@ static int z_erofs_read_folio(struct file *file, struct folio *folio)
f.headoffset = (erofs_off_t)folio->index << PAGE_SHIFT;
z_erofs_pcluster_readmore(&f, NULL, true);
- err = z_erofs_do_read_page(&f, &folio->page);
+ err = z_erofs_do_read_page(&f, &folio->page, false);
z_erofs_pcluster_readmore(&f, NULL, false);
z_erofs_pcluster_end(&f);
@@ -1847,7 +1855,7 @@ static void z_erofs_readahead(struct readahead_control *rac)
folio = head;
head = folio_get_private(folio);
- err = z_erofs_do_read_page(&f, &folio->page);
+ err = z_erofs_do_read_page(&f, &folio->page, true);
if (err && err != -EINTR)
erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu",
folio->index, EROFS_I(inode)->nid);
--
2.25.1
next reply other threads:[~2024-01-20 14:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-20 14:55 Chunhai Guo via Linux-erofs [this message]
2024-01-22 2:07 ` [PATCH v2] erofs: relaxed temporary buffers allocation on readahead Gao Xiang
2024-01-22 3:49 ` Chunhai Guo via Linux-erofs
2024-01-22 4:37 ` Gao Xiang
2024-01-22 7:42 ` Chunhai Guo via Linux-erofs
2024-01-26 2:41 ` Chunhai Guo via Linux-erofs
2024-01-26 2:47 ` Gao Xiang
2024-01-26 3:42 ` Chunhai Guo via Linux-erofs
2024-01-26 3:49 ` Gao Xiang
2024-01-26 3:56 ` 答复: " Chunhai Guo via Linux-erofs
2024-01-26 5:36 ` [PATCH v3] " Gao Xiang
2024-01-26 10:46 ` Yue Hu
2024-01-26 13:30 ` Gao Xiang
2024-01-26 14:01 ` [PATCH v4] " Gao Xiang
2024-01-27 1:49 ` Yue Hu
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