From 2e8afe16eb831c227693c37a7da59215e5686134 Mon Sep 17 00:00:00 2001
From: Enzo Matsumiya <ematsumiya@suse.de>
Date: Wed, 14 Aug 2024 13:40:58 -0300
Subject: smb: client: lz77 fast works
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/smb/client/compress/lz77.c | 121 ++++++++++++++++++++----------------------
1 file changed, 59 insertions(+), 62 deletions(-)
diff --git a/fs/smb/client/compress/lz77.c b/fs/smb/client/compress/lz77.c
index 2cbfcf3ed9bf..7d672200d55f 100644
--- a/fs/smb/client/compress/lz77.c
+++ b/fs/smb/client/compress/lz77.c
@@ -40,12 +40,6 @@
#define lz77_read(nbits, _ptr) get_unaligned((const u ## nbits *)(_ptr))
#define lz77_write(nbits, _ptr, _v) put_unaligned_le ## nbits((_v), (typeof((_v)) *)(_ptr))
-struct lz77_flag {
- u8 *pos;
- u32 count;
- long val;
-};
-
static __always_inline u16 lz77_read16(const void *ptr)
{
return lz77_read(16, ptr);
@@ -94,19 +88,9 @@ static __always_inline u32 lz77_count_common_bytes(const u64 diff)
static __always_inline u32 lz77_match_len(const u8 *match, const u8 *cur, const u8 *end)
{
const u8 *start = cur;
- u32 step = sizeof(u32);
+ u32 step = sizeof(u64);
u64 diff;
- if (cur > end - step)
- return 0;
-
- if (lz77_read32(cur) ^ lz77_read32(match))
- return 0;
-
- cur += step;
- match += step;
- step = sizeof(u64);
-
while (likely(cur < end - (step - 1))) {
diff = lz77_read64(cur) ^ lz77_read64(match);
if (!diff) {
@@ -214,39 +198,15 @@ static __always_inline void lz77_copy(u8 *dst, const u8 *src, size_t count)
memcpy(dst, src, count);
}
-static u8 *lz77_write_literals(u8 *dst, const u8 *src, u32 count, struct lz77_flag *flags)
-{
- const u8 *end = src + count;
-
- while (likely(src < end)) {
- u32 c = umin(count, 32 - flags->count);
-
- lz77_copy(dst, src, c);
-
- dst += c;
- src += c;
- count -= c;
-
- flags->val <<= c;
- flags->count += c;
- if (flags->count == 32) {
- lz77_write32(flags->pos, flags->val);
- flags->count = 0;
- flags->pos = dst;
- dst += 4;
- }
- }
-
- return dst;
-}
-
noinline int lz77_compress(const u8 *src, u32 slen, u8 *dst, u32 *dlen)
{
const u8 *srcp, *end, *anchor;
- struct lz77_flag flags = { 0 };
- u8 *dstp, *nib;
+ u8 *dstp, *nib, *flag_pos;
+ u32 flag_count = 0;
u64 *htable;
+ long flag = 0;
int ret;
+ unsigned long s, e;
srcp = src;
anchor = srcp;
@@ -254,15 +214,15 @@ noinline int lz77_compress(const u8 *src, u32 slen, u8 *dst, u32 *dlen)
dstp = dst;
nib = NULL;
-
- /* Output buffer start with a 4 byte flags. */
- flags.pos = dstp;
+ flag_pos = dstp;
dstp += 4;
htable = kvcalloc(LZ77_HASH_SIZE, sizeof(*htable), GFP_KERNEL);
if (!htable)
return -ENOMEM;
+ s = jiffies;
+
/* Main loop. */
while (likely(srcp < end)) {
u32 offset, dist, len;
@@ -271,7 +231,6 @@ noinline int lz77_compress(const u8 *src, u32 slen, u8 *dst, u32 *dlen)
while (likely(srcp + LZ77_MATCH_MIN_LEN < end)) {
offset = srcp - src;
hash = lz77_hash_bytes(srcp);
-
dist = offset - htable[hash];
if (dist >= LZ77_MATCH_MIN_DIST && dist < LZ77_MATCH_MAX_DIST)
len = lz77_match_len(src + htable[hash], srcp, end);
@@ -286,7 +245,23 @@ noinline int lz77_compress(const u8 *src, u32 slen, u8 *dst, u32 *dlen)
srcp++;
}
- dstp = lz77_write_literals(dstp, anchor, srcp - anchor, &flags);
+ while (likely(anchor < srcp)) {
+ u32 c = umin(srcp - anchor, 32 - flag_count);
+
+ lz77_copy(dstp, anchor, c);
+
+ dstp += c;
+ anchor += c;
+
+ flag <<= c;
+ flag_count += c;
+ if (flag_count == 32) {
+ lz77_write32(flag_pos, flag);
+ flag_count = 0;
+ flag_pos = dstp;
+ dstp += 4;
+ }
+ }
if (unlikely(srcp + LZ77_MATCH_MIN_LEN >= end))
goto leftovers;
@@ -295,30 +270,52 @@ noinline int lz77_compress(const u8 *src, u32 slen, u8 *dst, u32 *dlen)
srcp += len;
anchor = srcp;
- flags.val = (flags.val << 1) | 1;
- flags.count++;
- if (flags.count == 32) {
- lz77_write32(flags.pos, flags.val);
- flags.count = 0;
- flags.pos = dstp;
+ flag = (flag << 1) | 1;
+ flag_count++;
+ if (flag_count == 32) {
+ lz77_write32(flag_pos, flag);
+ flag_count = 0;
+ flag_pos = dstp;
dstp += 4;
}
}
leftovers:
- if (srcp < end)
- dstp = lz77_write_literals(dstp, srcp, end - srcp, &flags);
+ if (srcp < end) {
+ while (likely(srcp < end)) {
+ u32 c = umin(end - srcp, 32 - flag_count);
+
+ lz77_copy(dstp, srcp, c);
+
+ dstp += c;
+ srcp += c;
+
+ flag <<= c;
+ flag_count += c;
+ if (flag_count == 32) {
+ lz77_write32(flag_pos, flag);
+ flag_count = 0;
+ flag_pos = dstp;
+ dstp += 4;
+ }
+ }
+ }
- flags.val <<= (32 - flags.count);
- flags.val |= (1 << (32 - flags.count)) - 1;
- lz77_write32(flags.pos, flags.val);
+ flag <<= (32 - flag_count);
+ flag |= (1 << (32 - flag_count)) - 1;
+ lz77_write32(flag_pos, flag);
*dlen = dstp - (u8 *)dst;
+
+ e = jiffies;
+ pr_err("%s: (fast) took %ums to compress (slen=%u, dlen=%u)\n", __func__, jiffies_to_msecs(e - s), slen, *dlen);
+
if (*dlen < slen)
ret = 0;
else
ret = -EMSGSIZE;
-//out:
+
kvfree(htable);
+
return ret;
}
--
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