From: Barry Song <21cnbao@gmail.com>
To: herbert@gondor.apana.org.au, davem@davemloft.net,
zhouchengming@bytedance.com, linux-crypto@vger.kernel.org
Cc: akpm@linux-foundation.org, chriscli@google.com,
chrisl@kernel.org, ddstreet@ieee.org, hannes@cmpxchg.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
nphamcs@gmail.com, sjenning@redhat.com, vitaly.wool@konsulko.com,
yosryahmed@google.com, Barry Song <v-songbaohua@oppo.com>
Subject: [PATCH RFC] crypto: scompress: remove memcpy if sg_nents is 1
Date: Wed, 3 Jan 2024 18:31:34 +1300 [thread overview]
Message-ID: <20240103053134.564457-1-21cnbao@gmail.com> (raw)
In-Reply-To: <5aff3bcf-ef36-45b3-8ac0-a4b19697419c@bytedance.com>
From: Barry Song <v-songbaohua@oppo.com>
while sg_nents is 1, which is always true for the current kernel
as the only user - zswap is the case, we should be able to drop
these two big memcpy.
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
---
crypto/scompress.c | 35 ++++++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 7 deletions(-)
diff --git a/crypto/scompress.c b/crypto/scompress.c
index 442a82c9de7d..d1bb40ef83a2 100644
--- a/crypto/scompress.c
+++ b/crypto/scompress.c
@@ -117,6 +117,7 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
struct crypto_scomp *scomp = *tfm_ctx;
void **ctx = acomp_request_ctx(req);
struct scomp_scratch *scratch;
+ void *src, *dst;
int ret;
if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
@@ -131,13 +132,26 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
scratch = raw_cpu_ptr(&scomp_scratch);
spin_lock(&scratch->lock);
- scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);
+ if (sg_nents(req->src) == 1) {
+ src = kmap_local_page(sg_page(req->src)) + req->src->offset;
+ } else {
+ scatterwalk_map_and_copy(scratch->src, req->src, 0,
+ req->slen, 0);
+ src = scratch->src;
+ }
+
+ if (req->dst && sg_nents(req->dst) == 1) {
+ dst = kmap_local_page(sg_page(req->dst)) + req->dst->offset;
+ } else {
+ dst = scratch->dst;
+ }
+
if (dir)
- ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
- scratch->dst, &req->dlen, *ctx);
+ ret = crypto_scomp_compress(scomp, src, req->slen,
+ dst, &req->dlen, *ctx);
else
- ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
- scratch->dst, &req->dlen, *ctx);
+ ret = crypto_scomp_decompress(scomp, src, req->slen,
+ dst, &req->dlen, *ctx);
if (!ret) {
if (!req->dst) {
req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
@@ -146,10 +160,17 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
goto out;
}
}
- scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
- 1);
+ if (dst == scratch->dst) {
+ scatterwalk_map_and_copy(scratch->dst, req->dst, 0,
+ req->dlen, 1);
+ }
}
out:
+ if (src != scratch->src)
+ kunmap_local(src);
+ if (dst != scratch->dst)
+ kunmap_local(dst);
+
spin_unlock(&scratch->lock);
return ret;
}
--
2.34.1
parent reply other threads:[~2024-01-03 5:31 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <5aff3bcf-ef36-45b3-8ac0-a4b19697419c@bytedance.com>]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240103053134.564457-1-21cnbao@gmail.com \
--to=21cnbao@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=chriscli@google.com \
--cc=chrisl@kernel.org \
--cc=davem@davemloft.net \
--cc=ddstreet@ieee.org \
--cc=hannes@cmpxchg.org \
--cc=herbert@gondor.apana.org.au \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=nphamcs@gmail.com \
--cc=sjenning@redhat.com \
--cc=v-songbaohua@oppo.com \
--cc=vitaly.wool@konsulko.com \
--cc=yosryahmed@google.com \
--cc=zhouchengming@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).