Re: [PATCH] make the MAX_MALLOC_BUFS customizable
by lijiang
Hi, Shivang
Thank you for the patch.
On Thu, Nov 20, 2025 at 4:18 AM <devel-request(a)lists.crash-utility.osci.io>
wrote:
> Date: Wed, 19 Nov 2025 16:23:46 +0530
> From: Shivang Upadhyay <shivangu(a)linux.ibm.com>
> Subject: [Crash-utility] [PATCH] make the MAX_MALLOC_BUFS customizable
> To: k-hagio-ab(a)nec.com, lijiang(a)redhat.com
> Cc: shivangu(a)linux.ibm.com, devel(a)lists.crash-utility.osci.io
> Message-ID: <20251119105346.24902-1-shivangu(a)linux.ibm.com>
>
> default value is kept to 2000, but can be changed with
> command line with flag `--max-malloc-bufs`.
>
> Signed-off-by: Shivang Upadhyay <shivangu(a)linux.ibm.com>
> ---
> defs.h | 1 +
> main.c | 4 ++++
> tools.c | 9 ++++++---
> 3 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/defs.h b/defs.h
> index ab4aee8..863baf9 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -5608,6 +5608,7 @@ void exec_args_input_file(struct command_table_entry
> *, struct args_input_file *
> /*
> * tools.c
> */
> +extern int MAX_MALLOC_BUFS;
> FILE *set_error(char *);
> int __error(int, char *, ...);
> #define error __error /* avoid conflict with gdb error() */
> diff --git a/main.c b/main.c
> index 71bcc15..e986792 100644
> --- a/main.c
> +++ b/main.c
> @@ -46,6 +46,7 @@ static struct option long_options[] = {
> {"version", 0, 0, 0},
> {"buildinfo", 0, 0, 0},
> {"cpus", required_argument, 0, 0},
> + {"max-malloc-bufs", required_argument, 0, 0},
> {"no_ikconfig", 0, 0, 0},
> {"hyper", 0, 0, 0},
> {"p2m_mfn", required_argument, 0, 0},
> @@ -163,6 +164,9 @@ main(int argc, char **argv)
> else if (STREQ(long_options[option_index].name,
> "cpus"))
> kt->cpus_override = optarg;
>
> + else if (STREQ(long_options[option_index].name,
> "max-malloc-bufs"))
> + MAX_MALLOC_BUFS = atoi(optarg);
> +
> else if (STREQ(long_options[option_index].name,
> "hyper"))
> pc->flags |= XEN_HYPER;
>
> diff --git a/tools.c b/tools.c
> index a9ad18d..c9867e1 100644
> --- a/tools.c
> +++ b/tools.c
> @@ -5698,7 +5698,7 @@ ll_power(long long base, long long exp)
> #define B32K (4)
>
> #define SHARED_BUF_SIZES (B32K+1)
> -#define MAX_MALLOC_BUFS (2000)
> +int MAX_MALLOC_BUFS = 2000; /* can be changed from command line args */
>
Think it again and discuss with customers, that should be good to fold
these two patches into one patch:
https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01829.html
That is to say, increase the default MAX_MALLOC_BUFS and also introduce the
--max-malloc-bufs options, which can handle both cases:
1. most customers never hit the max limit
2. deal with large vmcores without blocking analysis
What do you think?
