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Message-Id: <a6fc4fc33c61be908d4977bcf35e6fb267baca08.1701339358.git.ojaswin@linux.ibm.com>
Date: Thu, 30 Nov 2023 19:23:11 +0530
From: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
To: linux-ext4@...r.kernel.org, "Theodore Ts'o" <tytso@....edu>
Cc: Ritesh Harjani <ritesh.list@...il.com>, linux-kernel@...r.kernel.org,
"Darrick J . Wong" <djwong@...nel.org>, linux-block@...r.kernel.org,
linux-xfs@...r.kernel.org, linux-fsdevel@...r.kernel.org,
John Garry <john.g.garry@...cle.com>, dchinner@...hat.com
Subject: [RFC 2/7] ext4: Factor out size and start prediction from ext4_mb_normalize_request()
As a part of trimming down the size of ext4_mb_normalize_request(), factor
out the logic to predict normalized start and size to a separate function
ext4_mb_pa_predict_size().
This is no functional change in this patch.
Signed-off-by: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
---
fs/ext4/mballoc.c | 95 ++++++++++++++++++++++++++++-------------------
1 file changed, 56 insertions(+), 39 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 0b0aff458efd..3eb7b639d36e 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4394,6 +4394,58 @@ ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac,
*end = new_end;
}
+static void ext4_mb_pa_predict_size(struct ext4_allocation_context *ac,
+ loff_t *start, loff_t *size)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ loff_t new_size = *size;
+ loff_t new_start = *start;
+ int bsbits, max;
+
+ bsbits = ac->ac_sb->s_blocksize_bits;
+ /* max size of free chunks */
+ max = 2 << bsbits;
+
+#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
+ (req <= (size) || max <= (chunk_size))
+
+ if (new_size <= 16 * 1024) {
+ new_size = 16 * 1024;
+ } else if (new_size <= 32 * 1024) {
+ new_size = 32 * 1024;
+ } else if (new_size <= 64 * 1024) {
+ new_size = 64 * 1024;
+ } else if (new_size <= 128 * 1024) {
+ new_size = 128 * 1024;
+ } else if (new_size <= 256 * 1024) {
+ new_size = 256 * 1024;
+ } else if (new_size <= 512 * 1024) {
+ new_size = 512 * 1024;
+ } else if (new_size <= 1024 * 1024) {
+ new_size = 1024 * 1024;
+ } else if (NRL_CHECK_SIZE(new_size, 4 * 1024 * 1024, max, 2 * 1024)) {
+ new_start = ((loff_t)ac->ac_o_ex.fe_logical >>
+ (21 - bsbits)) << 21;
+ new_size = 2 * 1024 * 1024;
+ } else if (NRL_CHECK_SIZE(new_size, 8 * 1024 * 1024, max, 4 * 1024)) {
+ new_start = ((loff_t)ac->ac_o_ex.fe_logical >>
+ (22 - bsbits)) << 22;
+ new_size = 4 * 1024 * 1024;
+ } else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len),
+ (8<<20)>>bsbits, max, 8 * 1024)) {
+ new_start = ((loff_t)ac->ac_o_ex.fe_logical >>
+ (23 - bsbits)) << 23;
+ new_size = 8 * 1024 * 1024;
+ } else {
+ new_start = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
+ new_size = (loff_t) EXT4_C2B(sbi,
+ ac->ac_o_ex.fe_len) << bsbits;
+ }
+
+ *size = new_size;
+ *start = new_start;
+}
+
/*
* Normalization means making request better in terms of
* size and alignment
@@ -4404,7 +4456,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
{
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
struct ext4_super_block *es = sbi->s_es;
- int bsbits, max;
+ int bsbits;
loff_t size, start_off, end;
loff_t orig_size __maybe_unused;
ext4_lblk_t start;
@@ -4438,47 +4490,12 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
size = i_size_read(ac->ac_inode);
orig_size = size;
- /* max size of free chunks */
- max = 2 << bsbits;
-
-#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
- (req <= (size) || max <= (chunk_size))
-
/* first, try to predict filesize */
/* XXX: should this table be tunable? */
start_off = 0;
- if (size <= 16 * 1024) {
- size = 16 * 1024;
- } else if (size <= 32 * 1024) {
- size = 32 * 1024;
- } else if (size <= 64 * 1024) {
- size = 64 * 1024;
- } else if (size <= 128 * 1024) {
- size = 128 * 1024;
- } else if (size <= 256 * 1024) {
- size = 256 * 1024;
- } else if (size <= 512 * 1024) {
- size = 512 * 1024;
- } else if (size <= 1024 * 1024) {
- size = 1024 * 1024;
- } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
- start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
- (21 - bsbits)) << 21;
- size = 2 * 1024 * 1024;
- } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
- start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
- (22 - bsbits)) << 22;
- size = 4 * 1024 * 1024;
- } else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len),
- (8<<20)>>bsbits, max, 8 * 1024)) {
- start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
- (23 - bsbits)) << 23;
- size = 8 * 1024 * 1024;
- } else {
- start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
- size = (loff_t) EXT4_C2B(sbi,
- ac->ac_o_ex.fe_len) << bsbits;
- }
+
+ ext4_mb_pa_predict_size(ac, &start_off, &size);
+
size = size >> bsbits;
start = start_off >> bsbits;
--
2.39.3
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