Thank
Lianbo
#define MAX_CACHE_SIZE (KILOBYTES(32))
>
> struct shared_bufs {
> @@ -5723,7 +5723,7 @@ struct shared_bufs {
> long buf_8K_ovf;
> long buf_32K_ovf;
> int buf_inuse[SHARED_BUF_SIZES];
> - char *malloc_bp[MAX_MALLOC_BUFS];
> + char **malloc_bp;
> long smallest;
> long largest;
> long embedded;
> @@ -5744,6 +5744,7 @@ buf_init(void)
>
> bp->smallest = 0x7fffffff;
> bp->total = 0.0;
> + bp->malloc_bp = (char**) calloc(MAX_MALLOC_BUFS * sizeof(char*),
> 1);
>
> #ifdef VALGRIND
> VALGRIND_MAKE_MEM_NOACCESS(&bp->buf_1K, sizeof(bp->buf_1K));
> @@ -6130,7 +6131,9 @@ getbuf(long reqsize)
> dump_shared_bufs();
>
> return ((char *)(long)
> - error(FATAL, "cannot allocate any more memory!\n"));
> + error(FATAL, "cannot allocate any more memory!\n"
> + "try increasing --max-malloc-bufs
> (current value : %d)\n",
> + MAX_MALLOC_BUFS));
> }
>
> /*
> --
> 2.51.0
>
2 months, 1 week
[PATCH] Ensure all child processes are properly cleaned up in restore_ifile_sanity
by neilfsun
Run input file with pipe cmdlines will get nothing output.
crash> p cpu_info:0 | grep 'x86 ='
x86 = 0x19,
crash> cat crashrc
p cpu_info:0 | grep 'x86 ='
p cpu_info:0 | grep 'x86 ='
crash> < crashrc
crash> p cpu_info:0 | grep 'x86 ='
x86 = 0x19,
crash> p cpu_info:0 | grep 'x86 ='
crash>
Signed-off-by: neilfsun <neilfsun(a)tencent.com>
Signed-off-by: Feng Sun <loyou85(a)gmail.com>
---
cmdline.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/cmdline.c b/cmdline.c
index 65da04c..4add548 100644
--- a/cmdline.c
+++ b/cmdline.c
@@ -1285,6 +1285,8 @@ restore_ifile_sanity(void)
close_tmpfile2();
}
+ wait_for_children(ALL_CHILDREN);
+
restore_gdb_sanity();
free_all_bufs();
--
2.50.1
2 months, 1 week
[PATCH] Fix "timer -r" option on Linux 6.18 and later kernels
by HAGIO KAZUHITO(萩尾 一仁)
Kernel commit 009eb5da29a9 ("hrtimer: Remove hrtimer_clock_base::
Get_time") removed the get_time member from struct hrtimer_clock_base.
As a result, the "timer -r" option fails with the following error:
crash> timer -r
timer: invalid structure member offset: hrtimer_clock_base_get_time
FILE: kernel.c LINE: 7953 FUNCTION: dump_hrtimer_clock_base()
As the get_time function is switched by __hrtimer_cb_get_time() function
with clock_id macro value, crash cannot follow their changes
automatically. So change what "timer -r" displays there from the
get_time function name to enum hrtimer_base_type name.
Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
---
I refered to page_flags_init_from_pageflags_enum() function to use
dump_enumerator_list(), pc->flags2 and etc.
defs.h | 1 +
kernel.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++----
symbols.c | 2 ++
3 files changed, 73 insertions(+), 5 deletions(-)
diff --git a/defs.h b/defs.h
index ab4aee8520a7..7f87e8e939e9 100644
--- a/defs.h
+++ b/defs.h
@@ -2280,6 +2280,7 @@ struct offset_table { /* stash of commonly-used offsets */
long bpf_ringbuf_map_rb;
long bpf_ringbuf_consumer_pos;
long bpf_ringbuf_nr_pages;
+ long hrtimer_clock_base_index;
};
struct size_table { /* stash of commonly-used sizes */
diff --git a/kernel.c b/kernel.c
index 13f33742990e..ec287bb55c05 100644
--- a/kernel.c
+++ b/kernel.c
@@ -43,6 +43,7 @@ static void display_bh_1(void);
static void display_bh_2(void);
static void display_bh_3(void);
static void display_bh_4(void);
+static int hrtimer_base_type_init(void);
static void dump_hrtimer_data(const ulong *cpus);
static void dump_hrtimer_clock_base(const void *, const int);
static void dump_hrtimer_base(const void *, const int);
@@ -796,6 +797,12 @@ kernel_init()
"hrtimer_clock_base", "first");
MEMBER_OFFSET_INIT(hrtimer_clock_base_get_time,
"hrtimer_clock_base", "get_time");
+ if (INVALID_MEMBER(hrtimer_clock_base_get_time)) {
+ /* Linux 6.18: 009eb5da29a9 */
+ MEMBER_OFFSET_INIT(hrtimer_clock_base_index, "hrtimer_clock_base", "index");
+ if (!hrtimer_base_type_init())
+ error(WARNING, "cannot get enum hrtimer_base_type\n");
+ }
}
STRUCT_SIZE_INIT(hrtimer_base, "hrtimer_base");
@@ -7938,6 +7945,52 @@ static int expires_len = -1;
static int softexpires_len = -1;
static int tte_len = -1;
+static char **hrtimer_base_type = NULL;
+static int
+hrtimer_base_type_init(void)
+{
+ long max_bases;
+ int i, c ATTRIBUTE_UNUSED;
+ char buf[BUFSIZE];
+ char *arglist[MAXARGS];
+
+ if (!enumerator_value("HRTIMER_MAX_CLOCK_BASES", &max_bases))
+ return FALSE;
+
+ hrtimer_base_type = (char **)calloc(max_bases, sizeof(char *));
+ if (!hrtimer_base_type)
+ return FALSE;
+
+ pc->flags2 |= ALLOW_FP; /* Required during initialization */
+ open_tmpfile();
+ if (dump_enumerator_list("hrtimer_base_type")) {
+ rewind(pc->tmpfile);
+ while (fgets(buf, BUFSIZE, pc->tmpfile)) {
+ if (!strstr(buf, " = "))
+ continue;
+ c = parse_line(buf, arglist);
+ i = atoi(arglist[2]);
+ if (0 <= i && i < max_bases)
+ hrtimer_base_type[i] = strdup(arglist[0]);
+ }
+ close_tmpfile();
+ pc->flags2 &= ~ALLOW_FP;
+ } else {
+ close_tmpfile();
+ pc->flags2 &= ~ALLOW_FP;
+ free(hrtimer_base_type);
+ hrtimer_base_type = NULL;
+ return FALSE;
+ }
+
+ if (CRASHDEBUG(1)) {
+ for (i = 0; i < max_bases; i++)
+ fprintf(fp, "hrtimer_base_type[%d] = %s\n", i, hrtimer_base_type[i]);
+ }
+
+ return TRUE;
+}
+
static void
dump_hrtimer_clock_base(const void *hrtimer_bases, const int num)
{
@@ -7949,11 +8002,23 @@ dump_hrtimer_clock_base(const void *hrtimer_bases, const int num)
base = (void *)hrtimer_bases + OFFSET(hrtimer_cpu_base_clock_base) +
SIZE(hrtimer_clock_base) * num;
- readmem((ulong)(base + OFFSET(hrtimer_clock_base_get_time)), KVADDR,
- &get_time, sizeof(get_time), "hrtimer_clock_base get_time",
- FAULT_ON_ERROR);
- fprintf(fp, " CLOCK: %d HRTIMER_CLOCK_BASE: %lx [%s]\n", num,
- (ulong)base, value_to_symstr(get_time, buf, 0));
+
+ if (INVALID_MEMBER(hrtimer_clock_base_get_time)) {
+ /* Linux 6.18: 009eb5da29a9 */
+ if (hrtimer_base_type) {
+ uint index;
+ readmem((ulong)(base + OFFSET(hrtimer_clock_base_index)), KVADDR, &index,
+ sizeof(index), "hrtimer_clock_base index", FAULT_ON_ERROR);
+ fprintf(fp, " CLOCK: %d HRTIMER_CLOCK_BASE: %lx [%s]\n", num,
+ (ulong)base, hrtimer_base_type[index]);
+ } else
+ fprintf(fp, " CLOCK: %d HRTIMER_CLOCK_BASE: %lx\n", num, (ulong)base);
+ } else {
+ readmem((ulong)(base + OFFSET(hrtimer_clock_base_get_time)), KVADDR, &get_time,
+ sizeof(get_time), "hrtimer_clock_base get_time", FAULT_ON_ERROR);
+ fprintf(fp, " CLOCK: %d HRTIMER_CLOCK_BASE: %lx [%s]\n", num,
+ (ulong)base, value_to_symstr(get_time, buf, 0));
+ }
/* get current time(uptime) */
get_uptime(NULL, ¤t_time);
diff --git a/symbols.c b/symbols.c
index 480fdb6d98b3..c446beb43a76 100644
--- a/symbols.c
+++ b/symbols.c
@@ -11760,6 +11760,8 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(hrtimer_clock_base_first));
fprintf(fp, " hrtimer_clock_base_get_time: %ld\n",
OFFSET(hrtimer_clock_base_get_time));
+ fprintf(fp, " hrtimer_clock_base_index: %ld\n",
+ OFFSET(hrtimer_clock_base_index));
fprintf(fp, " hrtimer_base_first: %ld\n",
OFFSET(hrtimer_base_first));
fprintf(fp, " hrtimer_base_pending: %ld\n",
--
2.31.1
2 months, 1 week
[PATCH] Fix typo: uncompess -> uncompress
by Dominique Martinet
---
Not much to say about this, just happened to run into that building an
aarch64 crash for testing and forgetting to add zstd flag -- thanks for
the cross build option, that was great! :)
diskdump.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/diskdump.c b/diskdump.c
index de907551153d..5d3ef81fc607 100644
--- a/diskdump.c
+++ b/diskdump.c
@@ -1368,7 +1368,7 @@ cache_page(physaddr_t paddr)
} else if (pd.flags & DUMP_DH_COMPRESSED_ZSTD) {
if (!(dd->flags & ZSTD_SUPPORTED)) {
- error(INFO, "%s: uncompess failed: no zstd compression support\n",
+ error(INFO, "%s: uncompress failed: no zstd compression support\n",
DISKDUMP_VALID() ? "diskdump" : "compressed kdump");
return READ_ERROR;
}
@@ -1376,7 +1376,7 @@ cache_page(physaddr_t paddr)
if (!dctx) {
dctx = ZSTD_createDCtx();
if (!dctx) {
- error(INFO, "%s: uncompess failed: cannot create ZSTD_DCtx\n",
+ error(INFO, "%s: uncompress failed: cannot create ZSTD_DCtx\n",
DISKDUMP_VALID() ? "diskdump" : "compressed kdump");
return READ_ERROR;
}
--
2.47.3
2 months, 1 week
[PATCH] Resolve BLK_MQ_F_TAG_HCTX_SHARED at runtime
by Tao Liu
Though upstream kernel have defined BLK_MQ_F_TAG_HCTX_SHARED
as (1 << 3), the value might be set different, e.g. [1]. In
this patch, we will use enumerator_value() to get its value
at runtime, to make the code more adaptable.
[1]: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-8/-/blob...
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
This patch is the follow-up of [2].
[2]: https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01848.html
---
dev.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/dev.c b/dev.c
index 27318e8..127cf5a 100644
--- a/dev.c
+++ b/dev.c
@@ -4326,11 +4326,11 @@ struct bt_iter_data {
#define MQ_RQ_IN_FLIGHT 1
#define REQ_OP_BITS 8
#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
-#define BLK_MQ_F_TAG_HCTX_SHARED (1 << 3)
+static int blk_hctx_shared = 0;
static bool blk_mq_is_shared_tags(unsigned int flags)
{
- return flags & BLK_MQ_F_TAG_HCTX_SHARED;
+ return flags & blk_hctx_shared;
}
static uint op_is_write(uint op)
@@ -4952,6 +4952,7 @@ void diskio_init(void)
MEMBER_OFFSET_INIT(request_queue_tag_set, "request_queue", "tag_set");
MEMBER_OFFSET_INIT(blk_mq_tag_set_flags, "blk_mq_tag_set", "flags");
MEMBER_OFFSET_INIT(blk_mq_tag_set_shared_tags, "blk_mq_tag_set", "shared_tags");
+ enumerator_value("BLK_MQ_F_TAG_HCTX_SHARED", &blk_hctx_shared);
dt->flags |= DISKIO_INIT;
}
--
2.47.0
2 months, 1 week
